EPA Evaluates Antiwear Agent


A chemical used as an antiwear additive in aviation turbine oils was among 20 chemicals listed by the United States Environmental Protection Agency this month as high priorities for risk evaluation under the Toxic Substances Control Act.

The announcement signals that the agency could eventually restrict use of triphenyl phosphate or imposing new rules about how it is handled and communication of hazards that it may pose.

In its Sept. 4 announcement, EPA noted that the chemical, also known as TPP, is used as an antiwear agent in lubricants for jet turbine engines as well as turbines used for other applications such as power generation and marine engines. TPP is also used in other lubricants, such as those used to maintain construction cranes.

The list also included two other substances with more limited use in lubricants, including p-dichlorobenzene; and 1,2 dichloroethane.

TPP is a colorless solid used primarily as a flame retardant.  According to the National Institutes of Health’s PubChem database, it is classified as hazardous to the environment because it is very toxic to aquatic life with long-lasting impacts. EPA said it is concerned that levels of the chemical detected in the environment have been rising.

EPA is scheduled to complete its evaluations of the 20 chemicals by Dec. 20, 2022 but may extend that period by six months. The agency began evaluating high priority chemicals after Congress amended TSCA to give EPA more power to regulate chemicals.

The agency began with a batch of 10 chemicals that included formaldehyde – of interest to the lubricants industry because a number of agents that release formaldehyde are used as biocides in metalworking fluids. Since December of last year, EPA is required to always be evaluating 20 chemicals.