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Interpretation Response #04-0161 ([URS Corporation] [Mr. Andrew N. Romach])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: URS Corporation

Individual Name: Mr. Andrew N. Romach

Location State: NC Country: US

View the Interpretation Document

Response text:

Feb 11, 2004


Mr. Andrew N. Romach                 Reference No. 04-0161
Corporate Regulatory Manager
URS Corporation
1600 Perimeter Park Drive
Morrisville, NC 27560

Dear Mr. Romach:

This responds to your letter requesting our assistance in determining the correct shipping description for a metal powder, which meets the definition of a flammable solid, when suspended in a flammable liquid under the Hazardous Materials Regulations (HMR; 49 CFR Parts. 171-180) . You posed a scenario of a material, Aluminum powder coated, 4.1, UN1309, PG II, suspended in a flammable liquid (solvent) mixture that has a flash point of about 63°F (Class 3, PG II) . It is your understanding that there are no proper shipping names listed in the § 172.101 Hazardous Materials Table (HMT) for these mixtures except for Zirconium suspended in a liquid, tJN1308. I apologize for the delay in responding and any inconvenience it may have caused.

You are correct that no specific or generic description for your material currently exists in the HMT. In your scenario, provided the aluminum powder is compatible with the flammable liquid in your mixture and the overall mixture does not meet the definition of another hazard class, it is our opinion that it should be described as. “Flammable liquids, n.o.s. (1-methoxy-2- propyl acetate, Xylene), 3, UN1993, PG II.” We anticipate proposing generic descriptions in the HMT for scenarios such as yours in a future rulemaking.

I trust this satisfies your inquiry. Please contact us if we can be of further assistance.



Hattie L. Mitchell
Chief, Regulatory Review and Reinvention
Office of Hazardous Materials Standards


Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table