California Proposes Adding Microplastics to the Candidate Chemicals List

The California’s Department of Toxic Substances Control (DTSC) initiated rulemaking on June 20, 2025, to add microplastics to the Candidate Chemicals List. This list is required under the state’s Green Chemistry Initiative, or the Safer Consumer Products (SCP) Program, which was implemented to identify and regulate products that may expose consumers to “chemical of concern.” The law requires DTSC to publish a list of Candidate Chemicals. for the next step is for DTSC to develop a list of Priority Products (consumer products that contain one or more of the Candidate Chemicals). Once adopted, Priority Products may be subject to regulation. (For more information on the SCP Program, see the Packaginglaw.com article, Updates to California’s Safer Consumer Products Program and Food Packaging.)

In its Initial Statement of Reasons for adding microplastics to the Candidate Chemicals List, DTSC concluded that they should be listed due to their particle size and because they are environmental persistence and exhibit mobility in environmental media. In the proposed regulatory text, DTSC defines the term “microplastics” as “plastics that are less than 5 millimeters (mm) in their longest dimension, inclusive of those materials that are intentionally manufactured at those dimensions or are generated by the fragmentation of larger plastics.”