The United States Department of Transportation Pipeline and Hazardous Materials Safety Administration (“PHMSA”) responded to a request from Patterson Companies, Inc. (“Patterson”) addressing the Hazardous Materials Regulations (“HMR”) classification of Soda lime.

Patterson’s query described Soda lime as being comprised of calcium hydroxide and a small concentration of sodium hydroxide and further stated:

. . .according to your manufacturers, in some scenarios soda lime may contain sodium hydroxide or potassium hydroxide in concentrations of less than 4%. You asked for verification of statements about classification and use of the HMR for international shipments.

PHMSA addressed five specific questions in its May 19th response to Patterson, Inc. which included:

Q1: You ask whether Soda lime containing less than 4% sodium hydroxide found to meet the definition of one or more hazard classes and divisions would be a hazardous material and therefore subject to the HMR.

A1: The answer is yes. The §172.102 Hazardous Materials Table (HMT) qualifies the use of shipping description “UN1907, Soda lime” with having more than 4% sodium hydroxide. Nevertheless, if a material (in this case, soda lime containing less than 4% sodium hydroxide) meets the defining criteria of one or more hazard classes, it must be shipped as a hazardous material in accordance with § 173.2(a).

Q2: You ask if Soda lime containing less than 4% sodium hydroxide that is found to meet the definition of a corrosive material (class 8), would require a generic shipping name since the material in question does not meet the qualifying concentration of sodium hydroxide for “UN1907 Soda lime.”

A2: The answer is yes. Because the proper shipping name “UN1907, Soda lime” is qualified with having a concentration of sodium hydroxide of more than 4%, the material you describe should be transported under a more specific proper shipping name. In this specific case, a generic proper shipping name would be the most accurate name to describe your material.

Q3: You ask if soda lime containing more than 4% sodium hydroxide that also meets the definition of a class 8, packing group II hazardous material, would require a generic shipping name since UN1907 Soda lime would only be eligible for soda lime containing more than 4% sodium hydroxide meeting packing group III criteria.

A3: In conformance with § 173.22 of the HMR, it is the shipper’s responsibility to properly classify a hazardous material. This Office generally does not perform this function. However, based on the information you provided it is the opinion of this Office that the material you described would be properly classified as “UN3626, Corrosive, solid, basic, inorganic, n.o.s.” instead of “UN1907, soda lime.”

Q4: You ask if “UN3262 Corrosive, solid, basic, inorganic, n.o.s.” (with the applicable technical name in parentheses) would be an appropriate proper shipping name for soda lines describe in numbers Q2 and Q3 above.

A4: The answer is yes. See A2 and A3 above.

Q5: You ask if a hazardous material subject to the HMR, but excepted from or not subject to international regulations when shipped into the United states, must comply with all applicable requirements in the HMR (classification, packaging, labeling, marking, shipping paperwork) prior to its arrival in the United States (see § 173.22 (c)).

A5: The answer is yes. Any shipment of hazardous materials transported into the United States must be in conformance with the HMR (see § 173.22 (c)).

A copy of the May 19th letter can be downloaded here.