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Interpretation Response #23-0103

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

Interpretation Response Details

Response Publish Date:

Company Name: Logistics Specialist IV

Individual Name: Shelly Stampfler

Location State: CT Country: US

View the Interpretation Document

Response text:

March 27, 2024

Shelly Stampfler
Logistics Specialist IV
Entegris Inc.
7 Commerce Drive
Danbury, CT  06810

Reference No. 23-0103

Dear Ms. Stampfler:

This letter is in response to your December 1, 2023, email and subsequent email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to a reportable quantity (RQ). In your email, you reference a steel cylinder with a gross weight of 85 kilograms containing 21 kilograms net weight of "UN2199, Phosphine, 2.3," and you note that "Phosphine" is listed with an RQ of 45.4 kilograms in Table 1 to Appendix A of § 172.101. You ask whether the weight of the packaging combined with the weight of the hazardous substance is used to determine whether the hazardous substance meets an RQ.

The answer is no. A hazardous substance is a material listed in Appendix A of § 172.101 that is in a quantity in one package that equals or exceeds the RQ for that material listed in Appendix A to § 172.101 and—when in a mixture or solution—satisfies the applicable criteria for "hazardous substance" as defined in § 171.8. Therefore, a steel cylinder containing 21 kilograms net weight of "Phosphine" would not exceed the RQ of 45.4 kilograms listed in Table 1 to Appendix A of § 172.101 of the HMR.

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


Steven Andrews
Acting Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division

172.101, 171.8

Regulation Sections

Section Subject
171.8 Definitions and abbreviations
172.101 Purpose and use of hazardous materials table