United States D4 Evaluation
The silicones industry worked with the US Environmental Protection Agency (EPA) to design a monitoring program to assess levels of D4 in the environment and produce exposure data the agency needed to conduct a thorough and scientifically sound risk assessment. The final results of the D4 environmental monitoring program were submitted to EPA in September 2017.
An independent peer-reviewed study of the monitoring program data concluded that D4 poses negligible risk to the environment and that no regulatory restrictions for D4 are warranted.
In February, 2020, the industry submitted its request to EPA to conduct a risk evaluation of D4 under the Toxic Substances Control Act (TSCA). In October, 2020, the industry received official notification that EPA had granted the industry request for a D4 risk evaluation. The industry has been steadfast in its support for risk-based assessments of silicone substances, including D4, and is confident of the safety of D4 for human health and the environment.
Under TSCA, EPA must complete the risk evaluation “as soon as practicable,” but no more than three and a half years after initiating the evaluation. The industry expects the D4 risk evaluation to be completed in the 2023-24 timeframe.