PHMSA Response Letter

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June 9, 2011

Mr. Thomas Reese
Distribution Safety & Regulatory Compliance Consultant
DuPont Sourcing & Logistics
4417 Lancaster Pike
Barley Mill Plaza 22/2226
Wilmington, DE 19805

Ref. No.: 11-0105

Dear Mr. Reese:

This responds to your April 18, 2011 letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the definition of corrosive materials.

In your letter, you state that your company, Dupont, receives metal corrosion test results for one of its products. You indicate that the laboratory test report for the product states it is not corrosive to metals at a rate of 6.25 mm/yr, but it exhibits ¿localized corrosion¿ at the liquid/vapor interface exceeding 120 mm when exposed for seven days. You provide data in an attachment of the metal corrosion test results. You ask if a shipper is required to use both ¿uniform corrosion¿ and ¿localized corrosion¿ data when determining whether a material meets the definition of a Class 8 corrosive material based on its corrosive effects on aluminum or steel.

The answer is yes. Under the HMR, both tests must be considered when determining if a material is corrosive. It is the opinion of this Office that based on the information from the results of the tests your company performed, your material is considered a Class 8 corrosive material. (See § 173.136.)

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

Sincerely,

T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division

173.136