The proposals will now be published in the Federal Register, triggering a 60-day period for members of the public to offer comments. A final rule must then be adopted no more than 18 months after the Federal Register publication.

PIP (3:1) and 2,4,6-TTBP were among five chemicals that the agency designated as persistent, bioaccumulative and toxic under the Frank R. Lautenberg Chemical Safety for the 21st Century Act, the nations primary chemicals management regulation. Persistent refers to substances that resist degradation in the environment, and bioaccumulative refers to those that tend to build up in animals, especially in large predators and animals that consume fish.

The EPA first flagged 2,4,6-TTBP, PIP (3:1) and the other three chemicals as PBT substances in 2016. Under the Lautenberg Act, which was enacted that year to replace the former Toxic Substances and Control Act, the five were fast-tracked for action without the performance of risk evaluations.

According to EPA, only one company – which it did not identify – manufactures or imports 2,4,6-TTBP to the U.S. The agency cited a list of products that contain the chemical, from Champion Engine Oil Additive to a Durad-branded liquid antioxidant supplied by Chemtura and a large number of fuel additives.

Studies indicate that 2,4,6-TTBP is toxic to aquatic plants, aquatic invertebrates, and fish and that it may cause liver damage and development problems in animals. The agency recommended a prohibition on the use of 2,4,6-TTBP as lubricant or fuel additives. It also proposed banning the packaging of the chemical in containers smaller than 55-gallon drums based on the idea that consumers and small commercial operators buy the chemical in smaller volumes to inject into fuels or lubricants.

PIP (3:1), which is a family of phosphate esters, is used in a variety of applications, including lubricants, where it provides both lubricity and flame retardancy. Products containing it range from ExxonMobil‘s Hyjet-branded aviation hydraulic fluids and Braycote-branded grease from Castrol to a Shell bearing lubricant and a military weapons cleaner, penetrating oil and lubricant from Nyco.

PIP (3:1) is deemed toxic to aquatic plants, aquatic invertebrates, sediment invertebrates and fish. Data indicate it may interfere with reproduction and development and could also cause damage to neurological systems and organs such as adrenals, livers, ovaries, hearts and lungs.

While the agency proposes prohibiting the use of 2,4,6-TTBP in lubricants, it specifically recommends allowing continued use of PIP (3:1) in key lubricant applications.