[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: 29CFR1910.1052]
[Page 426-452]
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. 1910.1052 Methylene Chloride.
This occupational health standard establishes requirements for
employers to control occupational exposure to methylene chloride (MC).
Employees exposed to MC are at increased risk of developing cancer,
adverse effects on the heart, central nervous system and liver, and skin
or eye irritation. Exposure may occur through inhalation, by absorption
through the skin, or through contact with the skin. MC is a solvent
which is used in many different types of work activities, such as paint
stripping, polyurethane foam manufacturing, and cleaning and degreasing.
Under the requirements of paragraph (d) of this section, each covered
employer must make an initial determination of each employee's exposure
to MC. If the employer determines that employees are exposed below the
action level, the only other provisions of this section that apply are
that a record must be made of the determination, the employees must
receive information and training under paragraph (l) of this section
and, where appropriate, employees must be protected from contact with
liquid MC under paragraph (h) of this section. The provisions of the MC
standard are as follows:
(a) Scope and application. This section applies to all occupational
exposures to methylene chloride (MC), Chemical Abstracts Service
Registry Number 75-09-2, in general industry, construction and shipyard
employment.
(b) Definitions. For the purposes of this section, the following
definitions shall apply:
Action level means a concentration of airborne MC of 12.5 parts per
million (ppm) calculated as an eight (8)-hour time-weighted average
(TWA).
Assistant Secretary means the Assistant Secretary of Labor for
Occupational Safety and Health, U.S. Department of Labor, or designee.
Authorized person means any person specifically authorized by the
employer and required by work duties to be present in regulated areas,
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 (d) of this section, or any
other person authorized by the OSH 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, which results, or is likely to result in an uncontrolled
release of MC. If an incidental release of MC can be controlled by
employees such as maintenance personnel at the time of release and in
accordance with the leak/spill provisions required by paragraph (f) of
this section, it is not considered an emergency as defined by this
standard.
Employee exposure means exposure to airborne MC which occurs or
would occur if the employee were not using respiratory protection.
Methylene chloride (MC) means an organic compound with chemical
formula, CH2 Cl2. Its Chemical Abstracts Service
Registry Number is 75-09-2. Its molecular weight is 84.9 g/mole.
Physician or other licensed health care professional is an
individual whose legally permitted scope of practice (i.e., license,
registration, or certification) allows him or her to independently
provide or be delegated the responsibility to provide some or all of the
health care services required by paragraph (j) of this section.
Regulated area means an area, demarcated by the employer, where an
employee's exposure to airborne concentrations of MC exceeds or can
reasonably be expected to exceed either the 8-hour TWA PEL or the STEL.
Symptom means central nervous system effects such as headaches,
disorientation, dizziness, fatigue, and decreased attention span; skin
effects such as chapping, erythema, cracked skin, or skin burns; and
cardiac effects such as chest pain or shortness of breath.
This section means this methylene chloride standard.
(c) Permissible exposure limits (PELs)--(1) Eight-hour time-weighted
average (TWA) PEL. The employer shall ensure
[[Page 427]]
that no employee is exposed to an airborne concentration of MC in excess
of twenty-five parts of MC per million parts of air (25 ppm) as an 8-
hour TWA.
(2) Short-term exposure limit (STEL). The employer shall ensure that
no employee is exposed to an airborne concentration of MC in excess of
one hundred and twenty-five parts of MC per million parts of air (125
ppm) as determined over a sampling period of fifteen minutes.
(d) Exposure monitoring--(1) Characterization of employee exposure.
(i) Where MC is present in the workplace, the employer shall determine
each employee's exposure by either:
(A) Taking a personal breathing zone air sample of each employee's
exposure; or
(B) Taking personal breathing zone air samples that are
representative of each employee's exposure.
(ii) Representative samples. The employer may consider personal
breathing zone air samples to be representative of employee exposures
when they are taken as follows:
(A) 8-hour TWA PEL. The employer has taken one or more personal
breathing zone air samples for at least one employee in each job
classification in a work area during every work shift, and the employee
sampled is expected to have the highest MC exposure.
(B) Short-term exposure limits. The employer has taken one or more
personal breathing zone air samples which indicate the highest likely
15-minute exposures during such operations for at least one employee in
each job classification in the work area during every work shift, and
the employee sampled is expected to have the highest MC exposure.
(C) Exception. Personal breathing zone air samples taken during one
work shift may be used to represent employee exposures on other work
shifts where the employer can document that the tasks performed and
conditions in the workplace are similar across shifts.
(iii) Accuracy of monitoring. The employer shall ensure that the
methods used to perform exposure monitoring produce results that are
accurate to a confidence level of 95 percent, and are:
(A) Within plus or minus 25 percent for airborne concentrations of
MC above the 8-hour TWA PEL or the STEL; or
(B) Within plus or minus 35 percent for airborne concentrations of
MC at or above the action level but at or below the 8-hour TWA PEL.
(2) Initial determination. Each employer whose employees are exposed
to MC shall perform initial exposure monitoring to determine each
affected employee's exposure, except under the following conditions:
(i) Where objective data demonstrate that MC cannot be released in
the workplace in airborne concentrations at or above the action level or
above the STEL. The objective data shall represent the highest MC
exposures likely to occur under reasonably foreseeable conditions of
processing, use, or handling. The employer shall document the objective
data exemption as specified in paragraph (m) of this section;
(ii) Where the employer has performed exposure monitoring within 12
months prior to April 10, 1997 and that exposure monitoring meets all
other requirements of this section, and was conducted under conditions
substantially equivalent to existing conditions; or
(iii) Where employees are exposed to MC on fewer than 30 days per
year (e.g., on a construction site), and the employer has measurements
by direct-reading instruments which give immediate results (such as a
detector tube) and which provide sufficient information regarding
employee exposures to determine what control measures are necessary to
reduce exposures to acceptable levels.
(3) Periodic monitoring. Where the initial determination shows
employee exposures at or above the action level or above the STEL, the
employer shall establish an exposure monitoring program for periodic
monitoring of employee exposure to MC in accordance with Table 1:
[[Page 428]]
Table 1--Initial Determination Exposure Scenarios and Their Associated
Monitoring Frequencies
------------------------------------------------------------------------
Exposure scenario Required monitoring activity
------------------------------------------------------------------------
Below the action level and at No 8-hour TWA or STEL monitoring
or below the STEL. required.
Below the action level and No 8-hour TWA monitoring required;
above the STEL. monitor STEL exposures every three
months.
At or above the action level, Monitor 8-hour TWA exposures every six
at or below the TWA, and at months.
or below the STEL.
At or above the action level, Monitor 8-hour TWA exposures every six
at or below the TWA, and months and monitor STEL exposures every
above the STEL. three months.
Above the TWA and at or below Monitor 8-hour TWA exposures every three
the STEL. months. In addition, without regard to
the last sentence of the note to
paragraph (d)(3), the following
employers must monitor STEL exposures
every three months until either the date
by which they must achieve the 8-hour
TWA PEL under paragraph (n) of this
section or the date by which they in
fact achieve the 8-hour TWA PEL,
whichever comes first: employers engaged
in polyurethane foam manufacturing; foam
fabrication; furniture refinishing;
general aviation aircraft stripping;
product formulation; use of MC-based
adhesives for boat building and repair,
recreational vehicle manufacture, van
conversion, or upholstery; and use of MC
in construction work for restoration and
preservation of buildings, painting and
paint removal, cabinet making, or floor
refinishing and resurfacing.
Above the TWA and above the Monitor 8-hour TWA exposures and STEL
STEL. exposures every three months.
------------------------------------------------------------------------
[Note to paragraph (d)(3):
The employer may decrease the frequency of 8-hour TWA exposure
monitoring to every six months when at least two consecutive
measurements taken at least seven days apart show exposures to be at or
below the 8-hour TWA PEL. The employer may discontinue the periodic 8-
hour TWA monitoring for employees where at least two consecutive
measurements taken at least seven days apart are below the action level.
The employer may discontinue the periodic STEL monitoring for employees
where at least two consecutive measurements taken at least 7 days apart
are at or below the STEL.]
(4) Additional monitoring. (i) The employer shall perform exposure
monitoring when a change in workplace conditions indicates that employee
exposure may have increased. Examples of situations that may require
additional monitoring include changes in production, process, control
equipment, or work practices, or a leak, rupture, or other breakdown.
(ii) Where exposure monitoring is performed due to a spill, leak,
rupture or equipment breakdown, the employer shall clean-up the MC and
perform the appropriate repairs before monitoring.
(5) 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 section, notify each 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) Whenever monitoring results indicate that employee exposure is
above the 8-hour TWA PEL or the STEL, the employer shall describe in the
written notification the corrective action being taken to reduce
employee exposure to or below the 8-hour TWA PEL or STEL and the
schedule for completion of this action.
(6) Observation of monitoring--(i) Employee observation. The
employer shall provide affected employees or their designated
representatives an opportunity to observe any monitoring of employee
exposure to MC conducted in accordance with this section.
(ii) Observation procedures. When observation of the monitoring of
employee exposure to MC requires entry into an area where the use of
protective clothing or equipment is required, the employer shall
provide, at no cost to the observer(s), and the observer(s) shall be
required to use such clothing and equipment and shall comply with all
other applicable safety and health procedures.
(e) Regulated areas. (1) The employer shall establish a regulated
area wherever an employee's exposure to airborne concentrations of MC
exceeds or can reasonably be expected to exceed either the 8-hour TWA
PEL or the STEL.
(2) The employer shall limit access to regulated areas to authorized
persons.
(3) The employer shall supply a respirator, selected in accordance
with
[[Page 429]]
paragraph (h)(3) of this section, to each person who enters a regulated
area and shall require each affected employee to use that respirator
whenever MC exposures are likely to exceed the 8-hour TWA PEL or STEL.
[Note to paragraph (e)(3):
An employer who has implemented all feasible engineering, work
practice and administrative controls (as required in paragraph (f) of
this section), and who has established a regulated area (as required by
paragraph (e)(1) of this section) where MC exposure can be reliably
predicted to exceed the 8-hour TWA PEL or the STEL only on certain days
(for example,because of work or process schedule) would need to have
affected employees use respirators in that regulated area only on those
days.]
(4) The employer shall ensure that, within a regulated area,
employees do not engage in non-work activities which may increase dermal
or oral MC exposure.
(5) The employer shall ensure that while employees are wearing
respirators, they do not engage in activities (such as taking medication
or chewing gum or tobacco) which interfere with respirator seal or
performance.
(6) The employer shall demarcate regulated areas from the rest of
the workplace in any manner that adequately establishes and alerts
employees to the boundaries of the area and minimizes the number of
authorized employees exposed to MC within the regulated area.
(7) An employer at a multi-employer worksite who establishes a
regulated area shall communicate the access restrictions and locations
of these areas to all other employers with work operations at that
worksite.
(f) Methods of compliance--(1) Engineering and work practice
controls. The employer shall institute and maintain the effectiveness of
engineering controls and work practices to reduce employee exposure to
or below the PELs except to the extent that the employer can demonstrate
that such controls are not feasible. Wherever the feasible engineering
controls and work practices which can be instituted are not sufficient
to reduce employee exposure to or below the 8-TWA PEL or STEL, the
employer shall use them to reduce employee exposure to the lowest 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.
(2) Prohibition of rotation. The employer shall not implement a
schedule of employee rotation as a means of compliance with the PELs.
(3) Leak and spill detection. (i) The employer shall implement
procedures to detect leaks of MC in the workplace. In work areas where
spills may occur, the employer shall make provisions to contain any
spills and to safely dispose of any MC-contaminated waste materials.
(ii) The employer shall ensure that all incidental leaks are
repaired and that incidental spills are cleaned promptly by employees
who use the appropriate personal protective equipment and are trained in
proper methods of cleanup.
[Note to paragraph (f)(3)(ii):
See Appendix A of this section for examples of procedures that
satisfy this requirement. Employers covered by this standard may also be
subject to the hazardous waste and emergency response provisions
contained in 29 CFR 1910.120 (q).]
(g) Respiratory protection--(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 when an employee's exposure to MC exceeds the 8-hour TWA
PEL, or STEL (for example, when an employee is using MC in a regulated
area).
(ii) Periods necessary to install or implement feasible engineering
and work-practice controls.
(iii) A few work operations, such as some maintenance operations and
repair activities, for which the employer demonstrates that engineering
and work-practice controls are infeasible.
(iv) Work operations for which feasible engineering and work-
practice controls are not sufficient to reduce employee exposures to or
below the PELs.
(v) Emergencies.
(2) Respirator program. (i) The employer must implement a
respiratory protection program in accordance with 29 CFR 1910.134 (b)
through (m) (except (d)(1)(iii) and (d)(3)(iii)(B) (1) and (2)).
[[Page 430]]
(ii) Employers who provide employees with gas masks with organic-
vapor canisters for the purpose of emergency escape must replace the
canisters after any emergency use and before the gas masks are returned
to service.
(3) Respirator selection. The employer must select appropriate
atmosphere-supplying respirators from Table 2 of this section.
Table 2--Minimum Requirements for Respiratory Protection for Airborne
Methylene Chloride
------------------------------------------------------------------------
Methylene chloride airborne
concentration (ppm) or Minimum respirator required \1\
condition of use
------------------------------------------------------------------------
Up to 625 ppm (25 X PEL)..... (1) Continuous flow supplied-air
respirator, hood or helmet.
Up to 1250 ppm (50 X 8-TWA (1) Full facepiece supplied-air
PEL). respirator operated in negative pressure
(demand) mode.
(2) Full facepiece self-contained
breathing apparatus (SCBA) operated in
negative pressure (demand) mode.
Up to 5000 ppm (200 X 8-TWA (1) Continuous flow supplied-air
PEL). respirator, full facepiece.
(2) Pressure demand supplied-air
respirator, full facepiece.
(3) Positive pressure full facepiece
SCBA.
Unknown concentration, or (1) Positive pressure full facepiece
above 5000 ppm (Greater than SCBA.
200 X 8-TWA PEL).
(2) Full facepiece pressure demand
supplied-air respirator with an
auxiliary self-contained air supply.
Fire fighting................ Positive pressure full facepiece SCBA.
Emergency escape............. (1) Any continuous flow or pressure
demand SCBA.
(2) Gas mask with organic vapor canister.
------------------------------------------------------------------------
\1\ Respirators assigned for higher airborne concentrations may be used
at lower concentrations.
(4) Medical evaluation. Before having an employee use a supplied-air
respirator in the negative-pressure mode, or a gas mask with an organic-
vapor canister for emergency escape, the employer must:
(i) Have a physician or other licensed health-care professional
(PLHCP) evaluate the employee's ability to use such respiratory
protection.
(ii) Ensure that the PLHCP provides their findings in a written
opinion to the employee and the employer.
(h) Protective Work Clothing and Equipment. (1) Where needed to
prevent MC-induced skin or eye irritation, the employer shall provide
clean protective clothing and equipment which is resistant to MC, at no
cost to the employee, and shall ensure that each affected employee uses
it. Eye and face protection shall meet the requirements of 29 CFR
1910.133 or 29 CFR 1915.153, as applicable.
(2) The employer shall clean, launder, repair and replace all
protective clothing and equipment required by this paragraph as needed
to maintain their effectiveness.
(3) The employer shall be responsible for the safe disposal of such
clothing and equipment.
[Note to paragraph (h)(4):
See Appendix A for examples of disposal procedures that will satisfy
this requirement.]
(i) Hygiene facilities. (1) If it is reasonably foreseeable that
employees' skin may contact solutions containing 0.1 percent or greater
MC (for example, through splashes, spills or improper work practices),
the employer shall provide conveniently located washing facilities
capable of removing the MC, and shall ensure that affected employees use
these facilities as needed.
(2) If it is reasonably foreseeable that an employee's eyes may
contact solutions containing 0.1 percent or greater MC (for example
through splashes, spills or improper work practices), the employer shall
provide appropriate eyewash facilities within the immediate work area
for emergency use, and shall ensure that affected employees use those
facilities when necessary.
(j) Medical surveillance--(1) Affected employees. The employer shall
make medical surveillance available for employees who are or may be
exposed to MC as follows:
(i) At or above the action level on 30 or more days per year, or
above the 8- hour TWA PEL or the STEL on 10 or more days per year;
[[Page 431]]
(ii) Above the 8-TWA PEL or STEL for any time period where an
employee has been identified by a physician or other licensed health
care professional as being at risk from cardiac disease or from some
other serious MC-related health condition and such employee requests
inclusion in the medical surveillance program;
(iii) During an emergency.
(2) Costs. The employer shall provide all required medical
surveillance at no cost to affected employees, without loss of pay and
at a reasonable time and place.
(3) Medical personnel. The employer shall ensure that all medical
surveillance procedures are performed by a physician or other licensed
health care professional, as defined in paragraph (b) of this section.
(4) Frequency of medical surveillance. The employer shall make
medical surveillance available to each affected employee as follows:
(i) Initial surveillance. The employer shall provide initial medical
surveillance under the schedule provided by paragraph (n)(2)(iii) of
this section, or before the time of initial assignment of the employee,
whichever is later. The employer need not provide the initial
surveillance if medical records show that an affected employee has been
provided with medical surveillance that complies with this section
within 12 months before April 10, 1997.
(ii) Periodic medical surveillance. The employer shall update the
medical and work history for each affected employee annually. The
employer shall provide periodic physical examinations, including
appropriate laboratory surveillance, as follows:
(A) For employees 45 years of age or older, within 12 months of the
initial surveillance or any subsequent medical surveillance; and
(B) For employees younger than 45 years of age, within 36 months of
the initial surveillance or any subsequent medical surveillance.
(iii) Termination of employment or reassignment. When an employee
leaves the employer's workplace, or is reassigned to an area where
exposure to MC is consistently at or below the action level and STEL,
medical surveillance shall be made available if six months or more have
elapsed since the last medical surveillance.
(iv) Additional surveillance. The employer shall provide additional
medical surveillance at frequencies other than those listed above when
recommended in the written medical opinion. (For example, the physician
or other licensed health care professional may determine an examination
is warranted in less than 36 months for employees younger than 45 years
of age based upon evaluation of the results of the annual medical and
work history.)
(5) Content of medical surveillance--(i) Medical and work history.
The comprehensive medical and work history shall emphasize neurological
symptoms, skin conditions, history of hematologic or liver disease,
signs or symptoms suggestive of heart disease (angina, coronary artery
disease), risk factors for cardiac disease, MC exposures, and work
practices and personal protective equipment used during such exposures.
[Note to paragraph (j)(5)(i):
See Appendix B of this section for an example of a medical and work
history format that would satisfy this requirement.]
(ii) Physical examination. Where physical examinations are provided
as required above, the physician or other licensed health care
professional shall accord particular attention to the lungs,
cardiovascular system (including blood pressure and pulse), liver,
nervous system, and skin. The physician or other licensed health care
professional shall determine the extent and nature of the physical
examination based on the health status of the employee and analysis of
the medical and work history.
(iii) Laboratory surveillance. The physician or other licensed
health care professional shall determine the extent of any required
laboratory surveillance based on the employee's observed health status
and the medical and work history.
[Note to paragraph (j)(5)(iii):
See Appendix B of this section for information regarding medical
tests. Laboratory surveillance may include before- and after-shift
carboxyhemoglobin determinations, resting ECG, hematocrit, liver
function tests and cholesterol levels.]
(iv) Other information or reports. The medical surveillance shall
also include
[[Page 432]]
any other information or reports the physician or other licensed health
care professional determines are necessary to assess the employee's
health in relation to MC exposure.
(6) Content of emergency medical surveillance. The employer shall
ensure that medical surveillance made available when an employee has
been exposed to MC in emergency situations includes, at a minimum:
(i) Appropriate emergency treatment and decontamination of the
exposed employee;
(ii) Comprehensive physical examination with special emphasis on the
nervous system, cardiovascular system, lungs, liver and skin, including
blood pressure and pulse;
(iii) Updated medical and work history, as appropriate for the
medical condition of the employee; and
(iv) Laboratory surveillance, as indicated by the employee's health
status.
[Note to paragraph (j)(6)(iv):
See Appendix B for examples of tests which may be appropriate.]
(7) Additional examinations and referrals. Where the physician or
other licensed health care professional determines it is necessary, the
scope of the medical examination shall be expanded and the appropriate
additional medical surveillance, such as referrals for consultation or
examination, shall be provided.
(8) Information provided to the physician or other licensed health
care professional. The employer shall provide the following information
to a physician or other licensed health care professional who is
involved in the diagnosis of MC-induced health effects:
(i) A copy of this section including its applicable appendices;
(ii) A description of the affected employee's past, current and
anticipated future duties as they relate to the employee's MC exposure;
(iii) The employee's former or current exposure levels or, for
employees not yet occupationally exposed to MC, the employee's
anticipated exposure levels and the frequency and exposure levels
anticipated to be associated with emergencies;
(iv) A description of any personal protective equipment, such as
respirators, used or to be used; and
(v) Information from previous employment-related medical
surveillance of the affected employee which is not otherwise available
to the physician or other licensed health care professional.
(9) Written medical opinions. (i) For each physical examination
required by this section, the employer shall ensure that the physician
or other licensed health care professional provides to the employer and
to the affected employee a written opinion regarding the results of that
examination within 15 days of completion of the evaluation of medical
and laboratory findings, but not more than 30 days after the
examination. The written medical opinion shall be limited to the
following information:
(A) The physician or other licensed health care professional's
opinion concerning whether exposure to MC may contribute to or aggravate
the employee's existing cardiac, hepatic, neurological (including
stroke) or dermal disease or whether the employee has any other medical
condition(s) that would place the employee's health at increased risk of
material impairment from exposure to MC.
(B) Any recommended limitations upon the employee's exposure to MC,
including removal from MC exposure, or upon the employee's use of
respirators, protective clothing, or other protective equipment.
(C) A statement that the employee has been informed by the physician
or other licensed health care professional that MC is a potential
occupational carcinogen, of risk factors for heart disease, and the
potential for exacerbation of underlying heart disease by exposure to MC
through its metabolism to carbon monoxide; and
(D) A statement that the employee has been informed by the physician
or other licensed health care professional of the results of the medical
examination and any medical conditions resulting from MC exposure which
require further explanation or treatment.
(ii) The employer shall instruct the physician or other licensed
health care professional not to reveal to the employer, orally or in the
written opinion, any specific records, findings, and diagnoses that have
no bearing on occupational exposure to MC.
[[Page 433]]
[Note to paragraph (j)(9)(ii):
The written medical opinion may also include information and
opinions generated to comply with other OSHA health standards.]
(10) Medical presumption. For purposes of this paragraph (j) of this
section, the physician or other licensed health care professional shall
presume, unless medical evidence indicates to the contrary, that a
medical condition is unlikely to require medical removal from MC
exposure if the employee is not exposed to MC above the 8-hour TWA PEL.
If the physician or other licensed health care professional recommends
removal for an employee exposed below the 8-hour TWA PEL, the physician
or other licensed health care professional shall cite specific medical
evidence, sufficient to rebut the presumption that exposure below the 8-
hour TWA PEL is unlikely to require removal, to support the
recommendation. If such evidence is cited by the physician or other
licensed health care professional, the employer must remove the
employee. If such evidence is not cited by the physician or other
licensed health care professional, the employer is not required to
remove the employee.
(11) Medical Removal Protection (MRP). (i) Temporary medical removal
and return of an employee.
(A) Except as provided in paragraph (j)(10) of this section, when a
medical determination recommends removal because the employee's exposure
to MC may contribute to or aggravate the employee's existing cardiac,
hepatic, neurological (including stroke), or skin disease, the employer
must provide medical removal protection benefits to the employee and
either:
(1) Transfer the employee to comparable work where methylene
chloride exposure is below the action level; or
(2) Remove the employee from MC exposure.
(B) If comparable work is not available and the employer is able to
demonstrate that removal and the costs of extending MRP benefits to an
additional employee, considering feasibility in relation to the size of
the employer's business and the other requirements of this standard,
make further reliance on MRP an inappropriate remedy, the employer may
retain the additional employee in the existing job until transfer or
removal becomes appropriate, provided:
(1) The employer ensures that the employee receives additional
medical surveillance, including a physical examination at least every 60
days until transfer or removal occurs; and
(2) The employer or PLHCP informs the employee of the risk to the
employee's health from continued MC exposure.
(C) The employer shall maintain in effect any job-related protective
measures or limitations, other than removal, for as long as a medical
determination recommends them to be necessary.
(ii) End of MRP benefits and return of the employee to former job
status.
(A) The employer may cease providing MRP benefits at the earliest of
the following:
(1) Six months;
(2) Return of the employee to the employee's former job status
following receipt of a medical determination concluding that the
employee's exposure to MC no longer will aggravate any cardiac, hepatic,
neurological (including stroke), or dermal disease;
(3) Receipt of a medical determination concluding that the employee
can never return to MC exposure.
(B) For the purposes of this paragraph (j), the requirement that an
employer return an employee to the employee's former job status is not
intended to expand upon or restrict any rights an employee has or would
have had, absent temporary medical removal, to a specific job
classification or position under the terms of a collective bargaining
agreement.
(12) Medical removal protection benefits. (i) For purposes of this
paragraph (j), the term medical removal protection benefits means that,
for each removal, an employer must maintain for up to six months the
earnings, seniority, and other employment rights and benefits of the
employee as though the employee had not been removed from MC exposure or
transferred to a comparable job.
(ii) During the period of time that an employee is removed from
exposure to MC, the employer may condition the
[[Page 434]]
provision of medical removal protection benefits upon the employee's
participation in follow-up medical surveillance made available pursuant
to this section.
(iii) If a removed employee files a workers' compensation claim for
a MC-related disability, the employer shall continue the MRP benefits
required by this paragraph until either the claim is resolved or the 6-
month period for payment f MRP benefits has passed, whichever occurs
first. To the extent the employee is entitled to indemnity payments for
earnings lost during the period of removal, the employer's obligation to
provide medical removal protection benefits to the employee shall be
reduced by the amount of such indemnity payments.
(iv) The employer's obligation to provide medical removal protection
benefits to a removed employee shall be reduced to the extent that the
employee receives compensation for earnings lost during the period of
removal from either a publicly or an employer-funded compensation
program, or receives income from employment with another employer made
possible by virtue of the employee's removal.
(13) Voluntary removal or restriction of an employee. Where an
employer, although not required by this section to do so, removes an
employee from exposure to MC or otherwise places any limitation on an
employee due to the effects of MC exposure on the employee's medical
condition, the employer shall provide medical removal protection
benefits to the employee equal to those required by paragraph (j)(12) of
this section.
(14) Multiple health care professional review mechanism. (i) If the
employer selects the initial physician or licensed health care
professional (PLHCP) to conduct any medical examination or consultation
provided to an employee under this paragraph (j)(11), the employer shall
notify the employee of the right to seek a second medical opinion each
time the employer provides the employee with a copy of the written
opinion of that PLHCP.
(ii) If the employee does not agree with the opinion of the
employer-selected PLHCP, notifies the employer of that fact, and takes
steps to make an appointment with a second PLHCP within 15 days of
receiving a copy of the written opinion of the initial PLHCP, the
employer shall pay for the PLHCP chosen by the employee to perform at
least the following:
(A) Review any findings, determinations or recommendations of the
initial PLHCP; and
(B) Conduct such examinations, consultations, and laboratory tests
as the PLHCP deems necessary to facilitate this review.
(iii) If the findings, determinations or recommendations of the
second PLHCP differ from those of the initial PLHCP, then the employer
and the employee shall instruct the two health care professionals to
resolve the disagreement.
(iv) If the two health care professionals are unable to resolve
their disagreement within 15 days, then those two health care
professionals shall jointly designate a PLHCP who is a specialist in the
field at issue. The employer shall pay for the specialist to perform at
least the following:
(A) Review the findings, determinations, and recommendations of the
first two PLHCPs; and
(B) Conduct such examinations, consultations, laboratory tests and
discussions with the prior PLHCPs as the specialist deems necessary to
resolve the disagreements of the prior health care professionals.
(v) The written opinion of the specialist shall be the definitive
medical determination. The employer shall act consistent with the
definitive medical determination, unless the employer and employee agree
that the written opinion of one of the other two PLHCPs shall be the
definitive medical determination.
(vi) The employer and the employee or authorized employee
representative may agree upon the use of any expeditious alternate
health care professional determination mechanism in lieu of the multiple
health care professional review mechanism provided by this paragraph so
long as the alternate mechanism otherwise satisfies the requirements
contained in this paragraph.
[[Page 435]]
(k) Hazard communication. The employer shall communicate the
following hazards associated with MC on labels and in material safety
data sheets in accordance with the requirements of the Hazard
Communication Standard, 29 CFR 1910.1200, 29 CFR 1915.1200, or 29 CFR
1926.59, as appropiate: cancer, cardiac effects (including elevation of
carboxyhemoglobin), central nervous system effects, liver effects, and
skin and eye irritation.
(l) Employee information and training. (1) The employer shall
provide information and training for each affected employee prior to or
at the time of initial assignment to a job involving potential exposure
to MC.
(2) The employer shall ensure that information and training is
presented in a manner that is understandable to the employees.
(3) In addition to the information required under the Hazard
Communication Standard at 29 CFR 1910.1200, 29 CFR 1915.1200, or 29 CFR
1926.59, as appropiate:
(i) The employer shall inform each affected employee of the
requirements of this section and information available in its
appendices, as well as how to access or obtain a copy of it in the
workplace;
(ii) Wherever an employee's exposure to airborne concentrations of
MC exceeds or can reasonably be expected to exceed the action level, the
employer shall inform each affected employee of the quantity, location,
manner of use, release, and storage of MC and the specific operations in
the workplace that could result in exposure to MC, particularly noting
where exposures may be above the 8-hour TWA PEL or STEL;
(4) The employer shall train each affected employee as required
under the Hazard Communication standard at 29 CFR 1910.1200, 29 CFR
1915.1200, or 29 CFR 1926.59, as appropiate.
(5) The employer shall re-train each affected employee as necessary
to ensure that each employee exposed above the action level or the STEL
maintains the requisite understanding of the principles of safe use and
handling of MC in the workplace.
(6) Whenever there are workplace changes, such as modifications of
tasks or procedures or the institution of new tasks or procedures, which
increase employee exposure, and where those exposures exceed or can
reasonably be expected to exceed the action level, the employer shall
update the training as necessary to ensure that each affected employee
has the requisite proficiency.
(7) An employer whose employees are exposed to MC at a multi-
employer worksite shall notify the other employers with work operations
at that site in accordance with the requirements of the Hazard
Communication Standard, 29 CFR 1910.1200, 29 CFR 1915.1200, or 29 CFR
1926.59, as appropiate.
(8) The employer shall provide to the Assistant Secretary or the
Director, upon request, all available materials relating to employee
information and training.
(m) Recordkeeping--(1) Objective data. (i) Where an employer seeks
to demonstrate that initial monitoring is unnecessary through reasonable
reliance on objective data showing that any materials in the workplace
containing MC will not release MC at levels which exceed the action
level or the STEL under foreseeable conditions of exposure, the employer
shall establish and maintain an accurate record of the objective data
relied upon in support of the exemption.
(ii) This record shall include at least the following information:
(A) The MC-containing material in question;
(B) The source of the objective data;
(C) The testing protocol, results of testing, and/or analysis of the
material for the release of MC;
(D) A description of the operation exempted under paragraph
(d)(2)(i) of this section 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 establish and keep
an accurate record of all measurements
[[Page 436]]
taken to monitor employee exposure to MC as prescribed in paragraph (d)
of this section.
(ii) Where the employer has 20 or more employees, this record shall
include at least the following information:
(A) The date of measurement for each sample taken;
(B) The operation involving exposure to MC 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 personal protective equipment, such as respiratory
protective devices, worn, if any; and
(F) Name, social security number, job classification and exposure of
all of the employees represented by monitoring, indicating which
employees were actually monitored.
(iii) Where the employer has fewer than 20 employees, the record
shall include at least the following information:
(A) The date of measurement for each sample taken;
(B) Number, duration, and results of samples taken; and
(C) Name, social security number, job classification and exposure of
all of the employees represented by monitoring, indicating which
employees were actually monitored.
(iv) The employer shall maintain this record for at least thirty
(30) years, in accordance with 29 CFR 1910.1020.
(3) Medical surveillance. (i) The employer shall establish and
maintain an accurate record for each employee subject to medical
surveillance under paragraph (j) of this section.
(ii) The record shall include at least the following information:
(A) The name, social security number and description of the duties
of the employee;
(B) Written medical opinions; and
(C) Any employee medical conditions related to exposure to MC.
(iii) The employer shall ensure that this record is maintained for
the duration of employment plus thirty (30) years, in accordance with 29
CFR 1910.1020.
(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 in
accordance with 29 CFR 1910.1020.
[Note to paragraph (m)(4)(i):
All records required to be maintained by this section may be kept in
the most administratively convenient form (for example, electronic or
computer records would satisfy this requirement).]
(ii) The employer, upon request, shall make any employee exposure
and objective data records required by this section available for
examination and copying by affected employees, former employees, and
designated representatives in accordance with 29 CFR 1910.1020.
(iii) The employer, upon request, shall make employee medical
records required to be kept by this section available for examination
and copying by the subject employee and by anyone having the specific
written consent of the subject employee in accordance with 29 CFR
1910.1020.
(5) Transfer of records. The employer shall comply with the
requirements concerning transfer of records set forth in 29 CFR
1910.1020(h).
(n) Dates--(1) Effective date. This section shall become effective
April 10, 1997.
(2) Start-up dates. (i) Initial monitoring required by paragraph
(d)(2) of this section shall be completed according to the following
schedule:
(A) For employers with fewer than 20 employees, within 300 days
after the effective date of this section.
(B) For polyurethane foam manufacturers with 20 to 99 employees,
within 255 days after the effective date of this section.
(C) For all other employers, within 150 days after the effective
date of this section.
(ii) Engineering controls required under paragraph (f)(1) of this
section shall be implemented according to the following schedule:
(A) For employers with fewer than 20 employees: within three (3)
years after the effective date of this section.
(B) For employers with fewer than 150 employees engaged in foam
fabrication; for employers with fewer than 50
[[Page 437]]
employees engaged in furniture refinishing, general aviation aircraft
stripping, and product formulation; for employers with fewer than 50
employees using MC-based adhesives for boat building and repair,
recreational vehicle manufacture, van conversion, and upholstering; for
employers with fewer than 50 employees using MC in construction work for
restoration and preservation of buildings, painting and paint removal,
cabinet making and/or floor refinishing and resurfacing: within three
(3) years after the effective date of this section.
(C) For employers engaged in polyurethane foam manufacturing with 20
employees or more: within thirty (30) months after the effective date of
this section.
(D) For employers with 150 or more employees engaged in foam
fabrication; for employers with 50 or more employees engaged in
furniture refinishing, general aviation aircraft stripping, and product
formulation; for employers with 50 or more employees using MC-based
adhesives in boat building and repair, recreational vehicle manufacture,
van conversion and upholstering; and for employers with 50 or more
employees using MC in construction work for restoration and preservation
of buildings, painting and paint removal, cabinet making and/or floor
refinishing and resurfacing: within two (2) years after the effective
date of this section.
(E) For all other employers: within one (1) year after the effective
date of this section.
(iii) Employers identified in paragraphs (n)(2)(ii)(B), (C), and (D)
of this section shall comply with the requirements listed below in this
subparagraph by the dates indicated:
(A) Use of respiratory protection whenever an employee's exposure to
MC exceeds or can reasonably be expected to exceed the 8-hour TWA PEL,
in accordance with paragraphs (c)(1), (e)(3), (f)(1) and (g)(1) of this
section: by the applicable dates set out in paragraphs (n)(2)(ii)(B),
(C) and (D) of this section for the installation of engineering
controls.
(B) Use of respiratory protection whenever an employee's exposure to
MC exceeds or can reasonably be expected to exceed the STEL in
accordance with paragraphs (e)(3), (f)(1), and (g)(1) of this section:
by the applicable dates indicated in paragraph (n)(2)(iv) of this
section.
(C) Implementation of work practices (such as leak and spill
detection, cleanup and enclosure of containers) required by paragraph
(f)(1) of this section: by the applicable dates indicated in paragraph
(n)(2)(iv) of this section.
(D) Notification of corrective action under paragraph (d)(5)(ii) of
this section: no later than (90) days before the compliance date
applicable to such corrective action.
(iv) Unless otherwise specified in this paragraph (n), all other
requirements of this section shall be complied with according to the
following schedule:
(A) For employers with fewer than 20 employees, within one (1) year
after the effective date of this section.
(B) For employers engaged in polyurethane foam manufacturing with 20
to 99 employees, within 270 days after the effective date of this
section.
(C) For all other employers, within 255 days after the effective
date of this section.
(3) Transitional dates. The exposure limits for MC specified in 29
CFR 1910.1000 (1996), Table Z-2, shall remain in effect until the start-
up dates for the exposure limits specified in paragraph (n) of this
section, or if the exposure limits in this section are stayed or
vacated.
(o) Appendices. The information contained in the appendices does
not, by itself, create any additional obligations not otherwise imposed
or detract from any existing obligation.
[Note to paragraph (o):
The requirement of 29 CFR 1910.1052(g)(1) to use respiratory
protection whenever an employee's exposure to methylene chloride exceeds
or can reasonably be expected to exceed the 8-hour TWA PEL is hereby
stayed until August 31, 1998 for employers engaged in polyurethane foam
manufacturing; foam fabrication; furniture refinishing; general aviation
aircraft stripping; formulation of products containing methylene
chloride; boat building and repair; recreational vehicle manufacture;
van conversion; upholstery; and use of methylene chloride in
construction work for restoration and preservation of buildings,
painting and paint removal, cabinet making and/or floor refinishing and
resurfacing.
The requirement of 29 CFR 1910.1052(f)(1) to implement engineering
controls to achieve
[[Page 438]]
the 8-hour TWA PEL and STEL is hereby stayed until December 10, 1998 for
employers with more than 100 employees engaged in polyurethane foam
manufacturing and for employers with more than 20 employees engaged in
foam fabrication; furniture refinishing; general aviation aircraft
stripping; formulation of products containing methylene chloride; boat
building and repair; recreational vehicle manufacture; van conversion;
upholstery; and use of methylene chloride in construction work for
restoration and preservation of buildings, painting and paint removal,
cabinet making and/or floor refinishing and resurfacing.]
Appendix A to Section 1910.1052--Substance Safety Data Sheet and
Technical Guidelines for Methylene Chloride
I. Substance Identification
A. Substance: Methylene chloride (CH2 Cl2).
B. Synonyms: MC, Dichloromethane (DCM); Methylene dichloride;
Methylene bichloride; Methane dichloride; CAS: 75-09-2; NCI-C50102.
C. Physical data:
1. Molecular weight: 84.9.
2. Boiling point (760 mm Hg): 39.8 deg.C (104 deg.F).
3. Specific gravity (water=1): 1.3.
4. Vapor density (air=1 at boiling point): 2.9.
5. Vapor pressure at 20 deg.C (68 deg.F): 350 mm Hg.
6. Solubility in water, g/100 g water at 20 deg.C (68 deg.F)=1.32.
7. Appearance and odor: colorless liquid with a chloroform-like
odor.
D. Uses:
MC is used as a solvent, especially where high volatility is
required. It is a good solvent for oils, fats, waxes, resins, bitumen,
rubber and cellulose acetate and is a useful paint stripper and
degreaser. It is used in paint removers, in propellant mixtures for
aerosol containers, as a solvent for plastics, as a degreasing agent, as
an extracting agent in the pharmaceutical industry and as a blowing
agent in polyurethane foams. Its solvent property is sometimes increased
by mixing with methanol, petroleum naphtha or tetrachloroethylene.
E. Appearance and odor:
MC is a clear colorless liquid with a chloroform-like odor. It is
slightly soluble in water and completely miscible with most organic
solvents.
F. Permissible exposure:
Exposure may not exceed 25 parts MC per million parts of air (25
ppm) as an eight-hour time-weighted average (8-hour TWA PEL) or 125
parts of MC per million parts of air (125 ppm) averaged over a 15-minute
period (STEL).
II. Health Hazard Data
A. MC can affect the body if it is inhaled or if the liquid comes in
contact with the eyes or skin. It can also affect the body if it is
swallowed.
B. Effects of overexposure:
1. Short-term Exposure:
MC is an anesthetic. Inhaling the vapor may cause mental confusion,
light-headedness, nausea, vomiting, and headache. Continued exposure may
cause increased light-headedness, staggering, unconsciousness, and even
death. High vapor concentrations may also cause irritation of the eyes
and respiratory tract. Exposure to MC may make the symptoms of angina
(chest pains) worse. Skin exposure to liquid MC may cause irritation. If
liquid MC remains on the skin, it may cause skin burns. Splashes of the
liquid into the eyes may cause irritation.
2. Long-term (chronic) exposure:
The best evidence that MC causes cancer is from laboratory studies
in which rats, mice and hamsters inhaled MC 6 hours per day, 5 days per
week for 2 years. MC exposure produced lung and liver tumors in mice and
mammary tumors in rats. No carcinogenic effects of MC were found in
hamsters.
There are also some human epidemiological studies which show an
association between occupational exposure to MC and increases in biliary
(bile duct) cancer and a type of brain cancer. Other epidemiological
studies have not observed a relationship between MC exposure and cancer.
OSHA interprets these results to mean that there is suggestive (but not
absolute) evidence that MC is a human carcinogen.
C. 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 MC.
D. Warning Properties:
1. Odor Threshold:
Different authors have reported varying odor thresholds for MC.
Kirk-Othmer and Sax both reported 25 to 50 ppm; Summer and May both
reported 150 ppm; Spector reports 320 ppm. Patty, however, states that
since one can become adapted to the odor, MC should not be considered to
have adequate warning properties.
2. Eye Irritation Level:
Kirk-Othmer reports that ``MC vapor is seriously damaging to the
eyes.'' Sax agrees with Kirk-Othmer's statement. The ACGIH Documentation
of TLVs states that irritation of the eyes has been observed in workers
exposed to concentrations up to 5000 ppm.
3. Evaluation of Warning Properties:
Since a wide range of MC odor thresholds are reported (25-320 ppm),
and human adaptation to the odor occurs, MC is considered to be a
material with poor warning properties.
[[Page 439]]
III. Emergency First Aid Procedures
In the event of emergency, institute first aid procedures and send
for first aid or medical assistance.
A. Eye and Skin Exposures:
If there is a potential for liquid MC to come in contact with eye or
skin, face shields and skin protective equipment must be provided and
used. If liquid MC comes in contact with the eye, get medical attention.
Contact lenses should not be worn when working with this chemical.
B. Breathing:
If a person breathes in large amounts of MC, move the exposed person
to fresh air at once. If breathing has stopped, perform cardiopulmorary
resuscitation. Keep the affected person warm and at rest. Get medical
attention as soon as possible.
C. Rescue:
Move the affected person from the hazardous exposure immediately. If
the exposed person has been overcome, notify someone else and put into
effect the established emergency rescue procedures. Understand the
facility's emergency rescue procedures and know the locations of rescue
equipment before the need arises. Do not become a casualty yourself.
IV. Respirators, Protective Clothing, and Eye Protection
A. Respirators:
Good industrial hygiene practices recommend that engineering
controls be used to reduce environmental concentrations to the
permissible exposure level. However, there are some exceptions where
respirators may be used to control exposure. Respirators may be used
when engineering and work practice controls are not feasible, when such
controls are in the process of being installed, or when these controls
fail and need to be supplemented. Respirators may also be used for
operations which require entry into tanks or closed vessels, and in
emergency situations.
If the use of respirators is necessary, the only respirators
permitted are those that have been approved by the Mine Safety and
Health Administration (MSHA) or the National Institute for Occupational
Safety and Health (NIOSH). Supplied-air respirators are required because
air-purifying respirators do not provide adequate respiratory protection
against MC.
In addition to respirator selection, a complete written respiratory
protection program should be instituted which includes regular training,
maintenance, inspection, cleaning, and evaluation. If you can smell MC
while wearing a respirator, proceed immediately to fresh air. If you
experience difficulty in breathing while wearing a respirator, tell your
employer.
B. Protective Clothing:
Employees must be provided with and required to use impervious
clothing, gloves, face shields (eight-inch minimum), and other
appropriate protective clothing necessary to prevent repeated or
prolonged skin contact with liquid MC or contact with vessels containing
liquid MC. Any clothing which becomes wet with liquid MC should be
removed immediately and not reworn until the employer has ensured that
the protective clothing is fit for reuse. Contaminated protective
clothing should be placed in a regulated area designated by the employer
for removal of MC before the clothing is laundered or disposed of.
Clothing and equipment should remain in the regulated area until all of
the MC contamination has evaporated; clothing and equipment should then
be laundered or disposed of as appropriate.
C. Eye Protection:
Employees should be provided with and required to use splash-proof
safety goggles where liquid MC may contact the eyes.
V. Housekeeping and Hygiene Facilities
For purposes of complying with 29 CFR 1910.141, the following items
should be emphasized:
A. The workplace should be kept clean, orderly, and in a sanitary
condition. The employer should institute a leak and spill detection
program for operations involving liquid MC in order to detect sources of
fugitive MC emissions.
B. Emergency drench showers and eyewash facilities are recommended.
These should be maintained in a sanitary condition. Suitable cleansing
agents should also be provided to assure the effective removal of MC
from the skin.
C. Because of the hazardous nature of MC, contaminated protective
clothing should be placed in a regulated area designated by the employer
for removal of MC before the clothing is laundered or disposed of.
VI. Precautions for Safe Use, Handling, and Storage
A. Fire and Explosion Hazards:
MC has no flash point in a conventional closed tester, but it forms
flammable vapor-air mixtures at approximately 100 deg.C (212 deg.F),
or higher. It has a lower explosion limit of 12%, and an upper explosion
limit of 19% in air. It has an autoignition temperature of 556.1 deg.C
(1033 deg.F), and a boiling point of 39.8 deg.C (104 deg.F). It is
heavier than water with a specific gravity of 1.3. It is slightly
soluble in water.
B. Reactivity Hazards:
Conditions contributing to the instability of MC are heat and
moisture. Contact with strong oxidizers, caustics, and chemically active
metals such as aluminum or magnesium powder, sodium and potassium may
cause fires and explosions.
[[Page 440]]
Special precautions: Liquid MC will attack some forms of plastics,
rubber, and coatings.
C. Toxicity:
Liquid MC is painful and irritating if splashed in the eyes or if
confined on the skin by gloves, clothing, or shoes. Vapors in high
concentrations may cause narcosis and death. Prolonged exposure to
vapors may cause cancer or exacerbate cardiac disease.
D. Storage:
Protect against physical damage. Because of its corrosive
properties, and its high vapor pressure, MC should be stored in plain,
galvanized or lead lined, mild steel containers in a cool, dry, well
ventilated area away from direct sunlight, heat source and acute fire
hazards.
E. Piping Material:
All piping and valves at the loading or unloading station should be
of material that is resistant to MC and should be carefully inspected
prior to connection to the transport vehicle and periodically during the
operation.
F. Usual Shipping Containers:
Glass bottles, 5- and 55-gallon steel drums, tank cars, and tank
trucks.
Note: This section addresses MC exposure in marine terminal and
longshore employment only where leaking or broken packages allow MC
exposure that is not addressed through compliance with 29 CFR parts 1917
and 1918, respectively.
G. Electrical Equipment:
Electrical installations in Class I hazardous locations as defined
in Article 500 of the National Electrical Code, should be installed
according to Article 501 of the code; and electrical equipment should be
suitable for use in atmospheres containing MC vapors. See Flammable and
Combustible Liquids Code (NFPA No. 325M), Chemical Safety Data Sheet SD-
86 (Manufacturing Chemists' Association, Inc.).
H. Fire Fighting:
When involved in fire, MC emits highly toxic and irritating fumes
such as phosgene, hydrogen chloride and carbon monoxide. Wear breathing
apparatus and use water spray to keep fire-exposed containers cool.
Water spray may be used to flush spills away from exposures.
Extinguishing media are dry chemical, carbon dioxide, foam. For purposes
of compliance with 29 CFR 1910.307, locations classified as hazardous
due to the presence of MC shall be Class I.
I. Spills and Leaks:
Persons not wearing protective equipment and clothing should be
restricted from areas of spills or leaks until cleanup has been
completed. If MC has spilled or leaked, the following steps should be
taken:
1. Remove all ignition sources.
2. Ventilate area of spill or leak.
3. Collect for reclamation or absorb in vermiculite, dry sand,
earth, or a similar material.
J. Methods of Waste Disposal:
Small spills should be absorbed onto sand and taken to a safe area
for atmospheric evaporation. Incineration is the preferred method for
disposal of large quantities by mixing with a combustible solvent and
spraying into an incinerator equipped with acid scrubbers to remove
hydrogen chloride gases formed. Complete combustion will convert carbon
monoxide to carbon dioxide. Care should be taken for the presence of
phosgene.
K. You should not keep food, beverage, or smoking materials, or eat
or smoke in regulated areas where MC concentrations are above the
permissible exposure limits.
L. Portable heating units should not be used in confined areas where
MC is used.
M. Ask your supervisor where MC is used in your work area and for
any additional plant safety and health rules.
VII. Medical Requirements
Your employer is required to offer you the opportunity to
participate in a medical surveillance program if you are exposed to MC
at concentrations at or above the action level (12.5 ppm 8-hour TWA) for
more than 30 days a year or at concentrations exceeding the PELs (25 ppm
8-hour TWA or 125 ppm 15-minute STEL) for more than 10 days a year. If
you are exposed to MC at concentrations over either of the PELs, your
employer will also be required to have a physician or other licensed
health care professional ensure that you are able to wear the respirator
that you are assigned. Your employer must provide all medical
examinations relating to your MC exposure at a reasonable time and place
and at no cost to you.
VIII. 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 must
be taken in the employee's breathing zone.
2. Monitoring techniques: The sampling and analysis under this
section may be performed by collection of the MC vapor on two charcoal
adsorption tubes in series 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 MC in employees'' breathing zones.
OSHA method 80 is an example of a validated method of sampling and
analysis of
[[Page 441]]
MC. Copies of this method are available from OSHA or can be downloaded
from the Internet at http://www.osha.gov. The employer has the
obligation of selecting a monitoring method which meets the accuracy and
precision requirements of the standard under his or her unique field
conditions. The standard requires that the method of monitoring must be
accurate, to a 95 percent confidence level, to plus or minus 25 percent
for concentrations of MC at or above 25 ppm, and to plus or minus 35
percent for concentrations at or below 25 ppm. In addition to OSHA
method 80, there are numerous other methods available for monitoring for
MC in the workplace.
B. Since many of the duties relating to employee exposure are
dependent on the results of measurement procedures, employers must
assure that the evaluation of employee exposure is performed by a
technically qualified person.
IX. Observation of Monitoring
Your employer is required to perform measurements that are
representative of your exposure to MC and you or your designated
representative are entitled to observe the monitoring procedure. You are
entitled to observe the steps taken in the measurement procedure, and to
record the results obtained. When the monitoring procedure is taking
place in an area where respirators or personal protective clothing and
equipment are required to be worn, you or your representative must also
be provided with, and must wear, protective clothing and equipment.
X. Access To Information
A. Your employer is required to inform you of the information
contained in this Appendix. In addition, your employer must instruct you
in the proper work practices for using MC, emergency procedures, and the
correct use of protective equipment.
B. Your employer is required to determine whether you are being
exposed to MC. 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 determines
that you are being over exposed, 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 records must be kept by the employer for at
least thirty (30) years.
D. Your employer is required to release your exposure and medical
records to you or your representative upon your request.
E. Your employee is required to provide labels and material safety
data sheets (MSDS) for all materials, mixtures or solutions composed of
greater than 0.1 percent MC. An example of a label that would satisfy
these requirements would be:
Danger Contains Methylene Chloride Potential Cancer Hazard
May worsen heart disease because methylene chloride is converted to
carbon monoxide in the body.
May cause dizziness, headache, irritation of the throat and lungs,
loss of consciousness and death at high concentrations (for example, if
used in a poorly ventilated room).
Avoid Skin Contact. Contact with liquid causes skin and eye
irritation.
XI. Common Operations and Controls
The following list includes some common operations in which exposure
to MC may occur and control methods which may be effective in each case:
------------------------------------------------------------------------
Operations Controls
------------------------------------------------------------------------
Use as solvent in paint and varnish General dilution
removers; manufacture of aerosols; cold ventilation; local exhaust
cleaning and ultrasonic cleaning; and as ventilation; personal
a solvent in furniture stripping. protective equipment;
substitution.
Use as solvent in vapor degreasing........ Process enclosure; local
exhaust ventilation;
chilling coils;
substitution.
Use as a secondary refrigerant in air General dilution
conditioning and scientific testing. ventilation; local exhaust
ventilation; personal
protective equipment.
------------------------------------------------------------------------
Appendix B to Section 1910.105--Medical Surveillance for Methylene
Chloride
I. Primary Route of Entry
Inhalation.
II. Toxicology
Methylene Chloride (MC) is primarily an inhalation hazard. The
principal acute hazardous effects are the depressant action on the
central nervous system, possible cardiac toxicity and possible liver
toxicity. The range of CNS effects are from decreased eye/hand
coordination and decreased performance in vigilance tasks to narcosis
and even death of individuals exposed at very high doses. Cardiac
toxicity is due to the metabolism of MC to carbon monoxide, and the
effects of carbon monoxide on heart tissue. Carbon monoxide displaces
oxygen in the blood, decreases the oxygen available to heart tissue,
increasing the risk of damage to the heart, which may result in heart
attacks in susceptible individuals. Susceptible individuals include
persons with heart disease and those with risk factors for heart
disease.
Elevated liver enzymes and irritation to the respiratory passages
and eyes have also
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been reported for both humans and experimental animals exposed to MC
vapors.
MC is metabolized to carbon monoxide and carbon dioxide via two
separate pathways. Through the first pathway, MC is metabolized to
carbon monoxide as an end-product via the P-450 mixed function oxidase
pathway located in the microsomal fraction of the cell. This
biotransformation of MC to carbon monoxide occurs through the process of
microsomal oxidative dechlorination which takes place primarily in the
liver. The amount of conversion to carbon monoxide is significant as
measured by the concentration of carboxyhemoglobin, up to 12% measured
in the blood following occupational exposure of up to 610 ppm. Through
the second pathway, MC is metabolized to carbon dioxide as an end
product (with formaldehyde and formic acid as metabolic intermediates)
via the glutathione dependent enzyme found in the cytosolic fraction of
the liver cell. Metabolites along this pathway are believed to be
associated with the carcinogenic activity of MC.
MC has been tested for carcinogenicity in several laboratory
rodents. These rodent studies indicate that there is clear evidence that
MC is carcinogenic to male and female mice and female rats. Based on
epidemiologic studies, OSHA has concluded that there is suggestive
evidence of increased cancer risk in MC-related worker populations. The
epidemiological evidence is consistent with the finding of excess cancer
in the experimental animal studies. NIOSH regards MC as a potential
occupational carcinogen and the International Agency for Research Cancer
(IARC) classifies MC as an animal carcinogen. OSHA considers MC as a
suspected human carcinogen.
III. Medical Signs and Symptoms of Acute Exposure
Skin exposure to liquid MC may cause irritation or skin burns.
Liquid MC can also be irritating to the eyes. MC is also absorbed
through the skin and may contribute to the MC exposure by inhalation.
At high concentrations in air, MC may cause nausea, vomiting, light-
headedness, numbness of the extremities, changes in blood enzyme levels,
and breathing problems, leading to bronchitis and pulmonary edema,
unconsciousness and even death.
At lower concentrations in air, MC may cause irritation to the skin,
eye, and respiratory tract and occasionally headache and nausea. Perhaps
the greatest problem from exposure to low concentrations of MC is the
CNS effects on coordination and alertness that may cause unsafe
operations of machinery and equipment, leading to self-injury or
accidents.
Low levels and short duration exposures do not seem to produce
permanent disability, but chronic exposures to MC have been demonstrated
to produce liver toxicity in animals, and therefore, the evidence is
suggestive for liver toxicity in humans after chronic exposure.
Chronic exposure to MC may also cause cancer.
IV. Surveillance and Preventive Considerations
As discussed above, MC is classified as a suspect or potential human
carcinogen. It is a central nervous system (CNS) depressant and a skin,
eye and respiratory tract irritant. At extremely high concentrations, MC
has caused liver damage in animals.
MC principally affects the CNS, where it acts as a narcotic. The
observation of the symptoms characteristic of CNS depression, along with
a physical examination, provides the best detection of early
neurological disorders. Since exposure to MC also increases the
carboxyhemoglobin level in the blood, ambient carbon monoxide levels
would have an additive effect on that carboxyhemoglobin level. Based on
such information, a periodic post-shift carboxyhemoglobin test as an
index of the presence of carbon monoxide in the blood is recommended,
but not required, for medical surveillance.
Based on the animal evidence and three epidemiologic studies
previously mentioned, OSHA concludes that MC is a suspect human
carcinogen. The medical surveillance program is designed to observe
exposed workers on a regular basis. While the medical surveillance
program cannot detect MC-induced cancer at a preneoplastic stage, OSHA
anticipates that, as in the past, early detection and treatments of
cancers leading to enhanced survival rates will continue to evolve.
A. Medical and Occupational History:
The medical and occupational work history plays an important role in
the initial evaluation of workers exposed to MC. It is therefore
extremely important for the examining physician or other licensed health
care professional to evaluate the MC-exposed worker carefully and
completely and to focus the examination on MC's potentially associated
health hazards. The medical evaluation must include an annual detailed
work and medical history with special emphasis on cardiac history and
neurological symptoms.
An important goal of the medical history is to elicit information
from the worker regarding potential signs or symptoms associated with
increased levels of carboxyhemoglobin due to the presence of carbon
monoxide in the blood. Physicians or other licensed health care
professionals should ensure that the smoking history of all MC exposed
employees is known. Exposure to MC may cause a significant increase in
carboxyhemoglobin level in all exposed
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persons. However, smokers as well as workers with anemia or heart
disease and those concurrently exposed to carbon monoxide are at
especially high risk of toxic effects because of an already reduced
oxygen carrying capacity of the blood.
A comprehensive or interim medical and work history should also
include occurrence of headache, dizziness, fatigue, chest pain,
shortness of breath, pain in the limbs, and irritation of the skin and
eyes.
In addition, it is important for the physician or other licensed
health care professional to become familiar with the operating
conditions in which exposure to MC is likely to occur. The physician or
other licensed health care professional also must become familiar with
the signs and symptoms that may indicate that a worker is receiving
otherwise unrecognized and exceptionally high exposure levels of MC.
An example of a medical and work history that would satisfy the
requirement for a comprehensive or interim work history is represented
by the following:
The following is a list of recommended questions and issues for the
self-administered questionnaire for methylene chloride exposure.
Questionnaire For Methylene Chloride Exposure
I. Demographic Information
1. Name
2. Social Security Number
3. Date
4. Date of Birth
5. Age
6. Present occupation
7. Sex
8. Race
II. Occupational History
1. Have you ever worked with methylene chloride, dichloromethane,
methylene dichloride, or CH2 Cl2 (all are
different names for the same chemical)? Please list which on the
occupational history form if you have not already.
2. If you have worked in any of the following industries and have
not listed them on the occupational history form, please do so.
Furniture stripping
Polyurethane foam manufacturing
Chemical manufacturing or formulation
Pharmaceutical manufacturing
Any industry in which you used solvents to clean and degrease equipment
or parts
Construction, especially painting and refinishing
Aerosol manufacturing
Any industry in which you used aerosol adhesives
3. If you have not listed hobbies or household projects on the
occupational history form, especially furniture refinishing, spray
painting, or paint stripping, please do so.
III. Medical History
A. General
1. Do you consider yourself to be in good health? If no, state
reason(s).
2. Do you or have you ever had:
a. Persistent thirst
b. Frequent urination (three times or more at night)
c. Dermatitis or irritated skin
d. Non-healing wounds
3. What prescription or non-prescription medications do you take,
and for what reasons?
4. Are you allergic to any medications, and what type of reaction do
you have?
B. Respiratory
1. Do you have or have you ever had any chest illnesses or diseases?
Explain.
2. Do you have or have you ever had any of the following:
a. Asthma
b. Wheezing
c. Shortness of breath
3. Have you ever had an abnormal chest X-ray? If so, when, where,
and what were the findings?
4. Have you ever had difficulty using a respirator or breathing
apparatus? Explain.
5. Do any chest or lung diseases run in your family? Explain.
6. Have you ever smoked cigarettes, cigars, or a pipe? Age started:
7. Do you now smoke?
8. If you have stopped smoking completely, how old were you when you
stopped?
9. On the average of the entire time you smoked, how many packs of
cigarettes, cigars, or bowls of tobacco did you smoke per day?
C. Cardiovascular
1. Have you ever been diagnosed with any of the following: Which of
the following apply to you now or did apply to you at some time in the
past, even if the problem is controlled by medication? Please explain
any yes answers (i.e., when problem was diagnosed, length of time on
medication).
a. High cholesterol or triglyceride level
b. Hypertension (high blood pressure)
c. Diabetes
d. Family history of heart attack, stroke, or blocked arteries
2. Have you ever had chest pain? If so, answer the next five
questions.
a. What was the quality of the pain (i.e., crushing, stabbing,
squeezing)?
b. Did the pain go anywhere (i.e., into jaw, left arm)?
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c. What brought the pain out?
d. How long did it last?
e. What made the pain go away?
3. Have you ever had heart disease, a heart attack, stroke,
aneurysm, or blocked arteries anywhere in you body? Explain (when,
treatment).
4. Have you ever had bypass surgery for blocked arteries in your
heart or anywhere else? Explain.
5. Have you ever had any other procedures done to open up a blocked
artery (balloon angioplasty, carotid endarterectomy, clot-dissolving
drug)?
6. Do you have or have you ever had (explain each):
a. Heart murmur
b. Irregular heartbeat
c. Shortness of breath while lying flat
d. Congestive heart failure
e. Ankle swelling
f. Recurrent pain anywhere below the waist while walking
7. Have you ever had an electrocardiogram (EKG)? When?
8. Have you ever had an abnormal EKG? If so, when, where, and what
were the findings?
9. Do any heart diseases, high blood pressure, diabetes, high
cholesterol, or high triglycerides run in your family? Explain.
D. Hepatobiliary and Pancreas
1. Do you now or have you ever drunk alcoholic beverages? Age
started: -------- Age stopped: --------.
2. Average numbers per week:
a. Beers: --------, ounces in usual container:
b. Glasses of wine: --------, ounces per glass:
c. Drinks: --------, ounces in usual container:
3. Do you have or have you ever had (explain each):
a. Hepatitis (infectious, autoimmune, drug-induced, or chemical)
b. Jaundice
c. Elevated liver enzymes or elevated bilirubin
d. Liver disease or cancer
E. Central Nervous System
1. Do you or have you ever had (explain each):
a. Headache
b. Dizziness
c. Fainting
d. Loss of consciousness
e. Garbled speech
f. Lack of balance
g. Mental/psychiatric illness
h. Forgetfulness
F. Hematologic
1. Do you have, or have you ever had (explain each):
a. Anemia
b. Sickle cell disease or trait
c. Glucose-6-phosphate dehydrogenase deficiency
d. Bleeding tendency disorder
2. If not already mentioned previously, have you ever had a reaction
to sulfa drugs or to drugs used to prevent or treat malaria? What was
the drug? Describe the reaction.
B. Physical Examination
The complete physical examination, when coupled with the medical and
occupational history, assists the physician or other licensed health
care professional in detecting pre-existing conditions that might place
the employee at increased risk, and establishes a baseline for future
health monitoring. These examinations should include:
1. Clinical impressions of the nervous system, cardiovascular
function and pulmonary function, with additional tests conducted where
indicated or determined by the examining physician or other licensed
health care professional to be necessary.
2. An evaluation of the advisability of the worker using a
respirator, because the use of certain respirators places an additional
burden on the cardiopulmonary system. It is necessary for the attending
physician or other licensed health care professional to evaluate the
cardiopulmonary function of these workers, in order to inform the
employer in a written medical opinion of the worker's ability or fitness
to work in an area requiring the use of certain types of respiratory
protective equipment. The presence of facial hair or scars that might
interfere with the worker's ability to wear certain types of respirators
should also be noted during the examination and in the written medical
opinion.
Because of the importance of lung function to workers required to
wear certain types of respirators to protect themselves from MC
exposure, these workers must receive an assessment of pulmonary function
before they begin to wear a negative pressure respirator and at least
annually thereafter. The recommended pulmonary function tests 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 the ratios of measured FVC and measured FEV1
to expected respective values corrected for variation due to age, sex,
race, and height. Pulmonary function evaluation must be conducted by a
physician or other licensed health care professional experienced in
pulmonary function tests.
The following is a summary of the elements of a physical exam which
would fulfill the requirements under the MC standard:
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Physical Exam
I. Skin and appendages
1. Irritated or broken skin
2. Jaundice
3. Clubbing cyanosis, edema
4. Capillary refill time
5. Pallor
II. Head
1. Facial deformities
2. Scars
3. Hair growth
III. Eyes
1. Scleral icterus
2. Corneal arcus
3. Pupillary size and response
4. Fundoscopic exam
IV. Chest
1. Standard exam
V. Heart
1. Standard exam
2. Jugular vein distension
3. Peripheral pulses
VI. Abdomen
1. Liver span
VII. Nervous System
1. Complete standard neurologic exam
VIII. Laboratory
1. Hemoglobin and hematocrit
2. Alanine aminotransferase (ALT, SGPT)
3. Post-shift carboxyhemoglobin
IX. Studies
1. Pulmonary function testing
2. Electrocardiogram
An evaluation of the oxygen carrying capacity of the blood of
employees (for example by measured red blood cell volume) is considered
useful, especially for workers acutely exposed to MC.
It is also recommended, but not required, that end of shift
carboxyhemoglobin levels be determined periodically, and any level above
3% for non-smokers and above 10% for smokers should prompt an
investigation of the worker and his workplace. This test is recommended
because MC is metabolized to CO, which combines strongly with
hemoglobin, resulting in a reduced capacity of the blood to transport
oxygen in the body. This is of particular concern for cigarette smokers
because they already have a diminished hemoglobin capacity due to the
presence of CO in cigarette smoke.
C. Additional Examinations and Referrals
1. Examination by a Specialist
When a worker examination reveals unexplained symptoms or signs
(i.e. in the physical examination or in the laboratory tests), follow-up
medical examinations are necessary to assure that MC exposure is not
adversely affecting the worker's health. When the examining physician or
other licensed health care professional finds it necessary, additional
tests should be included to determine the nature of the medical problem
and the underlying cause. Where relevant, the worker should be sent to a
specialist for further testing and treatment as deemed necessary.
The final rule requires additional investigations to be covered and
it also permits physicians or other licensed health care professionals
to add appropriate or necessary tests to improve the diagnosis of
disease should such tests become available in the future.
2. Emergencies
The examination of workers exposed to MC in an emergency should be
directed at the organ systems most likely to be affected. If the worker
has received a severe acute exposure, hospitalization may be required to
assure proper medical intervention. It is not possible to precisely
define ``severe,'' but the physician or other licensed health care
professional's judgement should not merely rest on hospitalization. If
the worker has suffered significant conjunctival, oral, or nasal
irritation, respiratory distress, or discomfort, the physician or other
licensed health care professional should instigate appropriate follow-up
procedures. These include attention to the eyes, lungs and the
neurological system. The frequency of follow-up examinations should be
determined by the attending physician or other licensed health care
professional. This testing permits the early identification essential to
proper medical management of such workers.
D. Employer Obligations
The employer is required to provide the responsible physician or
other licensed health care professional and any specialists involved in
a diagnosis with the following information: a copy of the MC standard
including relevant appendices, a description of the affected employee's
duties as they relate to his or her exposure to MC; an estimate of the
employee's exposure including duration (e.g., 15hr/wk, three 8-hour
shifts/wk, full time); a description of any personal protective
equipment used by the employee, including respirators; and the results
of any previous medical determinations for the affected employee related
to MC exposure to the extent that this information is within the
employer's control.
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E. Physicians' or Other Licensed Health Care Professionals' Obligations
The standard requires the employer to ensure that the physician or
other licensed health care professional provides a written statement to
the employee and the employer. This statement should contain the
physician's or licensed health care professional's opinion as to whether
the employee has any medical condition placing him or her at increased
risk of impaired health from exposure to MC or use of respirators, as
appropriate. The physician or other licensed health care professional
should also state his or her opinion regarding any restrictions that
should be placed on the employee's exposure to MC or upon the use of
protective clothing or equipment such as respirators. If the employee
wears a respirator as a result of his or her exposure to MC, the
physician or other licensed health care professional's opinion should
also contain a statement regarding the suitability of the employee to
wear the type of respirator assigned. Furthermore, the employee should
be informed by the physician or other licensed health care professional
about the cancer risk of MC and about risk factors for heart disease,
and the potential for exacerbation of underlying heart disease by
exposure to MC through its metabolism to carbon monoxide. Finally, the
physician or other licensed health care professional should inform the
employer that the employee has been told the results of the medical
examination and of any medical conditions which require further
explanation or treatment. This written opinion must not contain any
information on specific findings or diagnosis unrelated to employee's
occupational exposures.
The purpose in requiring the examining physician or other licensed
health care professional to supply the employer with a written opinion
is to provide the employer with a medical basis to assist the employer
in placing employees initially, in assuring that their health is not
being impaired by exposure to MC, and to assess the employee's ability
to use any required protective equipment.
Appendix C to Section 1910.1052--Questions and Answers--Methylene
Chloride Control in Furniture Stripping
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[62 FR 1601, Jan. 10, 1997, as amended at 62 FR 42667, Aug. 8, 1997; 62
FR 54383, Oct. 20, 1997; 62 FR 66277, Dec. 18, 1997; 63 FR 1295, Jan. 8,
1998; 63 FR 20099, Apr. 23, 1998; 63 FR 50729, Sept. 22, 1998]
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