§173.133. Assignment of packing group and hazard zones for Division 6.1 materials. — Inbound Citations

(b) The criteria specified in paragraph (a) of this section are represented graphically in § 173.133, Figure 1.

Division 6.1, Packing Group I, Zone A poisonous by inhalation (see § 173.133) must be packed in non-bulk packagings in accordance with the following paragraphs:

(5) This section does not apply to a hazardous material that is self-reactive (see § 173.124), poisonous by inhalation (see § 173.133), or a hazardous waste.

(3) The values of yield strength or proof strength must be the values according to recognized material standards. When austenitic steels are used, the specified minimum values of yield strength or proof strength according to the material standards may be increased by up to 15% for portable tanks used for liquid and solid hazardous materials, other than toxic by inhalation liquids meeting the criteria of Hazard Zone A or Hazard Zone B (see § 173.133 of this subchapter), when these greater values are attested in the material inspection certificate.

(iii) Any quantity of a poison inhalation hazard Zone A or B material as defined in § 173.115, § 173.132, or § 173.133 of this title.

(3) More than one L (1.06 quarts) per package of a material extremely toxic by inhalation (i.e., “material poisonous by inhalation,” as defined in § 171.8 of this chapter, that meets the criteria for “hazard zone A,” as specified in § 173.116(a) or § 173.133(a) of this chapter);

(2) A maximum net mass greater than 400 kg (882 pounds) and a maximum capacity greater than 450 L (119 gallons) as a receptacle for a solid; or

(c) More than one liter (1.08 quarts) per package of a “material poisonous by inhalation,” as defined in § 171.8 of this title, that meets the criteria for “hazard zone A,” as specified in § 173.116(a) or § 173.133(a) of this title;

(2) Is capable of promptly responding to unauthorized access or activity at or near the rail car, including immediately contacting law enforcement or other authorities; and

(c) For purposes of classifying and assigning packing groups to mixtures possessing oral or dermal toxicity hazards according to the criteria in § 173.133(a)(1), it is necessary to determine the acute LD50 of the mixture. If a mixture contains more than one active constituent, one of the following methods may be used to determine the oral or dermal LD50 of the mixture:

(1) Obtain reliable acute oral and dermal toxicity data on the actual mixture to be transported;

(2) If reliable, accurate data is not available, classify the formulation according to the most hazardous constituent of the mixture as if that constituent were present in the same concentration as the total concentration of all active constituents; or

(3) If reliable, accurate data is not available, apply the formula:

(a) The provisions of this section apply only to materials extremely poisonous by inhalation which are Division 2.3 materials in Hazard Zone A and Division 6.1 materials in Hazard Zone A, as defined in § 173.133(a)(2) of this subchapter. Such materials when shipped by, for, or to the Department of Defense may be transported by rail only if loaded and handled in accordance with the requirements of this section.

A tank car containing a material extremely poisonous by inhalation which is a Division 2.3 material in Hazard Zone A or a Division 6.1 material in Hazard Zone A, as defined in § 173.133(a)(2) of this subchapter, may not be transported by rail unless it is originally consigned or subsequently reconsigned to a party having a private track on which it is to be delivered and unloaded (see § 171.8 of this subchapter) or to a party using railroad siding facilities which are equipped for piping the liquid or gas from the tank car to permanent storage tanks or sufficient capacity to receive the entire contents of the car. See the requirements in § 174.290 for materials extremely poisonous by inhalation which are shipped by, for, or to the Department of Defense.

(3) LC50 for acute toxicity on inhalation means that concentration of vapor, mist, or dust which, administered by continuous inhalation for one hour to both male and female young adult albino rats, causes death within 14 days in half of the animals tested. If the material is administered to the animals as a dust or mist, more than 90 percent of the particles available for inhalation in the test must have a diameter of 10 microns or less if it is reasonably foreseeable that such concentrations could be encountered by a human during transport. The result is expressed in mg/L of air for dusts and mists or in mL/m 3 of air (parts per million) for vapors. See § 173.133(b) for LC50 determination for mixtures and for limit tests.

(i) When provisions of this subchapter require the use of the LC50 for acute toxicity on inhalation of dusts and mists based on a one-hour exposure and such data is not available, the LC50 for acute toxicity on inhalation based on a four-hour exposure may be multiplied by four and the product substituted for the one-hour LC50 for acute toxicity on inhalation.

(ii) When the provisions of this subchapter require the use of the LC50 for acute toxicity on inhalation of vapors based on a one-hour exposure and such data is not available, the LC50 for acute toxicity on inhalation based on a four-hour exposure may be multiplied by two and the product substituted for the one-hour LC50 for acute toxicity on inhalation.

(iii) A solid substance should be tested if at least 10 percent of its total mass is likely to be dust in a respirable range, e.g. the aerodynamic diameter of that particle-fraction is 10 microns or less. A liquid substance should be tested if a mist is likely to be generated in a leakage of the transport containment. In carrying out the test both for solid and liquid substances, more than 90% (by mass) of a specimen prepared for inhalation toxicity testing must be in the respirable range as defined in this paragraph (b)(3)(iii).

(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 § 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 § 173.133(b)(1)(i) or CGA P-20 (IBR, see § 171.7 of this subchapter).