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Interpretation Response #09-0146 ([Westinghouse Electric Company] [Mr. Michael D. Alston])

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

Interpretation Response Details

Response Publish Date:

Company Name: Westinghouse Electric Company

Individual Name: Mr. Michael D. Alston

Location State: PA Country: US

View the Interpretation Document

Response text:

August 27, 2009




Mr. Michael D. Alston

Westinghouse Electric Company

P.O. Box 355

Pittsburgh, PA 15230-0355

Ref. No. 09-0146

Dear Mr. Alston:

This responds to your June 16, 2009 letter requesting clarification of the applicability of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) to "Zirconium powder, wetted, UN1358." Specifically, it is your position that when wetted with 25 percent water or more, the material may be transported as a non-regulated material.

Your understanding is incorrect. Wetted zirconium powder with not less than 25 percent water may not be transported as a non-regulated material. Wetted zirconium powder with not less than 25 percent water is classed as a Division 4.1 material and assigned Packing Group II as specified in the § 172.101 Hazardous Materials Table (HMT) and as required by § 173.125(a). Determination of the packing group on the basis of test results following test methods provided in the UN Manual of Tests and Criteria and using the criteria provided in

§ 173.125(b) does not apply. You should be aware that the limitation to be wetted with not less than 25 percent water is a condition to suppress the pyrophoric properties of dry zirconium powder, UN2008 (i.e., zirconium powder wetted with less than 25 percent water), which is a Division 4.2 spontaneously combustible material. By designation in the HMT, wetting dry zirconium powder (with not less than 25 percent water) requires the material to be reclassed from Division 4.2 to Division 4.1.

I hope this information is helpful. If you have further questions, please do not hesitate to contact this office.


Charles E. Betts

Chief, Standards Development

Office of Hazardous Materials Standards

172.101, 173.125

Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table
173.125 Class 4-Assignment of packing group