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Interpretation Response #05-0131 ([Holman Fenwick & William] [Mr. Rory Butler])

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

Interpretation Response Details

Response Publish Date:

Company Name: Holman Fenwick & William

Individual Name: Mr. Rory Butler

Country: UK

View the Interpretation Document

Response text:

Oct 12, 2005

Mr. Rory Butler                    Reference No. 05-0131

Holman Fenwick & William

Marlow House, Lloyds Avenue

London, EC3N 3AL

Dear Mr. Butler:

This is in response to your e-mail dated May 18, 2005 requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to Calcium hypochlorite, dry (UN1748). Specifically, you ask for the permissible moisture content of "Calcium hypochlorite, dry" (UN1748).

The HMR do not specifically address the permissible moisture content of Calcium hypochlorite, dry. However, as your email notes, Calcium hypochlorite, hydrated (1JN2880) has a specific range of not less than 5.5 percent but not more than 16 percent water. Therefore, the moisture content of Calcium hypochlorite may not exceed 5.5 percent in order for the material to be classed as "Calcium hypochlorite, dry."

I hope this information is helpful.


John A. Gale

Chief, Standards Development

Office of Hazardous Materials Standards


Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table