Overview
The EPA is the United States federal agency for environmental protection. It writes and enforces a large share of US environmental law, covering air, water, waste and chemicals, and it carries out the technical work behind those rules.
Chemicals are one of its main jobs. The agency runs the Toxic Substances Control Act, the federal law that lets it review the chemicals already on the US market, judge whether their uses pose an unreasonable risk, and then restrict or ban them where needed.
Why it matters for products
If you place products on the US market, the EPA's chemical decisions shape what you can use. A TSCA risk evaluation can lead to limits on substances such as certain solvents and flame retardants, much as the EU does through its own restrictions. State rules sit alongside the federal layer, so a product may also have to meet requirements like California's Proposition 65 warnings, which the EPA does not run but which cover similar ground.
Note: general educational information, not legal advice. Check the official source before relying on it.