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Interpretation Response #08-0214 ([DuPont Global Logistics] [Mr. Kevin Greene])

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

Interpretation Response Details

Response Publish Date:

Company Name: DuPont Global Logistics

Individual Name: Mr. Kevin Greene

Location State: AL Country: US

View the Interpretation Document

Response text:

November 19, 2008

Mr. Kevin Greene

Hazardous Materials Distribution Consultant

DuPont Global Logistics

12650 Highway 43 North

Axis, AL 36505

Ref. No. 08-0214

Dear Mr. Greene:

This responds to your letter dated August 22, 2008 regarding classification of Division 4.2 self heating substances under the Hazardous Materials Regulations (HMR; 49 Parts 171-180). Specifically you asked for our concurrence concerning the technical merit of an alternative to the testing method described in the UN Manual of Tests and Criteria, 4th revised edition (UN Manual). The specific requirements you address are contained in section 33.3 of the UN Manual and are implemented through the provisions of § 173.124 of the HMR.

The UN Manual describes a Division 4.2 self-heating material as a material that, when in contact with air and without an energy supply, is liable to self-heat. A material of this type exhibits spontaneous ignition or experiences dangerous self heating described by a 60 °C rise in temperature over the oven temperature within 24 hours. The UN Manual specifies that substances with a temperature of spontaneous combustion higher than 50 °C for a volume of 27 m3 should not be assigned to Division 4.2.

The method described in the UN Manual requires testing of samples in 25 mm and 100 mm cubes at discrete temperatures to establish whether a material meets the definition of a Division 4.2 self heating material and to determine the packing group. Your alternative method utilizes a simplified self heating-model based on Frank-Kamenetskii ignition theory to extrapolate from experimentally obtained, small scale data the spontaneous ignition temperature of a given substance at a 27 m3 mass.

We have reviewed the information provided with your letter and we agree that the alternative test method you propose will accurately establish the self-ignition temperature of a solid material of a given mass consistent with the guidance provided in the UN Manual.

I hope this satisfies your inquiry. If we can be of further assistance, please contact us.



Susan Gorsky

Acting Chief, Standards Development

Office of Hazardous Materials Standards


Regulation Sections

Section Subject
173.124 Class 4, Divisions 4.1, 4.2 and 4.3-Definitions