[Code of Federal Regulations]
[Title 49, Volume 2]
[Revised as of October 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR173.115]
[Page 506-508]
TITLE 49--TRANSPORTATION
CHAPTER I--PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION,
DEPARTMENT OF TRANSPORTATION
PART 173_SHIPPERS_GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS--
Subpart D_Definitions Classification, Packing Group Assignments and
Exceptions for Hazardous Materials Other Than Class 1 and Class 7
Sec. 173.115 Class 2, Divisions 2.1, 2.2, and 2.3--Definitions.
Source: Amdt. 173-224, 55 FR 52634 Dec. 21, 1990, unless otherwise
noted.
(a) Division 2.1 (Flammable gas). For the purpose of this
subchapter, a flammable gas (Division 2.1) means any material which is a
gas at 20 [deg]C (68 [deg]F) or less and 101.3 kPa (14.7 psia) of
pressure (a material which has a boiling point of 20 [deg]C (68 [deg]F)
or less at 101.3 kPa (14.7 psia)) which--
(1) Is ignitable at 101.3 kPa (14.7 psia) when in a mixture of 13
percent or less by volume with air; or
(2) Has a flammable range at 101.3 kPa (14.7 psia) with air of at
least 12 percent regardless of the lower limit. Except for aerosols, the
limits specified in paragraphs (a)(1) and (a)(2) of this section shall
be determined at 101.3 kPa (14.7 psia) of pressure and a temperature of
20 [deg]C (68 [deg]F) in accordance with the ASTM E681-85, Standard Test
Method for Concentration Limits of Flammability of Chemicals or other
equivalent method approved by the Associate Administrator. The
flammability of aerosols is determined by the tests specified in Sec.
173.115 (k) of this section.
(b) Division 2.2 (non-flammable, nonpoisonous compressed gas--
including compressed gas, liquefied gas, pressurized cryogenic gas,
compressed gas in solution, asphyxiant gas and oxidizing gas). For the
purpose of this subchapter, a non-flammable, nonpoisonous compressed gas
(Division 2.2) means any material (or mixture) which--
(1) Exerts in the packaging an absolute pressure of 280 kPa (40.6
psia) or greater at 20 [deg]C (68 [deg]F), and
(2) Does not meet the definition of Division 2.1 or 2.3.
(c) Division 2.3 (Gas poisonous by inhalation). For the purpose of
this subchapter, a gas poisonous by inhalation (Division 2.3) means a
material which is a gas at 20 [deg]C (68 [deg]F) or less and a
[[Page 507]]
pressure of 101.3 kPa (14.7 psia) (a material which has a boiling point
of 20 [deg]C (68 [deg]F) or less at 101.3 kPa (14.7 psia)) and which--
(1) Is known to be so toxic to humans as to pose a hazard to health
during transportation, or
(2) In the absence of adequate data on human toxicity, is presumed
to be toxic to humans because when tested on laboratory animals it has
an LC50 value of not more than 5000 mL/m\3\ (see Sec.
173.116(a) of this subpart for assignment of Hazard Zones A, B, C or D).
LC50 values for mixtures may be determined using the formula in Sec.
173.133(b)(1)(i) or CGA Pamphlet P-20 (IBR, see Sec. 171.7 of this
subchapter).
(d) Non-liquefied compressed gas. A gas, which when packaged under
pressure for transportation is entirely gaseous at -50 [deg]C (-58
[deg]F) with a critical temperature less than or equal to -50 [deg]C (-
58 [deg]F), is considered to be a non-liquefied compressed gas.
(e) Liquefied compressed gas. A gas, which when packaged under
pressure for transportation is partially liquid at temperatures above -
50 [deg]C (-58 [deg]F), is considered to be a liquefied compressed gas.
A liquefied compressed gas is further categorized as follows:
(1) High pressure liquefied gas which is a gas with a critical
temperature between -50 [deg]C (-58 [deg]F) and + 65 [deg]C (149
[deg]F), and
(2) Low pressure liquefied gas which is a gas with a critical
temperature above + 65 [deg]C (149 [deg]F).
(f) Compressed gas in solution. A compressed gas in solution is a
non-liquefied compressed gas which is dissolved in a solvent.
(g) Cryogenic liquid. A cryogenic liquid means a refrigerated
liquefied gas having a boiling point colder than -90 [deg]C (-130
[deg]F) at 101.3 kPa (14.7 psia) absolute. A material meeting this
definition is subject to requirements of this subchapter without regard
to whether it meets the definition of a non-flammable, non-poisonous
compressed gas in paragraph (b) of this section.
(h) Flammable range. The term flammable range means the difference
between the minimum and maximum volume percentages of the material in
air that forms a flammable mixture.
(i) Service pressure. The term service pressure means the authorized
pressure marking on the packaging. For example, for a cylinder marked
``DOT 3A1800'', the service pressure is 12410 kPa (1800 psig).
(j) Refrigerant gas or Dispersant gas. The terms Refrigerant gas and
Dispersant gas apply to all nonpoisonous refrigerant gases; dispersant
gases (fluorocarbons) listed in Sec. 172.101 of this subchapter and
Sec. Sec. 173.304, 173.314(c), 173.315(a), and 173.315(h) and mixtures
thereof; and any other compressed gas having a vapor pressure not
exceeding 260 psia at 54 [deg]C(130 [deg]F), used only as a refrigerant,
dispersant, or blowing agent.
(k) The following applies to aerosols (see Sec. 171.8 of this
subchapter):
(1) An aerosol must be assigned to Division 2.1 if the contents
include 85% by mass or more flammable components and the chemical heat
of combustion is 30 kJ/g or more;
(2) An aerosol must be assigned to Division 2.2 if the contents
contain 1% by mass or less flammable components and the heat of
combustion is less than 20 kJ/g.
(3) Aerosols not meeting the provisions of paragraphs (a) or (b) of
this section must be classed in accordance with the appropriate tests of
the UN Manual of Tests and Criteria (IBR, see Sec. 171.7 of this
subchapter). An aerosol which was tested in accordance with the
requirements of this subchapter in effect on December 31, 2005 is not
required to be retested.
(4) Division 2.3 gases may not be transported in an aerosol
container.
(5) When the contents are classified as Division 6.1 or Class 8, PG
III, the aerosol must be assigned a subsidiary hazard of Division 6.1 or
Class 8.
(6) Substances of Division 6.1, PG I or II, and substances of Class
8, PG I are forbidden from transportation in an aerosol container.
(7) Flammable components are Class 3 flammable liquids, Class 4.1
flammable solids, or Division 2.1 flammable gases. The chemical heat of
combustion must be determined in accordance
[[Page 508]]
with the UN Manual of Tests and Criteria (IBR, see Sec. 171.7 of this
subchapter).
[Amdt. 173-224, 55 FR 52634, Dec. 21, 1990, as amended at 56 FR 66268,
Dec. 20, 1991; 57 FR 45461, Oct. 1, 1992; Amdt. 173-236, 58 FR 50236,
Sept. 24, 1993; Amdt. 173-234, 58 FR 51532, Oct. 1, 1993; Amdt. 173-241,
59 FR 67506, Dec. 29, 1994; Amdt. 173-255, 61 FR 50625, Sept. 26, 1996;
66 FR 45379, 45380, 45382, Aug. 28, 2001; 67 FR 51642, Aug. 8, 2002; 67
FR 16013, Sept. 27, 2002; 68 FR 45033, July 31, 2003; 68 FR 75742, Dec.
31, 2003; 69 FR 76155, Dec. 20, 2004; 70 FR 34398, June 14, 2005]