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Interpretation Response #22-0083

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

Interpretation Response Details

Response Publish Date:

Company Name: Pilot Chemical Company

Individual Name: Megan O’Connor

Location State: OH Country: US

View the Interpretation Document

Response text:

November 4, 2022

Ms. Megan O'Connor
EHS Contractor
Pilot Chemical Company
9075 Centre Pointe Dr., Suite 400
West Chester, OH  45069

Reference No. 22-0083

Dear Ms. O'Connor:

This letter is in response to your August 12, 2022, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the shipping description for organic peroxide formulations. Specifically, for a hazardous material classified as "UN3109, Organic peroxide type F, liquid, 5.2" you ask whether a concentration is required to be included in association with the technical name for "Peroxyacetic acid, type F, stabilized" as listed in the § 173.225(c) organic peroxide table. You state your belief that the addition of a concentration (i.e., ≤ 43%) for this organic peroxide formulation would be redundant because any shipment using that technical name as part of the hazardous materials description would by definition contain no more than 43% peroxyacetic acid.

The answer is no. The organic peroxide concentration is only required to be included with the technical name for organic peroxides which may qualify for more than one generic listing. For such instances, the technical name must include the actual concentration being shipped or the concentration range for the appropriate generic listing. For example, "UN3102, Organic peroxide type B, solid, 5.2, (dibenzoyl peroxide, 52-100%)" or "UN3108, Organic peroxide type E, solid, 5.2, (dibenzoyl peroxide, paste, <52%)". See § 172.203(k). Finally, please note that, while you are not required to indicate that the concentration of peroxyacetic acid is no more than 43%, including the concentration in association with the technical name would not be prohibited.

I hope this information is helpful. Please contact us if we can be of further assistance.


Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division

172.203(k), 173.225(c)

Regulation Sections

Section Subject
172.203 Additional description requirements
173.225 Packaging requirements and other provisions for organic peroxides