Ask the Expert, Hazardous and Solid Waste, Q&A

The Headworks Exemption

Q. Does the headworks exemption at 40 CFR 261.3 (a)(2)(iv)(A) and (B) apply only to those spent solvents identified in the regulation? If you are below the threshold for the identified solvents, can other solvents be considered exempt?

A. The headworks exemption for solvents applies only to those solvents specified in the rule. The EPA chose the solvents so identified based on the Agency’s assessments of the risks that each one poses to the environment. The EPA determined that the relatively small volumes of the specified solvents can be easily and effectively handled by the wastewater treatment system so that risk to the environment is negligible. Consequently, it is unlikely that the EPA would extend the application of the hazardous waste exemption to solvents (e.g. methanol and acetone) that are not specified in the rule, regardless of whether it can be demonstrated that they and the EPA identified solvents are below the quantity threshold that is required in order to comply with the headworks exemption.

Generators have the option of petitioning EPA under 40 CFR 260.22 to exclude a waste produced at a particular facility from the definition of hazardous waste. Such petitions must demonstrate that the waste does not meet any of the criteria for which it was listed nor has other attributes that might result in the waste being hazardous.