SALT LAKE CITY (AP) — A Utah company that sold devices to remove emission controls on vehicles has agreed to pay $500,000 to settle claims by the Environmental Protection Agency that it violated the Clean Air Act.

The EPA says the illegal devices allow cars to spew smoke containing particulates linked with health problems, including respiratory disease and bronchitis.

Ogden-based Edge Products LLC sold more than of the 9,000 devices until 2011.

The settlement announced Thursday also requires Edge Products to buy back the devices and spend more than $150,000 on a project to offset air pollution.

Edge Products says in a statement the devices were used exclusively for legal racing competitions but were abused by users of the devices. The company says they cooperated with the EPA to resolve the claims quickly.