08/29/2025

California’s Plan to List Microplastics as Candidate Chemical Draws Concern From Key Sectors

Chemical Watch | Bobby DeMuro | August 28, 2025

California’s Plan to List Microplastics as Candidate Chemical Draws Concern From Key Sectors

Chemical Watch | Bobby DeMuro | August 28, 2025

Industry groups have warned that California’s proposal to add microplastics to its Safer Consumer Products (SCP) candidate chemicals list could lead to unintended downstream consequences for transportation, fire safety, textiles and other critical areas.

The California Department of Toxic Substances Control (DTSC) floated the microplastics listing in June. If finalised, it could open the door for DTSC to designate goods containing microplastics as priority products, a move that would require manufacturers to complete an alternatives analysis (AA) or redesign designated products.

Supporters of the listing called it a necessary first step to address pervasive plastic contamination. But opponents said it was a "significant overreach" to treat heterogeneous microplastics as a single substance, and ultimately incompatible with the state’s chemical-centric scheme.

Meanwhile, downstream business groups submitted comments describing how the proposed listing could have unintended impacts on a broad array of sectors, highlighting the challenges inherent in trying to address something as pervasive as microplastics.

Industry-specific concerns

Groups representing sectors ranging from tyres to building materials and appliances said the SCP programme was designed to address chemicals that are intentionally added to products. The release of microplastics, by contrast, often occurs during product degradation or disposal – conditions not readily addressed by the ingredient removal or reformulation tools available under the SCP scheme.

If the listing proceeds as proposed, these sectors could be left without viable alternatives, potentially jeopardising safety, performance or affordability, they said.

For example, the US Tire Manufacturers Association (USTMA) said that treating tyre and road wear particles (TRWP) as microplastics could risk trade-offs to automotive safety.

TRWP "cannot be eliminated from tyre usage" because they are formed from the friction needed for grip and braking and include both tread rubber and pavement, the USTMA said.

The Alliance for Automotive Innovation (AAI) warned of "adverse impacts across formulations" should tyre makers be compelled to conduct an AA or reformulate their products – a process the group said may not be economically feasible.

Building materials suppliers similarly flagged public safety risks.

The Gypsum Association (GA), which represents gypsum building panel manufacturers, warned that broad restrictions on materials containing microplastics could undermine fire-resistant products critical in wildfire-prone regions.

"Overly restrictive regulation of microplastics, without differentiation between persistent, harmful particles and essential, encapsulated materials, may compromise the fire safety of buildings and the public," the GA said.

The group pressed the DTSC to set measurement methods and thresholds and map a phase-out timeline so companies can reformulate if regulators move forward with any plans to regulate microplastics.

Appliance makers, meanwhile, raised possible implications for household appliances like clothes washers if future regulations seek to control the release of microplastics, including microfibre pollution from synthetic textiles, through filtration requirements.

The Association of Home Appliance Manufacturers (AHAM) said that efforts to capture microfibre pollution this way "begin from the false premise that mandatory filters will meaningfully diminish the presence of microfibres in the environment".

"Clothes washers are designed to wash clothes, not filter water," the AHAM said, citing a study that found some washer filters nearly doubled energy and water use, potentially driving more microfibre shedding through longer cycles.

The group urged the DTSC to focus on textile design and consensus performance standards instead of pollution control.

Environmental groups respond

Nevertheless, environmental advocates interviewed by Chemical Watch News & Insight said that a broad listing is the necessary starting point to manage a diffuse, cross-sector problem.

Joanne Brasch, director of advocacy at the California Product Stewardship Council (CPSC), said the SCP programme’s structure is meant to address chemicals encountered across broad sectors of society, regardless of how difficult remediation may be.

"Yes, some products will be more difficult to prevent microplastic emissions, but that shouldn’t stop us from measuring and managing," Brasch said. "It’s still less difficult and costly than remediation."

The Natural Resources Defense Council (NRDC) said the DTSC should not let feasibility debates overshadow core questions about the hazards of microplastics.

Avi Kar, NRDC’s senior director for toxics and environmental health, said that regulators "should separate out the question of whether chemicals pose health concerns from how we manage them".

"Harmful chemicals are harmful by definition; they don’t become less harmful because there is an ‘important’ use," he said. "We should not be assessing what is harmful based on how that might affect uses. That’s backwards and distorts the inquiry."