[Code of Federal Regulations]
[Title 49, Volume 2]
[Revised as of October 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR173.125]

[Page 480-481]
 
                        TITLE 49--TRANSPORTATION
 
 CHAPTER I--RESEARCH AND SPECIAL PROGRAMS ADMINISTRATION, DEPARTMENT OF 
                             TRANSPORTATION
 
PART 173--SHIPPERS--GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS--Table of Contents
 
  Subpart D--Definitions Classification, Packing Group Assignments and 
    Exceptions for Hazardous Materials Other Than Class 1 and Class 7
 
Sec. 173.125  Class 4--Assignment of packing group.

    (a) The packing group of a Class 4 material is assigned in column 
(5) of the Sec. 172.101 table. When the Sec. 172.101 table provides more 
than one packing group for a hazardous material, the packing group shall 
be determined on the basis of test results following test methods given 
in the UN Manual of Tests and Criteria and by applying the appropriate 
criteria given in this section.
    (b) Packing group criteria for readily combustible materials of 
Division 4.1 are as follows:
    (1) Powdered, granular or pasty materials must be classified in 
Division 4.1 when the time of burning of one or more of the test runs, 
in accordance with the UN Manual of Tests and Criteria, is less than 45 
seconds or the rate of burning is more than 2.2 mm/s. Powders of metals 
or metal alloys must be classified in Division 4.1 when they can be 
ignited and the reaction spreads over the whole length of the sample in 
10 minutes or less.
    (2) Packing group criteria for readily combustible materials of 
Division 4.1 are assigned as follows:
    (i) For readily combustible solids (other than metal powders), 
Packing Group II if the burning time is less than 45 seconds and the 
flame passes the wetted zone. Packing Group II must be assigned to 
powders of metal or metal alloys if the zone of reaction spreads over 
the whole length of the sample in 5 minutes or less.
    (ii) For readily combustible solids (other than metal powders), 
Packing

[[Page 481]]

Group III must be assigned if the burning rate time is less than 45 
seconds and the wetted zone stops the flame propagation for at least 4 
minutes. Packing Group III must be assigned to metal powders if the 
reaction spreads over the whole length of the sample in more than 5 
minutes but not more than 10 minutes.
    (c) Packing group criteria for Division 4.2 materials is as follows:
    (1) Pyrophoric liquids and solids of Division 4.2 are assigned to 
Packing Group I.
    (2) A self-heating material is assigned to--
    (i) Packing Group II, if the material gives a positive test result 
when tested with a 25 mm cube size sample at 140  deg.C; or
    (ii) Packing Group III, if--
    (A) A positive test result is obtained in a test using a 100 mm 
sample cube at 140  deg.C and a negative test result is obtained in a 
test using a 25 mm sample cube at 140  deg.C and the substance is 
transported in packagings with a volume of more than 3 cubic meters; or
    (B) A positive test result is obtained in a test using a 100 mm 
sample cube at 120  deg.C and a negative result is obtained in a test 
using a 25 mm sample cube at 140  deg.C and the substance is transported 
in packagings with a volume of more than 450 L; or
    (C) A positive result is obtained in a test using a 100 mm sample 
cube at 100  deg.C and a negative result is obtained in a test using a 
25 mm sample cube at 140  deg.C and the substance is transported in 
packagings with a volume of less than 450 L.
    (d) A Division 4.3 dangerous when wet material is assigned to--
    (1) Packing Group I, if the material reacts vigorously with water at 
ambient temperatures and demonstrates a tendency for the gas produced to 
ignite spontaneously, or which reacts readily with water at ambient 
temperatures such that the rate of evolution of flammable gases is equal 
or greater than 10 L per kilogram of material over any one minute;
    (2) Packing Group II, if the material reacts readily with water at 
ambient temperatures such that the maximum rate of evolution of 
flammable gases is equal to or greater than 20 L per kilogram of 
material per hour, and which does not meet the criteria for Packing 
Group I; or
    (3) Packing Group III, if the material reacts slowly with water at 
ambient temperatures such that the maximum rate of evolution of 
flammable gases is greater than 1 L per kilogram of material per hour, 
and which does not meet the criteria for Packing Group I or II.

[Amdt. 173-224, 55 FR 52634 Dec. 21, 1990, as amended by Amdt. 173-255, 
61 FR 50625, Sept. 26, 1996; Amdt. 173-261, 62 FR 24731, May 6, 1997; 62 
FR 51560, Oct. 1, 1997; 66 FR 45380, Aug. 28, 2001]