The United States Pipeline and Hazardous Materials Safety Administration (“PHMSA”) addressed in a November 2nd letter a question requesting clarification of the Hazardous Materials Regulations (“HMR”) applicable to the exception for aqueous solutions of alcohol.

PHMSA was responding to a May 9th letter from Patterson Companies, Inc. (“Patterson”).

Patterson posed two questions.

First, the company asked whether an aqueous solution of alcohol with a small concentration of other hazardous materials is eligible for the exception in § 173.150(e)(2)?

PHMSA answers the question in the negative. The agency notes:

To qualify for the exception prescribed in § 173.150(e)(2), an aqueous solution of alcohol must contain only alcohol and no other hazardous material.

Second, Patterson asked whether a solution described as “UN1986, Alcohols, flammable, toxic, n.o.s.” contains no more than 24 percent alcohol by volume, is no less than 50 percent water, and contains no other hazardous materials, would it be eligible for the exception in § 173.150(e)(2)?

PHMSA again answers in the negative. The agency states:

The original intent of this exception was only to provide relief for alcohols that do not meet the definition of a hazard class other than Class 3 flammable liquid. When this exception was initially introduced into the HMR, the main consideration was the effect of alcohol concentration on the flashpoint of an aqueous solution. Therefore, the exception provided in § 73.150(e) is not suitable for the material described in your scenario based on the associated toxic hazard.