California DTSC Adds Microplastics to Candidate Chemicals List

Author: Nathan Jong

On June 18, 2026, the California Department of Toxic Substances Control (DTSC) officially added microplastics to the Candidate Chemicals List under its Safer Consumer Products (SCP) Program. DTSC defines microplastics as plastic particles smaller than 5 millimeters. These tiny plastic particles can come from a variety of everyday products including plastic packaging, synthetic fabrics, and coatings. Microplastics are either added intentionally to products or produced by plastic products that fragment into microplastics instead of fully degrading.

What Does This Mean?

The SCP Program is designed to identify chemicals that may pose risks to people or the environment and encourage manufacturers to look for safer alternatives. Some of the risks associated with these chemicals include carcinogenicity, reproductive and developmental toxicity, and environmental impacts, such as toxicity to fish, wildlife, and aquatic organisms. Adding a substance to the Candidate Chemicals List does not ban it. Instead, it allows DTSC to identify Priority Products that contain or generate the chemical, which may lead manufacturers to evaluate safer alternatives.

Why Is This Important?

Microplastics have become a growing environmental concern because they are widespread and slow to break down. Researchers have detected microplastics in:

• Air
• Drinking water
• Food
• Household dust
• Human blood and lung tissue
• Soil
• Waterways

Because microplastics can travel long distances and persist in the environment for a long time, there is growing concern among regulators about consumer products that contain or generate microplastics and their potential environmental impacts.

Industry Pushback

DTSC’s decision has received pushback from industry groups such as the American Chemistry Council, American Institute for Packaging and the Environment, Plastics Industry Association, Plastic Pipe and Fittings Association, and The Vinyl Institute. Industry has expressed concern about higher costs and additional compliance responsibilities because of the listing, as manufacturers will need to evaluate alternative materials, reformulate products, or modify manufacturing processes.

Industry Position

Industry groups argue that microplastics are too broad to be considered a single “chemical” under DTSC’s definition because they consist of many different materials rather than one specific substance. They also argue that many microplastics fall outside the scope of the SCP Program because they are not “consumer products” as defined in California Health & Safety Code § 25251(b), which covers products or components used, purchased, or leased by a person. While California Health & Safety Code § 19 defines a “person” broadly to include individuals as well as corporations and other business entities, industry groups point to Health & Safety Code § 5, which provides that definitions apply unless “the provision or the context otherwise requires.” Based on that language, they argue that “person” in the consumer product definition should be interpreted to mean an individual consumer. Under this interpretation, plastic resin pellets are raw materials purchased by manufacturers rather than products intended for consumer use. Additionally, secondary microplastics are generated through the breakdown of larger plastic items as byproducts rather than consumer products themselves.

DTSC’s Response

DTSC disagrees, stating that microplastics can be regulated as a chemical category despite consisting of different types of plastics. The agency notes that the SCP Program has previously regulated broad classes of substances, such as per- and polyfluoroalkyl substances (PFAS), and maintains that microplastics exhibit hazard traits sufficient to justify their inclusion on the Candidate Chemicals List.

What Could This Mean for Your Facility?

While no immediate requirements have been announced, this listing could be the first step toward additional product and reporting requirements in the future. Facilities that manufacture, use, or sell plastic-containing products should keep an eye on DTSC’s next actions, particularly any future Priority Product designations. Potential impacts could include:

• Increased reporting requirements under environmental permitting programs
• Consideration of microplastics in National Pollutant Discharge Elimination System (NPDES) permit applications
• Expanded supplier notification and product disclosure obligations
• Additional Safety Data Sheet (SDS) considerations
• Future state restrictions or bans on products that intentionally contain or generate microplastics

Final Thoughts

DTSC’s decision to add microplastics to the Candidate Chemicals List represents a step in California’s efforts to address emerging environmental contaminants. While the action does not create any immediate compliance obligations, it opens the door for DTSC to evaluate specific products that contain or generate microplastics and potentially regulate them through future Priority Product rulemakings.

At the same time, many scientific and regulatory questions remain. The United States Environmental Protection Agency (U.S. EPA) recently declined to include microplastics in its proposed Unregulated Contaminant Monitoring Rule 6, citing the lack of validated analytical methods for monitoring microplastics in drinking water and ongoing research needs. As a result, widespread environmental regulation of microplastics is likely still several years away while monitoring methods continue to be developed to better understand the potential human health and ecological impacts.

ALL4 will continue to track developments under California’s Safer Consumer Products Program and provide updates as additional information becomes available. Our staff have extensive experience evaluating applicability of state-specific environmental, health, and safety requirements and their impacts, and developing strategies to respond to new regulations. For questions about this topic or how it may affect your facility, contact Nathan Jong njong@all4inc.com or Cody Fridley cfridley@all4inc.com.