EPA Revises Hazardous Waste Flashpoint Determination Test

Written July 7, 2020

Categories: First to Know

Beginning September 8, 2020, the U.S. Environmental Protection Agency’s (EPA) new rule for determining if a waste is considered hazardous due to its flashpoint takes effect. EPA’s primary reason for revising the test is to update and modernize it to allow other approaches for measuring temperature other than the mandated use of mercury thermometers.

Under EPA’s hazardous waste regulations, solid wastes are classified and regulated as hazardous wastes if they are specifically identified or “listed” or if they exhibit a “characteristic” property of hazardous waste. One of the characteristics is ignitability, which has different criteria for classifying wastes as hazardous, depending on whether they are solids, liquids, or gases. Liquids that have flash points below 60°C (140°F) are classified as ignitable hazardous wastes. There is one exception and that is for aqueous liquids with less than 24% alcohol.

EPA’s revised rule addresses how the flashpoint of liquids is to be determined. It allows the use of alternative test methods for determining the flashpoints of liquids (e.g., methods that use non-mercury temperature measuring devices, electric spark ignition sources rather than flame ignition sources, and automated instrumentation). In addition, the final rule modifies the criteria for ignitable compressed gases and oxidizers to track the corresponding definitions in the U.S. Department of Transportation (DOT) Hazardous Materials Regulations more closely.

In EPA’s proposal to revise the regulation, it considered narrowing the exclusion for aqueous liquids with less than 24% alcohol. In the final rule, EPA modified the exclusion so that it now applies to “solution(s) containing less than 24 percent alcohol by volume and at least 50 percent water by weight” rather than stating “aqueous liquids with less than 24% alcohol”. According to EPA, this change is consistent with long-standing guidance on the meaning of an “aqueous solution”.

EPA had also proposed new requirements to address multi-phased liquids and separate flashpoint determination requirements for each phase. In the final rule, EPA decided not to finalize its proposal on multiphase wastes. Instead, EPA will rely upon previous guidance to explain the Agency’s position on the status of multiphase wastes.

Even though the rule becomes effective on September 8, 2020, it is not universally applicable across all state and local hazardous waste programs. Virtually all states have their own hazardous waste regulatory programs. The changes to the ignitability characteristic will not take effect in these states until the changes are adopted by each state. Because the changes are more technical and not more stringent than the existing rule, states will not be required to adopt the changes. Nevertheless, because of the technical nature of the final rule, it seems likely that states will gradually adopt the new rule over time.

For more information, please contact PrUA’ s Government Affairs team at govtaffairs@sgia.org.