PHMSA Response Letter

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APR 12, 2001

This responds to your January 4, 2001 letter requesting clarification on the applicability of the subsidiary labeling-requirements in § I 72.402(a) (2) to organic peroxides under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180).

Division 5.2 materials (organic peroxides) are subject to the subsidiary labeling requirements in 172.402(a)(2). Therefore, in accordance with § 172.402, a package containing a Division 5.2 material that also meets the definition of Class 3 must be labeled ORGANIC PEROXIDE and FLAMMABLE LIQUID (Note the exception in § 172.402(a)(2) for Class 3 materials in Packing Group Ill.) As you note, however, 5.2.2.1.9 of the UN Model Regulations specifies that a subsidiary FLAMMABLE LIQUID label is not required on such a package because the ORGANIC PEROXIDE label is understood to convey the inherently flammable nature of organic peroxides. We will consider addressing this inconsistency in a future rulemaking.

I hope this information is helpful. If we can be of further assistance, please contact us.

Sincerely,

Edward T. Mazzullo
Director, Office of Hazardous
  Materials Standards

172.402, 173.225(b)