[Code of Federal Regulations]
[Title 29, Volume 6]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 29CFR1910.1047]
[Page 333-353]
TITLE 29--LABOR
CHAPTER XVII--OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT
OF LABOR
PART 1910--OCCUPATIONAL SAFETY AND HEALTH STANDARDS (CONTINUED)--Table of Contents
Subpart Z--Toxic and Hazardous Substances
Sec. 1910.1047 Ethylene oxide.
(a) Scope and application. (1) This section applies to all
occupational exposures to ethylene oxide (EtO), Chemical Abstracts
Service Registry No. 75-21-8, except as provided in paragraph (a)(2) of
this section.
(2) This section does not apply to the processing, use, or handling
of products containing EtO where objective data are reasonably relied
upon that demonstrate that the product is not capable of releasing EtO
in airborne concentrations at or above the action level, and may not
reasonably be foreseen to release EtO in excess of the excursion limit,
under the expected conditions of processing, use, or handling that will
cause the greatest possible release.
(3) Where products containing EtO are exempted under paragraph
(a)(2) of this section, the employer shall maintain records of the
objective data supporting that exemption and the basis for the
employer's reliance on the data, as provided in paragraph (k)(1) of this
section.
(b) Definitions: For the purpose of this section, the following
definitions shall apply:
Action level means a concentration of airborne EtO of 0.5 ppm
calculated as an eight (8)-hour time-weighted average.
Assistant Secretary means the Assistant Secretary of Labor for
Occupational Safety and Health, U.S. Department of Labor, or designee.
[[Page 334]]
Authorized person means any person specifically authorized by the
employer whose duties require the person to enter a regulated area, or
any person entering such an area as a designated representative of
employees for the purpose of exercising the right to observe monitoring
and measuring procedures under paragraph (l) of this section, or any
other person authorized by the Act or regulations issued under the Act.
Director means the Director of the National Institute for
Occupational Safety and Health, U.S. Department of Health and Human
Services, or designee.
Emergency means any occurrence such as, but not limited to,
equipment failure, rupture of containers, or failure of control
equipment that is likely to or does result in an unexpected significant
release of EtO.
Employee exposure means exposure to airborne EtO which would occur
if the employee were not using respiratory protective equipment.
Ethylene oxide or EtO means the three-membered ring organic compound
with chemical formula C2 H4 O.
(c) Permissible exposure limits--(1) 8-hour time weighted average
(TWA). The employer shall ensure that no employee is exposed to an
airborne concentration of EtO in excess of one (1) part EtO per million
parts of air (1 ppm) as an 8-hour time-weighted average (8-hour TWA).
(2) Excursion limit. The employer shall ensure that no employee is
exposed to an airborne concentration of EtO in excess of 5 parts of EtO
per million parts of air (5 ppm) as averaged over a sampling period of
fifteen (15) minutes.
(d) Exposure monitoring--(1) General. (i) Determinations of employee
exposure shall be made from breathing zone air samples that are
representative of the 8-hour TWA and 15-minute short-term exposures of
each employee.
(ii) Representative 8-hour TWA employee exposure shall be determined
on the basis of one or more samples representing full-shift exposure for
each shift for each job classification in each work area. Representative
15-minute short-term employee exposures shall be determined on the basis
of one or more samples representing 15-minute exposures associated with
operations that are most likely to produce exposures above the excursion
limit for each shift for each job classification in each work area.
(iii) Where the employer can document that exposure levels are
equivalent for similar operations in different work shifts, the employer
need only determine representative employee exposure for that operation
during one shift.
(2) Initial monitoring. (i) Each employer who has a workplace or
work operation covered by this standard, except as provided for in
paragraph (a)(2) or (d)(2)(ii) of this section, shall perform initial
monitoring to determine accurately the airborne concentrations of EtO to
which employees may be exposed.
(ii) Where the employer has monitored after June 15, 1983 and the
monitoring satisfies all other requirements of this section, the
employer may rely on such earlier monitoring results to satisfy the
requirements of paragraph (d)(2)(i) of this section.
(iii) Where the employer has previously monitored for the excursion
limit and the monitoring satisfies all other requirements of this
sections, the employer may rely on such earlier monitoring results to
satisfy the requirements of paragraph (d)(2)(i) of this section.
(3) Monitoring frequency (periodic monitoring). (i) If the
monitoring required by paragraph (d)(2) of this section reveals employee
exposure at or above the action level but at or below the 8-hour TWA,
the employer shall repeat such monitoring for each such employee at
least every 6 months.
(ii) If the monitoring required by paragraph (d)(2)(i) of this
section reveals employee exposure above the 8-hour TWA, the employer
shall repeat such monitoring for each such employee at least every 3
months.
(iii) The employer may alter the monitoring schedule from quarterly
to semiannually for any employee for whom two consecutive measurements
taken at least 7 days apart indicate that the employee's exposure has
decreased to or below the 8-hour TWA.
[[Page 335]]
(iv) If the monitoring required by paragraph (d)(2)(i) of this
section reveals employee exposure above the 15 minute excursion limit,
the employer shall repeat such monitoring for each such employee at
least every 3 months, and more often as necessary to evaluate exposure
the employee's short-term exposures.
(4) Termination of monitoring. (i) If the initial monitoring
required by paragraph (d)(2)(i) of this section reveals employee
exposure to be below the action level, the employer may discontinue TWA
monitoring for those employees whose exposures are represented by the
initial monitoring.
(ii) If the periodic monitoring required by paragraph (d)(3) of this
section reveals that employee exposures, as indicated by at least two
consecutive measurements taken at least 7 days apart, are below the
action level, the employer may discontinue TWA monitoring for those
employees whose exposures are represented by such monitoring.
(iii) If the initial monitoring required by paragraph (d)(2)(1) of
this section reveals employee exposure to be at or below the excursion
limit, the employer may discontinue excursion limit monitoring for those
employees whose exposures are represented by the initial monitoring.
(iv) If the periodic monitoring required by paragraph (d)(3) of this
section reveals that employee exposures, as indicated by at least two
consecutive measurements taken at least 7 days apart, are at or below
the excursion limit, the employer may discontinue excursion limit
monitoring for those employees whose exposures are represented by such
monitoring.
(5) Additional monitoring. Notwithstanding the provisions of
paragraph (d)(4) of this section, the employer shall institute the
exposure monitoring required under paragraphs (d)(2)(i) and (d)(3) of
this section whenever there has been a change in the production,
process, control equipment, personnel or work practices that may result
in new or additional exposures to EtO or when the employer has any
reason to suspect that a change may result in new or additional
exposures.
(6) Accuracy of monitoring. (i) Monitoring shall be accurate, to a
confidence level of 95 percent, to within plus or minus 25 percent for
airborne concentrations of EtO at the 1 ppm TWA and to within plus or
minus 35 percent for airborne concentrations of EtO at the action level
of 0.5 ppm.
(ii) Monitoring shall be accurate, to a confidence level of 95
percent, to within plus or minus 35 percent for airborne concentrations
of EtO at the excursion limit.
(7) Employee notification of monitoring results. (i) The employer
shall, within 15 working days after the receipt of the results of any
monitoring performed under this standard, notify the affected employee
of these results in writing either individually or by posting of results
in an appropriate location that is accessible to affected employees.
(ii) The written notification required by paragraph (d)(7)(i) of
this section shall contain the corrective action being taken by the
employer to reduce employee exposure to or below the TWA and/or
excursion limit, wherever monitoring results indicated that the TWA and/
or excursion limit has been exceeded.
(e) Regulated areas. (1) The employer shall establish a regulated
area wherever occupational exposure to airborne concentrations of EtO
may exceed the TWA or wherever the EtO concentration exceeds or can
reasonably be expected to exceed the excursion limit.
(2) Access to regulated areas shall be limited to authorized
persons.
(3) Regulated areas shall be demarcated in any manner that minimizes
the number of employees within the regulated area.
(f) Methods of compliance. (1) Engineering controls and work
practices. (i) The employer shall institute engineering controls and
work practices to reduce and maintain employee exposure to or below the
TWA and to or below the excursion limit, except to the extent that such
controls are not feasible.
(ii) Wherever the feasible engineering controls and work practices
that can be instituted are not sufficient to reduce employee exposure to
or below the TWA and to or below the excursion limit, the employer shall
use them to reduce employee exposure to the lowest
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levels achievable by these controls and shall supplement them by the use
of respiratory protection that complies with the requirements of
paragraph (g) of this section.
(iii) Engineering controls are generally infeasible for the
following operations: collection of quality assurance sampling from
sterilized materials removal of biological indicators from sterilized
materials: loading and unloading of tank cars; changing of ethylene
oxide tanks on sterilizers; and vessel cleaning. For these operations,
engineering controls are required only where the Assistant Secretary
demonstrates that such controls are feasible.
(2) Compliance program. (i) Where the TWA or excursion limit is
exceeded, the employer shall establish and implement a written program
to reduce exposure to or below the TWA and to or below the excursion
limit by means of engineering and work practice controls, as required by
paragraph (f)(1) of this section, and by the use of respiratory
protection where required or permitted under this section.
(ii) The compliance program shall include a schedule for periodic
leak detection surveys and a written plan for emergency situations, as
specified in paragraph (h)(i) of this section.
(iii) Written plans for a program required in paragraph (f)(2) shall
be developed and furnished upon request for examination and copying to
the Assistant Secretary, the Director, affected employees and designated
employee representatives. Such plans shall be reviewed at least every 12
months, and shall be updated as necessary to reflect significant changes
in the status of the employer's compliance program.
(iv) The employer shall not implement a schedule of employee
rotation as a means of compliance with the TWA or excursion limit.
(g) Respiratory protection and personal protective equipment--(1)
General. For employees who use respirators required by this section, the
employer must provide respirators that comply with the requirements of
this paragraph. Respirators must be used during:
(i) Periods necessary to install or implement feasible engineering
and work-practice controls.
(ii) Work operations, such as maintenance and repair activities and
vessel cleaning, for which engineering and work-practice controls are
not feasible.
(iii) Work operations for which feasible engineering and work-
practice controls are not yet sufficient to reduce employee exposure to
or below the TWA.
(iv) Emergencies.
(2) Respirator program. The employer must implement a respiratory
protection program in accordance with 29 CFR 1910.134 (b) through (d)
(except (d)(1)(iii)), and (f) through (m).
(3) Respirator selection. The employer must select the appropriate
respirator from Table 1 of this section.
Table 1--Minimum Requirements for Respiratory Protection for Airborne
EtO
------------------------------------------------------------------------
Condition of use or
concentration of airborne EtO Minimum required respirator
(ppm)
------------------------------------------------------------------------
Equal to or less than 50..... (a) Full facepiece respirator with EtO
approved canister, front-or back-
mounted.
Equal to or less than 2,000.. (a) Positive-pressure supplied air
respirator, equipped with full
facepiece, hood, or helmet, or
(b) Continuous-flow supplied air
respirator (positive pressure) equipped
with hood, helmet or suit.
Concentration above 2,000 or (a) Positive-pressure self-contained
unknown concentration (such breathing apparatus (SCBA), equipped
as in emergencies). with full facepiece, or
(b) Positive-pressure full facepiece
supplied air respirator equipped with an
auxiliary positive-pressure self-
contained breathing apparatus.
Firefighting................. (a) Positive pressure self-contained
breathing apparatus equipped with full
facepiece.
Escape....................... (a) Any respirator described above.
------------------------------------------------------------------------
Note. Respirators approved for use in higher concentrations are
permitted to be used in lower concentrations.
(4) Protective clothing and equipment. When employees could have eye
or skin contact with EtO or EtO solutions, the employer must select and
provide, at no cost to the employee, appropriate protective clothing or
other equipment
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in accordance with 29 CFR 1910.132 and 1910.133 to protect any area of
the employee's body that may come in contact with the EtO or EtO
solution, and must ensure that the employee wears the protective
clothing and equipment provided.
(h) Emergency situations--(1) Written plan. (i) A written plan for
emergency situations shall be developed for each workplace where there
is a possibility of an emergency. Appropriate portions of the plan shall
be implemented in the event of an emergency.
(ii) The plan shall specifically provide that employees engaged in
correcting emergency conditions shall be equipped with respiratory
protection as required by paragraph (g) of this section until the
emergency is abated.
(iii) The plan shall include the elements prescribed in 29 CFR
1910.38 and 29 CFR 1910.39, ``Emergency action plans'' and ``Fire
prevention plans,'' respectively.
(2) Alerting employees. Where there is the possibility of employee
exposure to EtO due to an emergency, means shall be developed to alert
potentially affected employees of such occurrences promptly. Affected
employees shall be immediately evacuated from the area in the event that
an emergency occurs.
(i) Medical Surveillance--(1) General--(i) Employees covered. (A)
The employer shall institute a medical surveillance program for all
employees who are or may be exposed to EtO at or above the action level,
without regard to the use of respirators, for at least 30 days a year.
(B) The employer shall make available medical examinations and
consultations to all employees who have been exposed to EtO in an
emergency situation.
(ii) Examination by a physician. The employer shall ensure that all
medical examinations and procedures are performed by or under the
supervision of a licensed physician, and are provided without cost to
the employee, without loss of pay, and at a reasonable time and place.
(2) Medical examinations and consultations--(i) Frequency. The
employer shall make available medical examinations and consultations to
each employee covered under paragraph (i)(1)(i) of this section on the
following schedules:
(A) Prior to assignment of the employee to an area where exposure
may be at or above the action level for at least 30 days a year.
(B) At least annually each employee exposed at or above the action
level for at least 30 days in the past year.
(C) At termination of employment or reassignment to an area where
exposure to EtO is not at or above the action level for at least 30 days
a year.
(D) As medically appropriate for any employee exposed during an
emergency.
(E) As soon as possible, upon notification by an employee either (1)
that the employee has developed signs or symptoms indicating possible
overexposure to EtO, or (2) that the employee desires medical advice
concerning the effects of current or past exposure to EtO on the
employee's ability to produce a healthy child.
(F) If the examining physician determines that any of the
examinations should be provided more frequently than specified, the
employer shall provide such examinations to affected employees at the
frequencies recommended by the physician.
(ii) Content. (A) Medical examinations made available pursuant to
paragraphs (i)(2)(i)(A)-(D) of this section shall include:
(1) A medical and work history with special emphasis directed to
symptoms related to the pulmonary, hematologic, neurologic, and
reproductive systems and to the eyes and skin.
(2) A physical examination with particular emphasis given to the
pulmonary, hematologic, neurologic, and reproductive systems and to the
eyes and skin.
(3) A complete blood count to include at least a white cell count
(including differential cell count), red cell count, hematocrit, and
hemoglobin.
(4) Any laboratory or other test which the examining physician deems
necessary by sound medical practice.
(B) The content of medical examinations or consultation made
available pursuant to paragraph (i)(2)(i)(E) of this section shall be
determined by the examining physician, and shall include
[[Page 338]]
pregnancy testing or laboratory evaluation of fertility, if requested by
the employee and deemed appropriate by the physician.
(3) Information provided to the physician. The employer shall
provide the following information to the examining physician:
(i) A copy of this standard and Appendices A, B, and C.
(ii) A description of the affected employee's duties as they relate
to the employee's exposure.
(iii) The employee's representative exposure level or anticipated
exposure level.
(iv) A description of any personal protective and respiratory
equipment used or to be used.
(v) Information from previous medical examinations of the affected
employee that is not otherwise available to the examining physician.
(4) Physician's written opinion. (i) The employer shall obtain a
written opinion from the examining physician. This written opinion shall
contain the results of the medical examination and shall include:
(A) The physician's opinion as to whether the employee has any
detected medical conditions that would place the employee at an
increased risk of material health impairment from exposure to EtO;
(B) Any recommended limitations on the employee or upon the use of
personal protective equipment such as clothing or respirators; and
(C) A statement that the employee has been informed by the physician
of the results of the medical examination and of any medical conditions
resulting from EtO exposure that require further explanation or
treatment.
(ii) The employer shall instruct the physician not to reveal in the
written opinion given to the employer specific findings or diagnoses
unrelated to occupational exposure to EtO.
(iii) The employer shall provide a copy of the physician's written
opinion to the affected employee within 15 days from its receipt.
(j) Communication of EtO hazards to employees--(1) Signs and labels.
(i) The employer shall post and maintain legible signs demarcating
regulated areas and entrances or accessways to regulated areas that bear
the following legend:
DANGER
ETHYLENE OXIDE
CANCER HAZARD AND REPRODUCTIVE HAZARD
AUTHORIZED PERSONNEL ONLY
RESPIRATORS AND PROTECTIVE CLOTHING MAY BE REQUIRED
TO BE WORN IN THIS AREA
(ii) The employer shall ensure that precautionary labels are affixed
to all containers of EtO whose contents are capable of causing employee
exposure at or above the action level or whose contents may reasonably
be foreseen to cause employee exposure above the excursion limit, and
that the labels remain affixed when the containers of EtO leave the
workplace. For the purpose of this paragraph, reaction vessels, storage
tanks, and pipes or piping systems are not considered to be containers.
The labels shall comply with the requirements of 29 CFR 1910.1200(f) of
OSHA's Hazard Communication standard, and shall include the following
legend:
(A) DANGER
CONTAINS ETHYLENE OXIDE
CANCER HAZARD AND REPRODUCTIVE HAZARD;
and
(B) A warning statement against breathing airborne concentrations of
EtO.
(iii) The labeling requirements under this section do not apply
where EtO is used as a pesticide, as such term is defined in the Federal
Insecticide. Fungicide, and Rodenticide Act (7 U.S.C. 136 et seq.), when
it is labeled pursuant to that Act and regulations issued under that Act
by the Environmental Protection Agency.
(2) Material safety data sheets. Employers who are manufacturers or
importers of EtO shall comply with the requirements regarding
development of material safety data sheets as specified in 29 CFR
1910.1200(g) of OSHA's Hazard Communication standard.
(3) Information and training. (i) The employer shall provide
employees who are potentially exposed to EtO at or above the action
level or above the excursion limit with information and training on EtO
at the time of initial
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assignment and at least annually thereafter.
(ii) Employees shall be informed of the following:
(A) The requirements of this section with an explanation of its
contents, including Appendices A and B;
(B) Any operations in their work area where EtO is present;
(C) The location and availability of the written EtO final rule; and
(D) The medical surveillance program required by paragraph (i) of
this section with an explanation of the information in Appendix C.
(iii) Employee training shall include at least:
(A) Methods and observations that may be used to detect the presence
or release of EtO in the work area (such as monitoring conducted by the
employer, continuous monitoring devices, etc.);
(B) The physical and health hazards of EtO;
(C) The measures employees can take to protect themselves from
hazards associated with EtO exposure, including specific procedures the
employer has implemented to protect employees from exposure to EtO, such
as work practices, emergency procedures, and personal protective
equipment to be used; and
(D) The details of the hazard communication program developed by the
employer, including an explanation of the labeling system and how
employees can obtain and use the appropriate hazard information.
(k) Recordkeeping--(1) Objective data for exempted operations. (i)
Where the processing, use, or handling of products made from or
containing EtO are exempted from other requirements of this section
under paragraph (a)(2) of this section, or where objective data have
been relied on in lieu of initial monitoring under paragraph (d)(2)(ii)
of this section, the employer shall establish and maintain an accurate
record of objective data reasonably relied upon in support of the
exemption.
(ii) This record shall include at least the following information:
(A) The product qualifying for exemption;
(B) The source of the objective data;
(C) The testing protocol, results of testing, and/or analysis of the
material for the release of EtO;
(D) A description of the operation exempted and how the data support
the exemption; and
(E) Other data relevant to the operations, materials, processing, or
employee exposures covered by the exemption.
(iii) The employer shall maintain this record for the duration of
the employer's reliance upon such objective data.
(2) Exposure measurements. (i) The employer shall keep an accurate
record of all measurements taken to monitor employee exposure to EtO as
prescribed in paragraph (d) of this section.
(ii) This record shall include at least the following information:
(A) The date of measurement;
(B) The operation involving exposure to EtO which is being
monitored;
(C) Sampling and analytical methods used and evidence of their
accuracy;
(D) Number, duration, and results of samples taken;
(E) Type of protective devices worn, if any; and
(F) Name, social security number and exposure of the employees whose
exposures are represented.
(iii) The employer shall maintain this record for at least thirty
(30) years, in accordance with 29 CFR 1910.20.
(3) Medical surveillance. (i) The employer shall establish and
maintain an accurate record for each employee subject to medical
surveillance by paragraph (i)(1)(i) of this section, in accordance with
29 CFR 1910.20.
(ii) The record shall include at least the following information:
(A) The name and social security number of the employee;
(B) Physicians' written opinions;
(C) Any employee medical complaints related to exposure to EtO; and
(D) A copy of the information provided to the physician as required
by paragraph (i)(3) of this section.
(iii) The employer shall ensure that this record is maintained for
the duration of employment plus thirty (30) years, in accordance with 29
CFR 1910.20.
[[Page 340]]
(4) Availability. (i) The employer, upon written request, shall make
all records required to be maintained by this section available to the
Assistant Secretary and the Director for examination and copying.
(ii) The employer, upon request, shall make any exemption and
exposure records required by paragraphs (k) (1) and (2) of this section
available for examination and copying to affected employees, former
employees, designated representatives and the Assistant Secretary, in
accordance with 29 CFR 1910.20 (a) through (e) and (g) through (i).
(iii) The employer, upon request, shall make employee medical
records required by paragraph (k)(3) of this section available for
examination and copying to the subject employee, anyone having the
specific written consent of the subject employee, and the Assistant
Secretary, in accordance with 29 CFR 1910.20.
(5) Transfer of records. (i) The employer shall comply with the
requirements concerning transfer of records set forth in 29 CFR
1910.20(h).
(ii) Whenever the employer ceases to do business and there is no
successor employer to receive and retain the records for the prescribed
period, the employer shall notify the Director at least 90 days prior to
disposal and transmit them to the Director.
(l) Observation of monitoring--(1) Employee observation. The
employer shall provide affected employees or their designated
representatives an opportunity to observe any monitoring of employee
exposure to EtO conducted in accordance with paragraph (d) of this
section.
(2) Observation procedures. When observation of the monitoring of
employee exposure to EtO requires entry into an area where the use of
protective clothing or equipment is required, the observer shall be
provided with and be required to use such clothing and equipment and
shall comply with all other applicable safety and health procedures.
(m) Dates--(1)(i) Effective date. The paragraphs contained in this
section shall become effective August 21, 1984, except for paragraphs
(a)(2), (d), (e), (f)(2), (g)(3), (h), (i), and (j) which shall become
effective on March 12, 1985.
(ii) The requirements in this section which pertain only to or are
triggered by the excursion limit shall become effective June 6, 1988,
except for the excursion limit provisions in paragraphs (a)(2), (d),
(f)(2), (g)(3) and (j) of this section which shall become effective
August 25, 1988.
(2) Start-up dates. (i) The start-up date for the requirements in
those paragraphs that were effective on August 21, 1984, including
institution of work practice controls specified in paragraph (f)(1),
shall be February 19, 1985, except as provided for in paragraph
(m)(2)(ii), and the start-up date for paragraphs (a)(2), (d), (e),
(f)(2), (g)(3), (h), (i), and (j) of this section shall be September 9,
1985.
(ii) Engineering controls specified by paragraph (f)(1) of this
section shall be implemented by August 21, 1985.
(iii) Compliance with the requirements in this section which pertain
only to or are triggered by the excursion limit shall be by September 6,
1988, except for compliance with the excursion limit provisions of
paragraphs (a)(2), (d), (f)(2), (g)(3), and (j) of this section, which
shall be by October 6, 1988, and implementation of engineering controls
specified for compliance with the excursion limit, which shall be by
December 6, 1988.
(3) Labeling. (i) Paragraph (j)(1)(ii)(A) of this section as amended
is effective January 9, 1986.
(ii) Paragraph (j)(1)(iii) of this is effective October 11, 1985.
(n) Appendices. The information contained in the appendices is not
intended by itself to create any additional obligations not otherwise
imposed or to detract from any existing obligation.
Appendix A to Sec. 1910.1047--Substance Safety Data Sheet for Ethylene
Oxide (Non-Mandatory)
i. Substance Identification
A. Substance: Ethylene oxide (C2 H4 O).
B. Synonyms: dihydrooxirene, dimethylene oxide, EO, 1,2-epoxyethane,
EtO, ETO, oxacyclopropane, oxane, oxidoethane, alpha/beta-oxidoethane,
oxiran, oxirane.
C. Ethylene oxide can be found as a liquid or vapor.
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D. EtO is used in the manufacture of ethylene glycol, surfactants,
ethanolamines, glycol ethers, and other organic chemicals. EtO is also
used as a sterilant and fumigant.
E. Appearance and odor: Colorless liquid below 10.7 deg.C (51.3
deg.F) or colorless gas with ether-like odor detected at approximately
700 parts EtO per million parts of air (700 ppm).
F. Permissible Exposure: Exposure may not exceed 1 part EtO per
million parts of air averaged over the 8-hour workday.
ii. Health Hazard Data
A. Ethylene oxide can cause bodily harm if you inhale the vapor, if
it comes into contact with your eyes or skin, or if you swallow it.
B. Effects of overexposure:
1. Ethylene oxide in liquid form can cause eye irritation and injury
to the cornea, frostbite, and severe irritation and blistering of the
skin upon prolonged or confined contact. Ingestion of EtO can cause
gastric irritation and liver injury. Acute effects from inhalation of
EtO vapors include respiratory irritation and lung injury, headache,
nausea, vomiting, diarrhea, shortness of breath, and cyaonosis (blue or
purple coloring of skin). Exposure has also been associated with the
occurrence of cancer, reproductive effects, mutagenic changes,
neurotoxicity, and sensitization.
1. EtO has been shown to cause cancer in laboratory animals and has
been associated with higher incidences of cancer in humans. Adverse
reproductive effects and chromosome damage may also occur from EtO
exposure.
a. Reporting signs and symptoms: You should inform your employer if
you develop any signs or symptoms and suspect that they are caused by
exposure to EtO.
iii. Emergency First Aid Procedures
A. Eye exposure: If EtO gets into your eyes, wash your eyes
immediately with large amounts of water, lifting the lower and upper
eyelids. Get medical attention immediately. Contact lenses should not be
worn when working with this chemical.
B. Skin exposure: If EtO gets on your skin, immediately wash the
contaminated skin with water. If EtO soaks through your clothing,
especially your shoes, remove the clothing immediately and wash the skin
with water using an emergency deluge shower. Get medical attention
immediately. Thoroughly wash contaminated clothing before reusing.
Contaminated leather shoes or other leather articles should not be
reused and should be discarded.
C. Inhalation: If large amounts of EtO are inhaled, the exposed
person must be moved to fresh air at once. If breathing has stopped,
perform cardiopulmonary resuscitation. Keep the affected person warm and
at rest. Get medical attention immediately.
D. Swallowing: When EtO has been swallowed, give the person large
quantities of water immediately. After the water has been swallowed, try
to get the person to vomit by having him or her touch the back of the
throat with his or her finger. Do not make an unconscious person vomit.
Get medical attention immediately.
E. Rescue: Move the affected person from the hazardous exposure. If
the exposed person has been overcome, attempt rescue only after
notifying at least one other person of the emergency and putting into
effect established emergency procedures. Do not become a casualty
yourself. Understand your emergency rescue procedures and know the
location of the emergency equipment before the need arises.
iv. Respirators and Protective Clothing
A. Respirators. You may be required to wear a respirator for
nonroutine activities, in emergencies, while your employer is in the
process of reducing EtO exposures through engineering controls, and in
areas where engineering controls are not feasible. As of the effective
date of this standard, only air-supplied, positive-pressure, full-
facepiece respirators are approved for protection against EtO. If air-
purifying respirators are worn in the future, they must have a label
issued by the National Institute for Occupational Safety and Health
under the provisions of 42 CFR part 84 stating that the respirators have
been approved for use with ethylene oxide. For effective protection,
respirators must fit your face and head snugly. Respirators must not be
loosened or removed in work situations where their use is required.
EtO does not have a detectable odor except at levels well above the
permissible exposure limits. If you can smell EtO while wearing a
respirator, proceed immediately to fresh air. If you experience
difficulty breathing while wearing a respirator, tell your employer.
B. Protective clothing: You may be required to wear impermeable
clothing, gloves, a face shield, or other appropriate protective
clothing to prevent skin contact with liquid EtO or EtO-containing
solutions. Where protective clothing is required, your employer must
provide clean garments to you as necessary to assure that the clothing
protects you adequately.
Replace or repair protective clothing that has become torn or
otherwise damaged.
EtO must never be allowed to remain on the skin. Clothing and shoes
which are not impermeable to EtO should not be allowed to become
contaminated with EtO, and if they do, the clothing should be promptly
removed and decontaminated. Contaminated leather
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shoes should be discarded. Once EtO penetrates shoes or other leather
articles, they should not be worn again.
C. Eye protection: You must wear splashproof safety goggles in areas
where liquid EtO or EtO-containing solutions may contact your eyes. In
addition, contact lenses should not be worn in areas where eye contact
with EtO can occur.
v. Precautions for Safe Use, Handling, and Storage
A. EtO is a flammable liquid, and its vapors can easily form
explosive mixtures in air.
B. EtO must be stored in tighly closed containers in a cool, well-
ventilated area, away from heat, sparks, flames, strong oxidizers,
alkalines, and acids, strong bases, acetylide-forming metals such as
cooper, silver, mercury and their alloys.
C. Sources of ignition such as smoking material, open flames and
some electrical devices are prohibited wherever EtO is handled, used, or
stored in a manner that could create a potential fire or explosion
hazard.
D. You should use non-sparking tools when opening or closing metal
containers of EtO, and containers must be bonded and grounded in the
rare instances in which liquid EtO is poured or transferred.
E. Impermeable clothing wet with liquid EtO or EtO-containing
solutions may be easily ignited. If your are wearing impermeable
clothing and are splashed with liquid EtO or EtO-containing solution,
you should immediately remove the clothing while under an emergency
deluge shower.
F. If your skin comes into contact with liquid EtO or EtO-containing
solutions, you should immediately remove the EtO using an emergency
deluge shower.
G. You should not keep food, beverages, or smoking materials in
regulated areas where employee exposures are above the permissible
exposure limits.
H. Fire extinguishers and emergency deluge showers for quick
drenching should be readily available, and you should know where they
are and how to operate them.
I. Ask your supervisor where EtO is used in your work area and for
any additional plant safety and health rules.
vi. Access to Information
A. Each year, your employer is required to inform you of the
information contained in this standard and appendices for EtO. In
addition, your employer must instruct you in the proper work practices
for using EtO emergency procedures, and the correct use of protective
equipment.
B. Your employer is required to determine whether you are being
exposed to EtO. You or your representative has the right to observe
employee measurements and to record the results obtained. Your employer
is required to inform you of your exposure. If your employer determine
that you are being overexposed, he or she is required to inform you of
the actions which are being taken to reduce your exposure to within
permissible exposure limits.
C. Your employer is required to keep records of your exposures and
medical examinations. These exposure records must be kept by the
employer for at least thirty (30) years. Medical records must be kept
for the period of your employment plus thirty (30) years.
D. Your employer is required to release your exposure and medical
records to your physician or designated representative upon your written
request.
vii. Sterilant Use of Eto in Hospitals and Health Care Facilities
This section of Appendix A, for informational purposes, sets forth
EPA's recommendations for modifications in workplace design and practice
in hospitals and health care facilities for which the Environmental
Protection Agency has registered EtO for uses as a sterilant or fumigant
under the Federal Insecticide, Funigicide, and Rodenticide Act, 7 U.S.C.
136 et seq. These new recommendations, published in the Federal Register
by EPA at 49 FR 15268, as modified in today's Register, are intended to
help reduce the exposure of hospital and health care workers to EtO to 1
ppm. EPA's recommended workplace design and workplace practice are as
follows:
1. Workplace Design
a. Installation of gas line hand valves. Hand valves must be
installed on the gas supply line at the connection to the supply
cylinders to minimize leakage during cylinder change.
b. Installation of capture boxes. Sterilizer operations result in a
gas/water discharge at the completion of the process. This discharge is
routinely piped to a floor drain which is generally located in an
equipment or an adjacent room. When the floor drain is not in the same
room as the sterilizer and workers are not normally present, all that is
necessary is that the room be well ventilated.
The installation of a ``capture box'' will be required for those
work place layouts where the floor drain is located in the same room as
the sterilizer or in a room where workers are normally present. A
``capture box'' is a piece of equipment that totally encloses the floor
drain where the discharge from the sterilizer is pumped. The ``capture
box'' is to be vented directly to a non-recirculating or dedicated
ventilation system. Sufficient air intake should be allowed at the
bottom of the box to handle the volume of air that is ventilated from
the top of the box. The
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``capture box'' can be made of metal, plastic, wood or other equivalent
material. The box is intended to reduce levels of EtO discharged into
the work room atmosphere. The use of a ``capture box'' is not required
if: (1) The vacuum pump discharge floor drain is located in a well
ventilated equipment or other room where workers are not normally
present or (2) the water sealed vacuum pump discharges directly to a
closed sealed sewer line (check local plumbing codes).
If it is impractical to install a vented ``capture box'' and a well
ventilated equipment or other room is not feasible, a box that can be
sealed over the floor drain may be used if: (1) The floor drain is
located in a room where workers are not normally present and EtO cannot
leak into an occupied area, and (2) the sterilizer in use is less than
12 cubic feet in capacity (check local plumbing codes).
c. Ventilation of aeration units i. Existing aeration units.
Existing units must be vented to a non-recirculating or dedicated system
or vented to an equipment or other room where workers are not normally
present and which is well ventilated. Aerator units must be positioned
as close as possible to the sterilizer to minimize the exposure from the
off-gassing of sterilized items.
ii. Installation of new aerator units (where none exist). New
aerator units must be vented as described above for existing aerators.
Aerators must be in place by July 1, 1986.
d. Ventilation during cylinder change. Workers may be exposed to
short but relatively high levels of EtO during the change of gas
cylinders. To reduce exposure from this route, users must select one of
three alternatives designed to draw off gas that may be released when
the line from the sterilizer to the cylinder is disconnected:
i. Location of cylinders in a well ventilated equipment room or
other room where workers are not normally present.
ii. Installation of a flexible hose (at least 4 in
diameter) to a non-recirculating or dedicated ventilation system and
located in the area of cylinder change in such a way that the hose can
be positioned at the point where the sterilizer gas line is disconnected
from the cylinder.
iii. Installation of a hood that is part of a non-recirculating or
dedicated system and positioned no more than one foot above the point
where the change of cylinders takes place.
e. Ventilation of sterilizer door area. One of the major sources of
exposure to EtO occurs when the sterilizer door is opened following the
completion of the sterilization process. In order to reduce this avenue
of exposure, a hood or metal canopy closed on each end must be installed
over the sterilizer door. The hood or metal canopy must be connected to
a non-recirculating or dedicated ventilation system or one that exhausts
gases to a well ventilated equipment or other room where workers are not
normally present. A hood or canopy over the sterilizer door is required
for use even with those sterilizers that have a purge cycle and must be
in place by July 1, 1986.
f. Ventilation of sterilizer relief valve. Sterilizers are typically
equipped with a safety relief device to release gas in case of increased
pressure in the sterilizer. Generally, such relief devices are used on
pressure vessels. Although these pressure relief devices are rarely
opened for hospital and health care sterilizers, it is suggested that
they be designed to exhaust vapor from the sterilizer by one of the
following methods:
i. Through a pipe connected to the outlet of the relief valve
ventilated directly outdoors at a point high enough to be away from
passers by, and not near any windows that open, or near any air
conditioning or ventilation air intakes.
ii. Through a connection to an existing or new non-recirculating or
dedicated ventilation system.
iii. Through a connection to a well ventilated equipment or other
room where workers are not normally present.
g. Ventilation systems. Each hospital and health care facility
affected by this notice that uses EtO for the sterilization of equipment
and supplies must have a ventilation system which enables compliance
with the requirements of section (b) through (f) in the manner described
in these sections and within the timeframes allowed. Thus, each affected
hospital and health care facility must have or install a non-
recirculating or dedicated ventilation equipment or other room where
workers are not normally present in which to vent EtO.
h. Installation of alarm systems. An audible and visual indicator
alarm system must be installed to alert personnel of ventilation system
failures, i.e., when the ventilation fan motor is not working.
2. Workplace Practices
All the workplace practices discussed in this unit must be
permanently posted near the door of each sterilizer prior to use by any
operator.
a. Changing of supply line filters. Filters in the sterilizer liquid
line must be changed when necessary, by the following procedure:
i. Close the cylinder valve and the hose valve.
ii. Disconnect the cylinder hose (piping) from the cylinder.
iii. Open the hose valve and bleed slowly into a proper ventilating
system at or near the in-use supply cylinders.
iv. Vacate the area until the line is empty.
v. Change the filter.
vi. Reconnect the lines and reverse the value position.
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vii. Check hoses, filters, and valves for leaks with a fluorocarbon
leak detector (for those sterilizers using the 88 percent
chlorofluorocarbon, 12 percent ethylene oxide mixture (12/88)).
b. Restricted access area. i. Areas involving use of EtO must be
designated as restricted access areas. They must be identified with
signs or floor marks near the sterilizer door, aerator, vacuum pump
floor drain discharge, and in-use cylinder storage.
ii. All personnel must be excluded from the restricted area when
certain operations are in progress, such as discharging a vacuum pump,
emptying a sterilizer liquid line, or venting a non-purge sterilizer
with the door ajar or other operations where EtO might be released
directly into the face of workers.
c. Door opening procedures. i. Sterilizers with purge cycles. A load
treated in a sterilizer equipped with a purge cycle should be removed
immediately upon completion of the cycle (provided no time is lost
opening the door after cycle is completed). If this is not done, the
purge cycle should be repeated before opening door.
ii. Sterilizers without purge cycles. For a load treated in a
sterilizer not equipped with a purge cycle, the sterilizer door must be
ajar 6 for 15 minutes, and then fully opened for at least
another 15 minutes before removing the treated load. The length of time
of the second period should be established by peak monitoring for one
hour after the two 15-minute periods suggested. If the level is above 10
ppm time-weighted average for 8 hours, more time should be added to the
second waiting period (door wide open). However, in no case may the
second period be shortened to less than 15 minutes.
d. Chamber unloading procedures. i. Procedures for unloading the
chamber must include the use of baskets or rolling carts, or baskets and
rolling tables to transfer treated loads quickly, thus avoiding
excessive contact with treated articles, and reducing the duration of
exposures.
ii. If rolling carts are used, they should be pulled not pushed by
the sterilizer operators to avoid offgassing exposure.
e. Maintenance. A written log should be instituted and maintained
documenting the date of each leak detection and any maintenance
procedures undertaken. This is a suggested use practice and is not
required.
i. Leak detection. Sterilizer door gaskets, cylinder and vacuum
piping, hoses, filters, and valves must be checked for leaks under full
pressure with a Fluorocarbon leak detector (for 12/88 systems only)
every two weeks by maintenance personnel. Also, the cylinder piping
connections must be checked after changing cylinders. Particular
attention in leak detection should be given to the automatic solenoid
valves that control the flow of EtO to the sterilizer. Specifically, a
check should be made at the EtO gasline entrance port to the sterilizer,
while the sterilizer door is open and the solenoid valves are in a
closed position.
ii. Maintenance procedures. Sterilizer/areator door gaskets, valves,
and fittings must be replaced when necessary as determined by
maintenance personnel in their bi-weekly checks; in addition, visual
inspection of the door gaskets for cracks, debris, and other foreign
substances should be conducted daily by the operator.
Appendix B to Sec. 1910.1047--Substance Technical Guidelines for
Ethylene Oxide (Non-Mandatory)
i. Physical and Chemical Data
A. Substance identification:
1. Synonyms: dihydrooxirene, dimethylene oxide, EO, 1,2-epoxyethane,
EtO ETO oxacyclopropane, oxane, oxidoethane, alpha/beta-oxidoethane,
oxiran, oxirane.
2. Formula: (C2 H4 O).
3. Molecular weight: 44.06
B. Physical data:
1. Boiling point (760 mm Hg): 10.70 deg.C (51.3 deg.F);
2. Specific gravity (water = 1): 0.87 (at 20 deg.C or 68 deg.F)
3. Vapor density (air = 1): 1.49;
4. Vapor pressure (at 20 deg.C); 1,095 mm Hg;
5. Solubility in water: complete;
6. Appearance and odor: colorless liquid; gas at temperature above
10.7 deg.F or 51.3 deg.C with ether-like odor above 700 ppm.
ii. Fire, Explosion, and Reactivity Hazard Data
A. Fire:
1. Flash point: less than O deg.F (open cup);
2. Stability: decomposes violently at temperatures above 800 deg.F;
3. Flammable limits in air, percent by volume: Lower: 3, Upper: 100;
4. Extinguishing media: Carbon dioxide for small fires, polymer or
alcohol foams for large fires;
5. Special fire fighting procedures: Dilution of ethylene oxide with
23 volumes of water renders it non-flammable;
6. Unusual fire and explosion hazards: Vapors of EtO will burn
without the presence of air or other oxidizers. EtO vapors are heavier
than air and may travel along the ground and be ignited by open flames
or sparks at locations remote from the site at which EtO is being used.
7. For purposes of compliance with the requirements of 29 CFR
1910.106, EtO is classified as a flammable gas. For example, 7,500 ppm,
approximately one-fourth of the lower flammable limit, would be
considered to pose a potential fire and explosion hazard.
8. For purposes of compliance with 29 CFR 1910.155, EtO is
classified as a Class B fire hazard.
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9. For purpose of compliance with 29 CFR 1919.307, locations
classified as hazardous due to the presence of EtO shall be Class I.
B. Reactivity:
1. Conditions contributing to instability: EtO will polymerize
violently if contaminated with aqueous alkalies, amines, mineral acids,
metal chlorides, or metal oxides. Violent decomposition will also occur
at temperatures above 800 deg.F;
2. Incompatabilities: Alkalines and acids;
3. Hazardous decomposition products: Carbon monoxide and carbon
dioxide.
iii. Spill, Leak, and Disposal Procedures
A. If EtO is spilled or leaked, the following steps should be taken:
1. Remove all ignition sources.
2. The area should be evacuated at once and re-entered only after
the area has been thoroughly ventilated and washed down with water.
B. Persons not wearing appropriate protective equipment should be
restricted from areas of spills or leaks until cleanup has been
completed.
C. Waste disposal methods: Waste material should be disposed of in a
manner that is not hazardous to employees or to the general population.
In selecting the method of waste disposal, applicable local, State, and
Federal regulations should be consulted.
iv. Monitoring and Measurement Procedures
A. Exposure above the Permissible Exposure Limit:
1. Eight-hour exposure evaluation: Measurements taken for the
purpose of determining employee exposure under this section are best
taken with consecutive samples covering the full shift. Air samples
should be taken in the employee's breathing zone (air that would most
nearly represent that inhaled by the employee.)
2. Monitoring techniques: The sampling and analysis under this
section may be performed by collection of the EtO vapor on charcoal
adsorption tubes or other composition adsorption tubes, with subsequent
chemical analysis. Sampling and analysis may also be performed by
instruments such as real-time continuous monitoring systems, portable
direct reading instruments, or passive dosimeters as long as
measurements taken using these methods accurately evaluate the
concentration of EtO in employees' breathing zones.
Appendix D describes the validated method of sampling and analysis
which has been tested by OSHA for use with EtO. Other available methods
are also described in Appendix D. The employer has the obligation of
selecting a monitoring method which meets the accuracy and precision
requirements of the standard under his unique field conditions. The
standard requires that the method of monitoring should be accurate, to a
95 percent confidence level, to plus or minus 25 percent for
concentrations of EtO at 1 ppm, and to plus or minus 35 percent for
concentrations at 0.5 ppm. In addition to the method described in
Appendix D, there are numerous other methods available for monitoring
for EtO in the workplace. Details on these other methods have been
submitted by various companies to the rulemaking record, and are
available at the OSHA Docket Office.
B. Since many of the duties relating to employee exposure are
dependent on the results of measurement procedures, employers should
assure that the evaluation of employee exposures is performed by a
technically qualified person.
v. Protective Clothing and Equipment
Employees should be provided with and be required to wear
appropriate protective clothing wherever there is significant potential
for skin contact with liquid EtO or EtO-containing solutions. Protective
clothing shall include impermeable coveralls or similar full-body work
clothing, gloves, and head coverings, as appropriate to protect areas of
the body which may come in contact with liquid EtO or EtO-containing
solutions.
Employers should ascertain that the protective garments are
impermeable to EtO. Permeable clothing, including items made of rubber,
and leather shoes should not be allowed to become contaminated with
liquid EtO. If permeable clothing does become contaminated, it should be
immediately removed, while the employer is under an emergency deluge
shower. If leather footwear or other leather garments become wet from
EtO they should be discarded and not be worn again, because leather
absorbs EtO and holds it against the skin.
Any protective clothing that has been damaged or is otherwise found
to be defective should be repaired or replaced. Clean protective
clothing should be provided to the employee as necessary to assure
employee protection. Whenever impermeable clothing becomes wet with
liquid EtO, it should be washed down with water before being removed by
the employee. Employees are also required to wear splash-proof safety
goggles where there is any possibility of EtO contacting the eyes.
vi. Miscellaneous Precautions
A. Store EtO in tightly closed containers in a cool, well-ventilated
area and take all necessary precautions to avoid any explosion hazard.
B. Non-sparking tools must be used to open and close metal
containers. These containers must be effectively grounded and bonded.
C. Do not incinerate EtO cartridges, tanks or other containers.
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D. Employers should advise employees of all areas and operations
where exposure to EtO occur.
vii. Common Operations
Common operations in which exposure to EtO is likely to occur
include the following: Manufacture of EtO, surfactants, ethanolamines,
glycol ethers, and specialty chemicals, and use as a sterilant in the
hospital, health product and spice industries.
Appendix C to Sec. 1910.1047--Medical Surveillance Guidelines for
Ethylene Oxide (Non-Mandatory)
i. route of entry
Inhalation.
ii. toxicology
Clinical evidence of adverse effects associated with the exposure to
EtO is present in the form of increased incidence of cancer in
laboratory animals (leukemia, stomach, brain), mutation in offspring in
animals, and resorptions and spontaneous abortions in animals and human
populations respectively. Findings in humans and experimental animals
exposed to airborne concentrations of EtO also indicate damage to the
genetic material (DNA). These include hemoglobin alkylation,
unsecheduled DNA synthesis, sister chromatid exchange chromosomal
aberration, and functional sperm abnormalities.
Ethylene oxide in liquid form can cause eye irritation and injury to
the cornea, frostbite, severe irritation, and blistering of the skin
upon prolonged or confined contact. Ingestion of EtO can cause gastric
irritation and liver injury. Other effects from inhalation of EtO vapors
include respiratory irritation and lung injury, headache, nausea,
vomiting, diarrhea, dyspnea and cyanosis.
iii. signs and symptoms of acute overexposure
The early effects of acute overexposure to EtO are nausea and
vomiting, headache, and irritation of the eyes and respiratory passages.
The patient may notice a ``peculiar taste'' in the mouth. Delayed
effects can include pulmonary edema, drowsiness, weakness, and
incoordination. Studies suggest that blood cell changes, an increase in
chromosomal aberrations, and spontaneous abortion may also be causally
related to acute overexposure to EtO.
Skin contact with liquid or gaseous EtO causes characteristic burns
and possibly even an allergic-type sensitization. The edema and erythema
occurring from skin contact with EtO progress to vesiculation with a
tendency to coalesce into blebs with desquamation. Healing occurs within
three weeks, but there may be a residual brown pigmentation. A 40-80%
solution is extremely dangerous, causing extensive blistering after only
brief contact. Pure liquid EtO causes frostbite because of rapid
evaporation. In contrast, the eye is relatively insensitive to EtO, but
there may be some irritation of the cornea.
Most reported acute effects of occupational exposure to EtO are due
to contact with EtO in liquid phase. The liquid readily penetrates
rubber and leather, and will produce blistering if clothing or footwear
contaminated with EtO are not removed.
iv. surveillance and preventive considerations
As noted above, exposure to EtO has been linked to an increased risk
of cancer and reproductive effects including decreased male fertility,
fetotoxicity, and spontaneous abortion. EtO workers are more likely to
have chromosomal damage than similar groups not exposed to EtO. At the
present, limited studies of chronic effects in humans resulting from
exposure to EtO suggest a causal association with leukemia. Animal
studies indicate leukemia and cancers at other sites (brain, stomach) as
well. The physician should be aware of the findings of these studies in
evaluating the health of employees exposed to EtO.
Adequate screening tests to determine an employee's potential for
developing serious chronic diseases, such as cancer, from exposure to
EtO do not presently exist. Laboratory tests may, however, give evidence
to suggest that an employee is potentially overexposed to EtO. It is
important for the physician to become familiar with the operating
conditions in which exposure to EtO is likely to occur. The physician
also must become familiar with the signs and symptoms that indicate a
worker is receiving otherwise unrecognized and unacceptable exposure to
EtO. These elements are especially important in evaluating the medical
and work histories and in conducting the physical exam. When an
unacceptable exposure in an active employee is identified by the
physician, measures taken by the employer to lower exposure should also
lower the risk of serious long-term consequences.
The employer is required to institute a medical surveillance program
for all employees who are or will be exposed to EtO at or above the
action level (0.5 ppm) for at least 30 days per year, without regard to
respirator use. All examinations and procedures must be performed by or
under the supervision of a licensed physician at a reasonable time and
place for the employee and at no cost to the employee.
Although broad latitude in prescribing specific tests to be included
in the medical surveillance program is extended to the examining
physician, OSHA requires inclusion of the following elements in the
routine examination:
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(i) Medical and work histories with special emphasis directed to
symptoms related to the pulmonary, hematologic, neurologic, and
reproductive systems and to the eyes and skin.
(ii) Physical examination with particular emphasis given to the
pulmonary, hematologic, neurologic, and reproductive systems and to the
eyes and skin.
(iii) Complete blood count to include at least a white cell count
(including differential cell count), red cell count, hematocrit, and
hemoglobin.
(iv) Any laboratory or other test which the examining physician
deems necessary by sound medical practice.
If requested by the employee, the medical examinations shall include
pregnancy testing or laboratory evaluation of fertility as deemed
appropriate by the physician.
In certain cases, to provide sound medical advice to the employer
and the employee, the physician must evaluate situations not directly
related to EtO. For example, employees with skin diseases may be unable
to tolerate wearing protective clothing. In addition those with chronic
respiratory diseases may not tolerate the wearing of negative pressure
(air purifying) respirators. Additional tests and procedures that will
help the physician determine which employees are medically unable to
wear such respirators should include: An evaluation of cardiovascular
function, a baseline chest x-ray to be repeated at five year intervals,
and a pulmonary function test to be repeated every three years. The
pulmonary function test should include measurement of the employee's
forced vital capacity (FVC), forced expiratory volume at one second
(FEV1), as well as calculation of the ratios of FEV1 to FVC, and
measured FVC and measured FEV1 to expected values corrected for
variation due to age, sex, race, and height.
The employer is required to make the prescribed tests available at
least annually to employees who are or will be exposed at or above the
action level, for 30 or more days per year; more often than specified if
recommended by the examining physician; and upon the employee's
termination of employment or reassignment to another work area. While
little is known about the long term consequences of high short-term
exposures, it appears prudent to monitor such affected employees closely
in light of existing health data. The employer shall provide physician
recommended examinations to any employee exposed to EtO in emergency
conditions. Likewise, the employer shall make available medical
consultations including physician recommended exams to employees who
believe they are suffering signs or symptoms of exposure to EtO.
The employer is required to provide the physician with the following
informatin: a copy of this standard and its appendices; a description of
the affected employee's duties as they relate to the employee exposure
level; and information from the employee's previous medical examinations
which is not readily available to the examining physician. Making this
information available to the physician will aid in the evaluation of the
employee's health in relation to assigned duties and fitness to wear
personal protective equipment, when required.
The employer is required to obtain a written opinion from the
examining physician containing the results of the medical examinations;
the physician's opinion as to whether the employee has any detected
medical conditions which would place the employee at increased risk of
material impairment of his or her health from exposure to EtO; any
recommended restrictions upon the employee's exposure to EtO, or upon
the use of protective clothing or equipment such as respirators; and a
statement that the employee has been informed by the physician of the
results of the medical examination and of any medical conditions which
require further explanation or treatment. This written opinion must not
reveal specific findings or diagnoses unrelated to occupational exposure
to EtO, and a copy of the opinion must be provided to the affected
employee.
The purpose in requiring the examining physician to supply the
employer with a written opinion is to provide the employer with a
medical basis to aid in the determination of initial placement of
employees and to assess the employee's ability to use protective
clothing and equipment.
Appendix D to Sec. 1910.1047--Sampling and Analytical Methods for
Ethylene Oxide (Non-Mandatory)
A number of methods are available for monitoring employee exposures
to EtO. Most of these involve the use of charcoal tubes and sampling
pumps, followed by analysis of the samples by gas chromatograph. The
essential differences between the charcoal tube methods include, among
others, the use of different desorbing solvents, the use of different
lots of charcoal, and the use of different equipment for analysis of the
samples.
Besides charcoal, methods using passive dosimeters, gas sampling
bags, impingers, and detector tubes have been utilized for determination
of EtO exposure. In addition, there are several commercially available
portable gas analyzers and monitoring units.
This appendix contains details for the method which has been tested
at the OSHA Analytical Laboratory in Salt Lake City. Inclusion of this
method in the appendix does not mean that this method is the only one
which will be satisfactory. Copies of descriptions of other methods
available are available in the rulemaking record, and may be obtained
from the OSHA Docket Office.
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These include the Union Carbide, Dow Chemical, 3M, and DuPont methods,
as well as NIOSH Method S-286. These methods are briefly described at
the end of this appendix.
Employers who note problems with sample breakthrough using the OSHA
or other charcoal methods should try larger charcoal tubes. Tubes of
larger capacity are available. In addition, lower flow rates and shorter
sampling times should be beneficial in minimizing breakthrough problems.
Whatever method the employer chooses, he must assure himself of the
method's accuracy and precision under the unique conditions present in
his workplace.
Ethylene Oxide
Method No.: 30.
Matrix: Air.
Target Concentration: 1.0 ppm (1.8 mg/m3).
Procedure: Samples are collected on two charcoal tubes in series and
desorbed with 1% CS2 in benzene. The samples are derivatized
with HBr and treated with sodium carbonate. Analysis is done by gas
chromatography with an electron capture detector.
Recommended Air Volume and Sampling Rate: 1 liter and 0.05 Lpm.
Detection Limit of the Overall Procedure: 13.3 ppb (0.024 mg/
m3) (Based on 1.0 liter air sample).
Reliable Quantitation Limit: 52.2 ppb (0.094 mg/m3)
(Based on 1.0 liter air sample).
Standard Error of Estimate: 6.59% (See Backup Section 4.6).
Special Requirements: Samples must be analyzed within 15 days of
sampling date.
Status of Method: The sampling and analytical method has been
subjected to the established evaluation procedures of the Organic Method
Evaluations Branch.
Date: August 1981.
Chemist: Wayne D. Potter.
Organic Solvents Branch, OSHA Analytical Laboratory, Salt Lake City,
Utah
1. General Discussion.
1.1 Background.
1.1.1 History of Procedure.
Ethylene oxide samples analyzed at the OSHA Laboratory have normally
been collected on activated charcoal and desorbed with carbon disulfide.
The analysis is performed with a gas chromatograph equipped with a FID
(Flame ionization detector) as described in NIOSH Method S286 (Ref.
5.1). This method is based on a PEL of 50 ppm and has a detection limit
of about 1 ppm.
Recent studies have prompted the need for a method to analyze and
detect ethylene oxide at very low concentrations.
Several attempts were made to form an ultraviolet (UV) sensitive
derivative with ethylene oxide for analysis with HPLC. Among those
tested that gave no detectable product were: p-anisidine,
methylimidazole, aniline, and 2,3,6-trichlorobenzoic acid. Each was
tested with catalysts such as triethylamine, aluminum chloride,
methylene chloride and sulfuric acid but no detectable derivative was
produced.
The next derivatization attempt was to react ethylene oxide with HBr
to form 2-bromoethanol. This reaction was successful. An ECD (electron
capture detector) gave a very good response for 2-bromoethanol due to
the presence of bromine. The use of carbon disulfide as the desorbing
solvent gave too large a response and masked the 2-bromoethanol. Several
other solvents were tested for both their response on the ECD and their
ability to desorb ethylene oxide from the charcoal. Among those tested
were toluene, xylene, ethyl benzene, hexane, cyclohexane and benzene.
Benzene was the only solvent tested that gave a suitable response on the
ECD and a high desorption. It was found that the desorption efficiency
was improved by using 1% CS2 with the benzene. The carbon
disulfide did not significantly improve the recovery with the other
solvents. SKC Lot 120 was used in all tests done with activated
charcoal.
1.1.2 Physical Properties (Ref. 5.2-5.4).
Synonyms: Oxirane; dimethylene oxide, 1,2-epoxy-ethane; oxane;
C2 H4 O; ETO;
Molecular Weight: 44.06
Boiling Point: 10.7 deg.C (51.3 deg.)
Melting Point: -111 deg.C
Description: Colorless, flammable gas
Vapor Pressure: 1095 mm. at 20 deg.C
Odor: Ether-like odor
Lower Explosive Limits: 3.0% (by volume)
Flash Point (TOC): Below 0 deg.F
Molecular Structure: CH 2--CH 2
1.2 Limit Defining Parameters.
1.2.1 Detection Limit of the Analytical Procedure.
The detection limit of the analytical procedure is 12.0 picograms of
ethylene oxide per injection. This is the amount of analyte which will
give a peak whose height is five times the height of the baseline noise.
(See Backup Data Section 4.1).
1.2.2 Detection Limit of the Overall Procedure.
The detection limit of the overall procedure is 24.0 ng of ethylene
oxide per sample.
This is the amount of analyte spiked on the sampling device which
allows recovery of an amount of analyte equivalent to the detection
limit of the analytical procedure. (See Backup Data Section 4.2).
1.2.3 Reliable Quantitation Limit.
The reliable quantitation limit is 94.0 nanograms of ethylene oxide
per sample. This is the smallest amount of analyte which can be
quantitated within the requirements of 75% recovery and 95% confidence
limits. (See Backup Data Section 4.2).
[[Page 349]]
It must be recognized that the reliable quantitation limit and
detection limits reported in the method are based upon optimization of
the instrument for the smallest possible amount of analyte. When the
target concentration of an analyte is exceptionally higher than these
limits, they may not be attainable at the routine operating parameters.
In this case, the limits reported on analysis reports will be based on
the operating parameters used during the analysis of the samples.
1.2.4 Sensitivity.
The sensitivity of the analytical procedure over a concentration
range representing 0.5 to 2 times the target concentration based on the
recommended air volume is 34105 area units per [mu]g/mL. The sensitivity
is determined by the slope of the calibration curve (See Backup Data
Section 4.3).
The sensitivity will vary somewhat with the particular instrument
used in the analysis.
1.2.5 Recovery.
The recovery of analyte from the collection medium must be 75% or
greater. The average recovery from spiked samples over the range of 0.5
to 2 times the target concentration is 88.0% (See Backup Section 4.4).
At lower concentrations the recovery appears to be non-linear.
1.2.6 Precision (Analytical Method Only).
The pooled coefficient of variation obtained from replicate
determination of analytical standards at 0.5X, 1X and 2X the target
concentration is 0.036 (See Backup Data Section 4.5).
1.2.7 Precision (Overall Procedure).
The overall procedure must provide results at the target
concentration that are 25% of better at the 95% confidence level. The
precision at the 95% confidence level for the 15 day storage test is
plus or minus 12.9% (See Backup Data Section 4.6).
This includes an additional plus or minus 5% for sampling error.
1.3 Advantages.
1.3.1 The sampling procedure is convenient.
1.3.2 The analytical procedure is very sensitive and reproducible.
1.3.3 Reanalysis of samples is possible.
1.3.4 Samples are stable for at least 15 days at room temperature.
1.3.5 Interferences are reduced by the longer GC retention time of
the new derivative.
1.4 Disadvantages.
1.4.1 Two tubes in series must be used because of possible
breakthrough and migration.
1.4.2 The precision of the sampling rate may be limited by the
reproducibility of the pressure drop across the tubes. The pumps are
usually calibrated for one tube only.
1.4.3 The use of benzene as the desorption solvent increases the
hazards of analysis because of the potential carcinogenic effects of
benzene.
1.4.4 After repeated injections there can be a buildup of residue
formed on the electron capture detector which decreases sensitivity.
1.4.5 Recovery from the charcoal tubes appears to be nonlinear at
low concentrations.
2. Sampling Procedure.
2.1 Apparatus.
2.1.1 A calibrated personal sampling pump whose flow can be
determined within plus or minus 5% of the recommended flow.
2.1.2 SKC Lot 120 Charcoal tubes: glass tube with both ends flame
sealed, 7 cm long with a 6 mm O.D. and a 4-mm I.D., containing 2
sections of coconut shell charcoal separated by a 2-mm portion of
urethane foam. The adsorbing section contains 100 mg of charcoal, the
backup section 50 mg. A 3-mm portion of urethane foam is placed between
the outlet end of the tube and the backup section. A plug of silylated
glass wool is placed in front of the adsorbing section.
2.2 Reagents.
2.2.1 None required.
2.3 Sampling Technique.
2.3.1 Immediately before sampling, break the ends of the charcoal
tubes. All tubes must be from the same lot.
2.3.2 Connect two tubes in series to the sampling pump with a short
section of flexible tubing. A minimum amount of tubing is used to
connect the two sampling tubes together. The tube closer to the pump is
used as a backup. This tube should be identified as the backup tube.
2.3.3 The tubes should be placed in a vertical position during
sampling to minimize channeling.
2.3.4 Air being sampled should not pass through any hose or tubing
before entering the charcoal tubes.
2.3.5 Seal the charcoal tubes with plastic caps immediately after
sampling. Also, seal each sample with OSHA seals lengthwise.
2.3.6 With each batch of samples, submit at least one blank tube
from the same lot used for samples. This tube should be subjected to
exactly the same handling as the samples (break, seal, transport) except
that no air is drawn through it.
2.3.7 Transport the samples (and corresponding paperwork) to the
lab for analysis.
2.3.8 If bulk samples are submitted for analysis, they shoud be
transported in glass containers with Teflon-lined caps. These samples
must be mailed separately from the container used for the charcoal
tubes.
2.4 Breakthrough.
2.4.1 The breakthrough (5% breakthrough) volume for a 3.0 mg/m
ethylene oxide sample stream at approximately 85% relative humidity, 22
deg.C and 633 mm is 2.6 liters sampled at 0.05 liters per minute. This
is equivalent
[[Page 350]]
to 7.8 [mu] g of ethylene oxide. Upon saturation of the tube it appeared
that the water may be displacing ethylene oxide during sampling.
2.5 Desorption Efficiency.
2.5.1 The desorption efficiency, from liquid injection onto
charcoal tubes, averaged 88.0% from 0.5 to 2.0 x the target
concentration for a 1.0 liter air sample. At lower ranges it appears
that the desorption efficiency is non-linear (See Backup Data Section
4.2).
2.5.2 The desorption efficiency may vary from one laboratory to
another and also from one lot of charcoal to another. Thus, it is
necessary to determine the desorption efficiency for a particular lot of
charcoal.
2.6 Recommended Air Volume and Sampling Rate.
2.6.1 The recommended air volume is 1.0 liter.
2.6.2 The recommended maximum sampling rate is 0.05 Lpm.
2.7 Interferences.
2.7.1 Ethylene glycol and Freon 12 at target concentration levels
did not interfere with the collection of ethylene oxide.
2.7.2 Suspected interferences should be listed on the sample data
sheets.
2.7.3 The relative humidity may affect the sampling procedure.
2.8 Safety Precautions.
2.8.1 Attach the sampling equipment to the employee so that it does
not interfere with work performance.
2.8.2 Wear safety glasses when breaking the ends of the sampling
tubes.
2.8.3 If possible, place the sampling tubes in a holder so the
sharp end is not exposed while sampling.
3. Analytical Method.
3.1 Apparatus.
3.1.1 Gas chromatograph equipped with a linearized electron capture
detector.
3.1.2 GC column capable of separating the derivative of ethylene
oxide (2-bromoethanol) from any interferences and the 1% CS2
in benzene solvent. The column used for validation studies was: 10 ft x
\1/8\ inch stainless steel 20% SP-2100, .1% Carbowax 1500 on 100/120
Supelcoport.
3.1.3 An electronic integrator or some other suitable method of
measuring peak areas.
3.1.4 Two milliliter vials with Teflon-lined caps.
3.1.5 Gas tight syringe--500 [mu] L or other convenient sizes for
preparing standards.
3.1.6 Microliter syringes--10 [mu] L or other convenient sizes for
diluting standards and 1 [mu] L for sample injections.
3.1.7 Pipets for dispensing the 1% CS2 in benzene
solvent. The Glenco 1 mL dispenser is adequate and convenient.
3.1.8 Volumetric flasks--5 mL and other convenient sizes for
preparing standards.
3.1.9 Disposable Pasteur pipets.
3.2 Reagents.
3.2.1 Benzene, reagent grade.
3.2.2 Carbon Disulfide, reagent grade.
3.2.3 Ethylene oxide, 99.7% pure.
3.2.4 Hydrobromic Acid, 48% reagent grade.
3.2.5 Sodium Carbonate, anhydrous, reagent grade.
3.2.6 Desorbing reagent, 99% Benzene/1% CS2.
3.3 Sample Preparation.
3.3.1 The front and back sections of each sample are transferred to
separate 2-mL vials.
3.3.2 Each sample is desorbed with 1.0 mL of desorbing reagent.
3.3.3 The vials are sealed immediately and allowed to desorb for
one hour with occasional shaking.
3.3.4 Desorbing reagent is drawn off the charcoal with a disposable
pipet and put into clean 2-mL vials.
3.3.5 One drop of HBr is added to each vial. Vials are resealed and
HBr is mixed well with the desorbing reagent.
3.3.6 About 0.15 gram of sodium carbonate is carefully added to
each vial. Vials are again resealed and mixed well.
3.4 Standard Preparation.
3.4.1 Standards are prepared by injecting the pure ethylene oxide
gas into the desorbing reagent.
3.4.2 A range of standards are prepared to make a calibration
curve. A concentration of 1.0 [mu] L of ethylene oxide gas per 1 mL
desorbing reagent is equivalent to 1.0 ppm air concentration (all gas
volumes at 25 deg.C and 760 mm) for the recommended 1 liter air sample.
This amount is uncorrected for desorption efficiency (See Backup Data
Section 4.2. for desorption efficiency corrections).
3.4.3 One drop of HBr per mL of standard is added and mixed well.
3.4.4 About 0.15 grams of sodium carbonate is carefully added for
each drop of HBr (A small reaction will occur).
3.5 Analysis.
3.5.1 GC Conditions.
Nitrogen flow rate--10mL/min.
Injector Temperature--250 deg.C
Detector Temperature--300 deg.C
Column Temperature--100 deg.C
Injection size--0.8 [mu] L
Elution time--3.9 minutes
3.5.2 Peak areas are measured by an integrator or other suitable
means.
3.5.3 The integrator results are in area units and a calibration
curve is set up with concentration vs. area units.
3.6 Interferences.
3.6.1 Any compound having the same retention time of 2-bromoethanol
is a potential interference. Possible interferences should be listed on
the sample data sheets.
3.6.2 GC parameters may be changed to circumvent interferences.
[[Page 351]]
3.6.3 There are usually trace contaminants in benzene. These
contaminants, however, posed no problem of interference.
3.6.4 Retention time data on a single column is not considered
proof of chemical identity. Samples over the 1.0 ppm target level should
be confirmed by GC/Mass Spec or other suitable means.
3.7 Calculations
3.7.1 The concentration in [mu]g/mL for a sample is determined by
comparing the area of a particular sample to the calibration curve,
which has been prepared from analytical standards.
3.7.2 The amount of analyte in each sample is corrected for
desorption efficiency by use of a desorption curve.
3.7.3 Analytical results (A) from the two tubes that compose a
particular air sample are added together.
3.7.4 The concentration for a sample is calculated by the following
equation:
[GRAPHIC] [TIFF OMITTED] TC15NO91.038
where:
A=[mu]g/mL
B=desorption volume in milliliters
C=air volume in liters.
3.7.5 To convert mg/m3 to parts per million (ppm) the
following relationship is used:
[GRAPHIC] [TIFF OMITTED] TC15NO91.039
where:
mg/m3=results from 3.7.4
24.45=molar volume at 25 deg.C and 760mm Hg
44.05=molecular weight of ETO.
3.8 Safety Precautions
3.8.1 Ethylene oxide and benzene are potential carcinogens and care
must be exercised when working with these compounds.
3.8.2 All work done with the solvents (preparation of standards,
desorption of samples, etc.) should be done in a hood.
3.8.3 Avoid any skin contact with all of the solvents.
3.8.4 Wear safety glasses at all times.
3.8.5 Avoid skin contact with HBr because it is highly toxic and a
strong irritant to eyes and skin.
4. Backup Data.
4.1 Detection Limit Data.
The detection limit was determined by injecting 0.8 [mu]L of a 0.015
[mu]g/mL standard of ethylene oxide into 1% CS2 in benzene.
The detection limit of the analytical procedure is taken to be
1.20x10-5 [mu]g per injection. This is equivalent to 8.3 ppb
(0.015 mg/m3) for the recommended air volume.
4.2 Desorption Efficiency.
Ethylene oxide was spiked onto charcoal tubes and the following
recovery data was obtained.
------------------------------------------------------------------------
Amount recovered
Amount spiked ([mu]g) ([mu]g) Percent recovery
------------------------------------------------------------------------
4.5 4.32 96.0
3.0 2.61 87.0
2.25 2.025 90.0
1.5 1.365 91.0
1.5 1.38 92.0
.75 .6525 87.0
.375 .315 84.0
.375 .312 83.2
.1875 .151 80.5
.094 .070 74.5
------------------------------------------------------------------------
At lower amounts the recovery appears to be non-linear.
4.3 Sensitivity Data.
The following data was used to determine the calibration curve.
----------------------------------------------------------------------------------------------------------------
0.5x.75 [mu]g/
Injection mL 1x1.5 [mu]g/mL 2x3.0 [mu]g/mL
----------------------------------------------------------------------------------------------------------------
1............................................................... 30904 59567 111778
2............................................................... 30987 62914 106016
3............................................................... 32555 58578 106122
4............................................................... 32242 57173 109716
X............................................................... 31672 59558 108408
----------------------------------------------------------------------------------------------------------------
Slope=34.105.
4.4 Recovery.
The recovery was determined by spiking ethylene oxide onto lot 120
charcoal tubes and desorbing with 1% CS2 in Benzene.
Recoveries were done at 0.5, 1.0, and 2.0 X the target concentration (1
ppm) for the recommended air volume.
Percent Recovery
------------------------------------------------------------------------
Sample 0.5x 1.0x 2.0x
------------------------------------------------------------------------
1...................................... 88.7 95.0 91.7
2...................................... 83.8 95.0 87.3
3...................................... 84.2 91.0 86.0
4...................................... 88.0 91.0 83.0
5...................................... 88.0 86.0 85.0
X...................................... 86.5 90.5 87.0
------------------------------------------------------------------------
Weighted Average=88.2.
4.5 Precision of the Analytical Procedure.
The following data was used to determine the precision of the
analytical method:
------------------------------------------------------------------------
0.5x.75 1X1.5 2X3.0
Concentration [mu]g/ [mu]g/ [mu]g/
mL mL mL
------------------------------------------------------------------------
Injection.................................... .7421 1.4899 3.1184
.7441 1.5826 3.0447
.7831 1.4628 2.9149
.7753 1.4244 2.9185
Average...................................... .7612 1.4899 2.9991
Standard Deviation........................... .0211 .0674 .0998
CV........................................... .0277 .0452 .0333
------------------------------------------------------------------------
[GRAPHIC] [TIFF OMITTED] TR24JY03.009
CV+0.036
4.6 Storage Data.
Samples were generated at 1.5 mg/m\3\ ethylene oxide at 85% relative
humidity, 22 deg.C and 633 mm. All samples were taken for 20 minutes at
0.05 Lpm. Six samples were analyzed
[[Page 352]]
as soon as possible and fifteen samples were stored at refrigerated
temperature (5 deg.C) and fifteen samples were stored at ambient
temperature (23 deg.C). These stored samples were analyzed over a
period of nineteen days.
Percent Recovery
------------------------------------------------------------------------
Day analyzed Refrigerated Ambient
------------------------------------------------------------------------
1.............................................. 87.0 87.0
1.............................................. 93.0 93.0
1.............................................. 94.0 94.0
1.............................................. 92.0 92.0
4.............................................. 92.0 91.0
4.............................................. 93.0 88.0
4.............................................. 91.0 89.0
6.............................................. 92.0 .........
6.............................................. 92.0 .........
8.............................................. ............ 92.0
8.............................................. ............ 86.0
10............................................. 91.7 .........
10............................................. 95.5 .........
10............................................. 95.7 .........
11............................................. ............ 90.0
11............................................. ............ 82.0
13............................................. 78.0 .........
13............................................. 81.4 .........
13............................................. 82.4 .........
14............................................. ............ 78.5
14............................................. ............ 72.1
18............................................. 66.0 .........
18............................................. 68.0 .........
19............................................. ............ 64.0
19............................................. ............ 77.0
------------------------------------------------------------------------
4.7 Breakthrough Data.
Breakthrough studies were done at 2 ppm (3.6 mg/m\3\) at
approximately 85% relative humidity at 22 deg.C (ambient temperature).
Two charcoal tubes were used in series. The backup tube was changed
every 10 minutes and analyzed for breakthrough. The flow rate was 0.050
Lpm.
------------------------------------------------------------------------
Time Percent
Tube No. (minutes) breakthrough
------------------------------------------------------------------------
1.............................................. 10 (\1\)
2.............................................. 20 (\1\)
3.............................................. 30 (\1\)
4.............................................. 40 1.23
5.............................................. 50 3.46
6.............................................. 60 18.71
7.............................................. 70 39.2
8.............................................. 80 53.3
9.............................................. 90 72.0
10............................................. 100 96.0
11............................................. 110 113.0
12............................................. 120 133.9
------------------------------------------------------------------------
\1\ None.
The 5% breakthrough volume was reached when 2.6 liters of test
atmosphere were drawn through the charcoal tubes.
5. References.
5.1 ``NIOSH Manual of Analytical Methods,'' 2nd ed. NIOSH:
Cincinnati, 1977; Method S286.
5.2 ``IARC Monographs on the Evaluation of Carcinogenic Risk of
Chemicals to Man,'' International Agency for Research on Cancer: Lyon,
1976; Vol. II, p. 157.
5.3 Sax., N.I. ``Dangerous Properties of Industrial Materials,''
4th ed.; Van Nostrand Reinhold Company. New York, 1975; p. 741.
5.4 ``The Condensed Chemical Dictionary'', 9th ed.; Hawley, G.G.,
ed.; Van Nostrand Reinhold Company, New York, 1977; p. 361.
Summary of Other Sampling Procedures
OSHA believes that served other types of monitoring equipment and
techniques exist for monitoring time-weighted averages. Considerable
research and method development is currently being performed, which will
lead to improvements and a wider variety of monitoring techniques. A
combination of monitoring procedures can be used. There probably is no
one best method for monitoring personal exposure to ethylene oxide in
all cases. There are advantages, disadvantages, and limitations to each
method. The method of choice will depend on the need and requirements.
Some commonly used methods include the use of charcoal tubes, passive
dosimeters, Tedler gas sampling bags, detector tubes, photoionization
detection units, infrared detection units and gas chromatographs. A
number of these methods are described below.
A. Charcoal Tube Sampling Procedures
Qazi-Ketcham method (Ex. 11-133)--This method consists of collecting
EtO on Columbia JXC activated carbon, desorbing the EtO with carbon
disulfide and analyzing by gas chromatography with flame ionization
detection. Union Carbide has recently updated and revalidated this
monitoring procedures. This method is capable of determining both eight-
hour time-weighted average exposures and short-term exposures. The
method was validated to 0.5 ppm. Like other charcoal collecting
procedures, the method requires considerable analytical expertise.
ASTM-proposed method-- The Ethylene Oxide Industry Council (EOIC)
has contracted with Clayton Environmental Consultants, Inc. to conduct a
collaborative study for the proposed method. The ASTM-Proposed method is
similar to the method published by Qazi and Ketcham is the November 1977
American Industrial Hygiene Association Journal, and to the method of
Pilney and Coyne, presented at the 1979 American Industrial Hygiene
Conference. After the air to be sampled is drawn through an activated
charcoal tube, the ethylene oxide is desorbed from the tube using carbon
disulfide and is quantitated by gas chromatography utilizing a flame
ionization detector. The ASTM-proposed method specifies a large two-
section charcoal tube, shipment in dry ice, storage at less
than -5 deg.C, and analysis within three weeks to prevent migration and
sample loss. Two types of charcoal tubes are being tested--
[[Page 353]]
Pittsburgh Coconut-Based (PCB) and Columbia JXC charcoal. This
collaborative study will give an indication of the inter- and
intralaboratory precision and accuracy of the ASTM-proposed method.
Several laboratories have considerable expertise using the Qazi-Ketcham
and Dow methods.
B. Passive Monitors--Ethylene oxide diffuses into the monitor and is
collected in the sampling media. The DuPont Pro-Tek badge collects EtO
in an absorbing solution, which is analyzed colorimetrically to
determine the amount of EtO present. The 3M 350 badge collects the EtO
on chemically treated charcoal. Other passive monitors are currently
being developed and tested. Both 3M and DuPont have submitted data
indicating their dosimeters meet the precision and accuracy requirements
of the proposed ethylene oxide standard. Both presented laboratory
validation data to 0.2 ppm (Exs. 11-65, 4-20, 108, 109, 130).
C. Tedlar Gas Sampling Bags-Samples are collected by drawing a known
volume of air into a Tedlar gas sampling bag. The ethylene oxide
concentration is often determined on-site using a portable gas
chromatograph or portable infrared spectometer.
D. Detector tubes--A known volume of air is drawn through a detector
tube using a small hand pump. The concentration of EtO is related to the
length of stain developed in the tube. Detector tubes are economical,
easy to use, and give an immediate readout. Unfortunately, partly
because they are nonspecific, their accuracy is often questionable.
Since the sample is taken over a short period of time, they may be
useful for determining the source of leaks.
E. Direct Reading Instruments--There are numerous types of direct
reading instruments, each having its own strengths and weaknesses (Exs.
135B, 135C, 107, 11-78, 11-153). Many are relatively new, offering
greater sensitivity and specificity. Popular ethylene oxide direct
reading instruments include infrared detection units, photoionization
detection units, and gas chromatographs.
Portable infrared analyzers provide an immediate, continuous
indication of a concentration value; making them particularly useful for
locating high concentration pockets, in leak detection and in ambient
air monitoring. In infrared detection units, the amount of infrared
light absorbed by the gas being analyzed at selected infrared
wavelengths is related to the concentration of a particular component.
Various models have either fixed or variable infrared filters, differing
cell pathlengths, and microcomputer controls for greater sensitivity,
automation, and interference elimination.
A fairly recent detection system is photoionization detection. The
molecules are ionized by high energy ultraviolet light. The resulting
current is measured. Since different substances have different
ionization potentials, other organic compounds may be ionized. The lower
the lamp energy, the better the selectivity. As a continuous monitor,
photoionization detection can be useful for locating high concentration
pockets, in leak detection, and continuous ambient air monitoring. Both
portable and stationary gas chromatographs are available with various
types of detectors, including photoionization detectors. A gas
chromatograph with a photoionization detector retains the photionization
sensitivity, but minimizes or eliminates interferences. For several GC/
PID units, the sensitivity is in the 0.1-0.2 ppm EtO range. The GC/PID
with microprocessors can sample up to 20 sample points sequentially,
calculate and record data, and activate alarms or ventilation systems.
Many are quite flexible and can be configured to meet the specific
analysis needs for the workplace.
DuPont presented their laboratory validation data of the accuracy of
the Qazi-Ketcham charcoal tube, the PCB charcoal tube, Miran 103 IR
analyzer, 3M 3550 monitor and the Du Pont C-70 badge. Quoting
Elbert V. Kring:
We also believe that OSHA's proposed accuracy in this standard is
appropriate. At plus or minus 25 percent at one part per million, and
plus or minus 35 percent below that. And, our data indicates there's
only one monitoring method, right now, that we've tested thoroughly,
that meets that accuracy requirements. That is the Du Pont Pro-Tek
badge[ast] [ast] [ast]. We also believe that this kind of data should be
confirmed by another independent laboratory, using the same type dynamic
chamber testing (Tr. 1470)
Additional data by an independent laboratory following their exact
protocol was not submitted. However, information was submitted on
comparisons and precision and accuracy of those monitoring procedures
which indicate far better precision and accuracy of those monitoring
procedures than that obtained by Du Pont (Ex. 4-20, 130, 11-68, 11-133,
130, 135A).
The accuracy of any method depends to a large degree upon the skills
and experience of those who not only collect the samples but also those
who analyze the samples. Even for methods that are collaboratively
tested, some laboratories are closer to the true values than others.
Some laboratories may meet the precision and accuracy requirements of
the method; others may consistently far exceed them for the same method.
[49 FR 25796, June 22, 1984, as amended at 50 FR 9801, Mar. 12, 1985; 50
FR 41494, Oct. 11, 1985; 51 FR 25053, July 10, 1986; 53 FR 11436, 11437,
Apr. 6, 1988; 53 FR 27960, July 26, 1988; 54 FR 24334, June 7, 1989; 61
FR 5508, Feb. 13, 1996; 63 FR 1292, Jan. 8, 1998; 67 FR 67965, Nov. 7,
2002]
[[Page 354]]