On November 17th, 2016 I requested an interpretation from the DOT on the domestic hazardous materials regulations (HMR) limited quantity variance from the ICAO Technical Instructions which made no allowance for offering Nitrate film as a limited quantity (see LOI-16-0195). Well, they finally made the modifications, effective December 28th 2020 and now allows shipments of Nitrate film to be shipped by ground as limited quantities.

These changes to the HMR apply solely to UN1324 offered for transportation and/or transported anywhere to, from, or through the U.S. However, the changes to the Limited Quantity exception were done, at least in part, to harmonize the HMR with existing international regulations. Therefore, the relief from regulation offered by this Final Rule already exist in the international regulations of the following:

• International Civil Aviation Org. (ICAO) & International Air Transport Assoc. (IATA)

• International Maritime Org. (IMO)

DOT’s PHMSA has revised Column (8A) (exception 173.151) of the HMT which is now consistent with the UN Model Regulations to allow UN1324 to be shipped as limited quantities under the HMR.

Here's the details.

§173.151 Exceptions for Class 4.

(a) General. Exceptions for hazardous materials shipments in the following paragraphs are permitted only if this section is referenced for the specific hazardous material in the §172.101 table of this subchapter.

(b) Limited quantities of Division 4.1.

(1) Limited quantities of flammable solids (Division 4.1) in Packing Groups II and III and, where authorized by this section, charcoal briquettes (Division 4.2) in Packing Group III, are excepted from labeling requirements unless the material is offered for transportation or transported by aircraft, and are excepted from the specification packaging requirements of this subchapter when packaged in combination packagings according to this paragraph. If authorized for transportation by aircraft, the package must also conform to applicable requirements of §173.27 of this part (e.g., authorized materials, inner packaging quantity limits and closure securement) and only hazardous material authorized aboard passenger-carrying aircraft may be transported as a limited quantity. A limited quantity package that conforms to the provisions of this section is not subject to the shipping paper requirements of subpart C of part 172 of this subchapter, unless the material meets the definition of a hazardous substance, hazardous waste, marine pollutant, or is offered for transportation and transported by aircraft or vessel, and is eligible for the exceptions provided in §173.156 of this part. In addition, shipments of limited quantities are not subject to subpart F (Placarding) of part 172 of this subchapter. Each package must conform to the packaging requirements of subpart B of this part and may not exceed 30 kg (66 pounds) gross weight. Except for transportation by aircraft, the following combination packagings are authorized:

(i) PG I…

(ii) PG II…

(ii) For flammable solids in Packing Group III, inner packagings not over 5.0 kg (11 pounds) or 5.0 L (1.3 gallon) net capacity each, packed in a strong outer packaging.

In summary, this provides ground shipments of nitrate a lot of relief.

With only the black tipped, limited quantity marking domestic shippers in the US no longer need the following:

• The red & white striped hazard label Div. 4.1;
• UN packaging, provided they use strong outer packaging capable of the 1.2 M drop test;
• Shipping papers
• Placards