When the U.S. Environmental Protection Agency announced on Nov. 24 that it was posting the “default values” it uses to evaluate new chemicals, the news barely made a ripple outside regulatory circles. But for companies that make, import or use novel substances, the move represents a significant shift that could affect project timelines, product development and risk management strategies.

Under Section 5 of the Toxic Substances Control Act (TSCA), the EPA must review every new chemical before it can be manufactured or sold in the United States to ensure it does not pose an unreasonable risk to people or the environment. Regulators estimate how much of the substance will be released into the environment, how workers might be exposed and what the potential health impacts could be. If a company doesn’t supply specific data on those points—because the chemical hasn’t been produced at scale yet—the EPA relies on standardized assumptions about things like residual material left in process equipment, the types of containers used to transport the chemical and the emissions that occur during cleaning and maintenance.

Those assumptions have long been something of a black box. Companies would submit data, wait for the EPA’s feedback and sometimes discover that regulators used more conservative estimates than expected, triggering requests for additional studies and delaying projects. By publishing its default values, the agency is putting its cards on the table. Firms can now see the baseline release and exposure assumptions the EPA uses and tailor their submissions accordingly. The guide draws on models from the agency’s Chemical Screening Tool for Exposures and Environmental Releases, generic scenario documents and international emission scenario documents. EPA officials say the transparency should speed up reviews and reduce the need for rework, freeing up agency resources to focus on substances that truly require closer scrutiny.

For business owners, the benefits go beyond shorter approval times. Having clear insight into EPA’s assumptions allows companies to better assess potential liabilities early in the product development process. If the default assumptions for a certain type of manufacturing process suggest higher worker exposure or environmental release than previously anticipated, a firm can redesign equipment, modify procedures or gather additional data before submitting its application. That proactive approach not only reduces regulatory friction but also lowers the likelihood of costly retrofits or cleanup obligations later.

The move also aligns with broader trends in environmental compliance. Regulators and investors are pushing for greater transparency and accountability around chemical use, and disclosures are increasingly expected across supply chains. By making its own methodologies public, the EPA is signaling that it expects industry to respond in kind. Business leaders should therefore consider the following steps:

• Review the default values and compare them to your processes. If your operations differ significantly from the assumptions, document those differences and be prepared to provide supporting data.
• Engage technical experts early. Environmental consultants and industrial hygienists can help evaluate whether your equipment, containers and emission controls meet or exceed the EPA’s default assumptions.
• Update insurance coverage. Even with clearer guidance, new chemicals carry uncertainties. Review pollution legal liability and workers’ compensation policies to ensure they reflect potential risks associated with novel substances.
• Participate in EPA’s call for data. The agency has invited industry to submit representative information to refine its assumptions. Contributing to this process could lead to more realistic default values that reflect your sector’s best practices.

Greater transparency is welcome, but it doesn’t absolve companies of responsibility. Meeting or exceeding the EPA’s assumptions is still the best way to avoid enforcement actions and litigation. With clear benchmarks now on the table, businesses have an opportunity to streamline compliance and strengthen environmental stewardship—both of which are essential to managing pollution liability in an evolving regulatory landscape.