Aqueous solutions of alcohol transported by air and vessel
Pipeline and Hazardous Materials Safety Administration · Feb 12, 2007 · Reference No. 06-0191
Interprets: 49 CFR § 173.150, 49 CFR § 173.150(e), 49 CFR § 173.150(f)
Reggie’s quick take
A company that ships a product asked whether its alcohol solution qualifies for the exception in § 173.150(e). The product is about 10% isopropyl alcohol and more than 75% water, plus a nonhazardous surfactant, and it has a 104° F flash point. The agency said the solution meets § 173.150(e), so it is not subject to the HMR for any mode of transport. It also said that if the shipper uses the § 173.150(f) exception instead, air and vessel transport are not allowed unless other means are impracticable.
Written by AI (Claude) on Oct 22, 2026. Robots make mistakes and leave things out, so the letter below is what counts. Not legal advice.
This responds to your August 28, 2006 letter requesting clarification on the applicability of the exception for aqueous solutions of alcohol in § 173.150(e) under the Hazardous Materials Regulations (HMR; 49 CFR Parts 17 1-180). Specifically, you ask whether the alcohol solution you ship meets the provisions in § 173.150(e), and whether §173.150(f) has any impact on your shipment if transported by aircraft or vessel.
According to your letter, your client ships a product containing 10% Isopropyl Alcohol with greater than 75% water with a second ingredient, "Nonylphenoxy poly (etheleneoxy) ethanol," a nonionic surfactant-alkylphenol ethoxylate (NPE), which is not a hazardous material under the HMR. This product has a flash point of 104° F, contains no other hazardous materials, and is packaged in a 2.75 gallon container.
According to §173.150(e), an aqueous solution of alcohol maybe reclassed as a combustible liquid, and is not subject to the HMR when it contains 24% or less alcohol by volume, no other hazardous material, and more than 50% water. Based on the information provided in your letter, it is the opinion of this Office that your alcohol solution does meet the provisions in §173.150(e) as an aqueous solution of alcohol, and is not subject to the HMR when transported by all modes. However, if you choose to use the exception in § 173.150(f), transportation by aircraft or vessel is not authorized except where other means of transportation is impracticable.
I hope this answers your inquiry.
A letter of interpretation applies the regulations to the facts the requester described. It isn’t a regulation and isn’t legal advice. The agency’s copy.