Interpretation Response #26-0062
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: FORTREX
Individual Name: Blayze Schrepfer
Location State: AR Country: US
View the Interpretation Document
Response text:
October 6, 2026
Blayze Schrepfer
EHS Manager
FORTREX
1501 E 8th St.
North Little Rock, AR 72114
Reference No. 26-0062
Dear Mr. Schrepfer:
This letter is in response to your May 13, 2026 email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the transport of bulk materials, specifically, organic peroxides in portable tanks and residues of sodium hydroxide in cargo tanks or portable tanks.
We have paraphrased and answered your questions as follows:
Q1. Is there a 40,000 pound (18,000 kg) maximum quantity limit for transporting "UN3119, Organic Peroxide Type F, Liquid, Temperature Controlled (i.e., for peroxyacetic acid formulations) in UN portable tanks (ISO tank containers) under § 173.225?
A1. No. The HMR does not specify a general maximum quantity limit for organic peroxides contained in portable tanks. While there is not a maximum volume or weight limit for organic peroxides transported in portable tanks, the degree of filling may not exceed 90% at 15 °C, as provided in § 173.225(h)(3)(xi).
Q2. Does the HMR restrict the heel (i.e., the residue) volume to 925 gallons or any other specific amount for Sodium hydroxide solution (UN1824, Class 8 at 32-50% concentration) in cargo tanks or portable tank?
A2. No. The HMR do not specify limits for residue amounts of hazardous material allowed in a packaging. However, in accordance with § 173.29, an empty packaging containing the residue of a hazardous material must be offered for transportation and transported in the same manner as when the packaging previously contained a greater quantity of that hazardous material.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division