Green Groups Sue EPA Over Two Chip-Making Chemicals Approved Without Full Risk Data
CHIPS Communities United and the Sierra Club filed suit on Friday against the US Environmental Protection Agency, arguing the agency cleared two new substances for semiconductor manufacturing even though it admits it never measured how dangerous they really are. Earthjustice, the environmental law firm, brought the petitions for review in the Ninth Circuit Court of Appeals in San Francisco, according to a complaint that names the EPA as respondent.
The two chemicals are photoacid generators, or PAGs, used in the lithography steps that etch circuit patterns onto silicon wafers, Bloomberg Law confirmed in its own report on the filings. The EPA approved them for immediate commercial use after flagging potential hazards that include cancer, neurological damage, and even sudden death, the groups say. Yet the agency also acknowledged it lacked the information needed to calculate the full extent of those risks.
The identities of the substances are redacted in the court documents, where they appear under their EPA premanufacture notice numbers, P-26-0029 and P-26-0045, because the agency has treated their chemical names as confidential business information.
Jonathan Kalmuss-Katz, senior attorney at Earthjustice, said the approvals amount to a dangerous shortcut. "The Trump administration is rushing dangerous chemicals to market without the review or the protection that the law requires," he said. "Here, EPA admits that it has not evaluated the full extent of these chemicals' health risks, yet it is still sending them into communities across the country and leaving the public to discover their effects one doctor's visit at a time."
What the Lawsuit Alleges Under TSCA
The legal argument rests on the Toxic Substances Control Act, the main federal statute governing industrial chemicals. The groups contend the EPA skipped the full risk-assessment steps TSCA requires before a new chemical enters commerce. Under the law, the agency must weigh a substance's hazards against the exposures workers and nearby residents could face, and it can impose conditions such as protective equipment requirements or use limits if data is thin.
Here, the complainants argue, the EPA neither completed that analysis nor attached the safeguards that a partial analysis would demand. Instead it let the PAGs ship while conceding that the numbers needed to judge their dangers simply were not in hand.
Judith Barish, coalition director of CHIPS Communities United, a national alliance of unions, environmental advocates, and community groups living near chip plants, pointed to decades of complaints from fab towns. "Neighbors and workers are exposed to toxic chemicals in semiconductor factories," she said. "Over decades, workers in chip factories have been harmed by workplace exposure and residents of nearby communities have been impacted by hazardous air or water that is contaminated by these chemicals." The coalition wants the EPA to stop clearing substances whose risks it does not understand.
Jane Williams, chair of the Sierra Club's Grassroots Network National Clean Air Team, widened the lens to the AI boom that is pulling chip production into new regions. "The rush to build more and more data centers is causing harm far beyond the data centers themselves," she said. "From the plants where toxic chemicals are used to make semiconductors, to the roads these chemicals are transported on, and finally to the incinerators where they are disposed, EPA's approval of these dangerously unstudied chemicals places the public at risk." She described the two PAGs as suspected persistent, bioaccumulative toxins, a class of compounds that can show up in breast milk and cord blood.
Why Photoacid Generators Matter to Chipmaking
PAGs sit at the heart of chemically amplified photoresists, the light-sensitive coatings that define circuit patterns on wafers. When a resist absorbs light in a lithography exposure, the PAG decomposes to release acid, and that acid then catalyses the solubility switch that turns the latent image into a usable mask for etching. Without PAGs, modern patterning at the tiny pitches used in leading-edge logic and memory would not be possible.
The fluorine chemistry that makes PAGs effective is also the chemistry that worries regulators. Fluorinated groups control acid diffusion, improve film uniformity, and lower surface energy across the coated wafer, which is why PAGs have leaned on per- and polyfluoroalkyl substances, or PFAS. Those same "forever chemicals" resist breakdown in the environment, and they have become a focus of state and federal scrutiny well beyond the fab floor.
Imec, the Belgian research institute that coordinates much of Europe's semiconductor R&D, has been working with suppliers since 2023 on PFAS-free lithography materials. Its scientists reported at the 2025 SPIE Advanced Litho + Patterning conference that PFAS-free resists can hold their own on dense 32nm line-space patterns and 36nm hexagonal contact holes, though they also found that removing fluorine shrinks the design space for pushing resolution further. Europe's chip research community has been pushing for years on the same problem the US groups now take to court: how to keep advanced patterning performant without the persistent chemistry underneath.
The tension is not new. Semiconductor manufacturing has long been a major source of PFAS alongside other industrial users, and the chemistries appear not only in resists but in rinses, antireflective coatings, and immersion-top coatings used at multiple stages of wafer processing. Suppliers treat their exact formulations as proprietary, which makes independent risk assessment harder — and which is precisely the opacity the new lawsuit challenges.
Data Centers and the Expanding Footprint of Chip Chemicals
The lawsuit arrives as US chip capacity expands on multiple fronts, with new fabs rising in Arizona, Ohio, New York, and Texas under the CHIPS Act build-out and hyperscale data center construction running at record pace. Each new facility brings a fresh set of workers and neighbors into contact with the chemicals semiconductor processing depends on.
Earthjustice pointed to the broader chemical load that already surrounds digital infrastructure, including refrigerants, Teflon-type coatings used in cable insulation, fluorinated lubricants, and sealing compounds. The Natural Resources Defense Council has separately warned that data center cooling systems can consume and pollute large volumes of water, with some immersion cooling approaches relying on PFAS-based fluids.
The groups do not stop at the factory gate. Their petitions note that the chemicals travel from production plants to incineration and disposal sites, spreading potential exposure along transport corridors and into communities that never signed up to host chip supply chains. "This action is an assault on the future," Williams said.
What Happens Next
The petitions now move through the Ninth Circuit, where the court will decide whether the EPA's approvals can stand and whether the agency must go back and do the risk work it skipped. A ruling against the EPA could force a re-review of the two PAGs and set a precedent for how the agency handles confidential, fast-tracked chemical submissions from the chip industry.
The case also lands in a broader political fight. Earthjustice noted that the EPA last year proposed changes to how it conducts risk evaluations for chemicals already on the market, changes the group said would let the agency ignore real-world exposures. The plaintiffs framed Friday's filing as a direct challenge to that direction: approve nothing whose risks cannot be documented.
For chipmakers and their material suppliers, the stakes are practical as well as legal. Lithography chemicals are engineered to hit exacting performance targets, and a forced substitution is not a matter of swapping one bottle for another. Any regulatory brake on PAG chemistry lands on a supply chain that is already stretched by AI demand, and it would accelerate the industry's search for PFAS-free alternatives that imec and others say are close but not yet equivalent at the most aggressive nodes.
The courts will now decide how fast that transition happens, and under whose rules. For the communities that live near fabs, the lawsuit is a bid to get the same answer the industry keeps giving to its customers: show the data before you ship the product.
Sources: Earthjustice, Common Dreams, Bloomberg Law, imec. More chip-industry coverage: Semiconductors.