A Petaluma company that sold unregistered pesticides has agreed to pay $316,000 in civil penalties, the U.S. Environmental Protection Agency said Wednesday.

Hydrofarm Inc., one of the nation's largest wholesalers of agricultural and hydroponics supplies, also agreed to stop selling the two products, the agency said.

The company had been selling sulfur to control mildew in greenhouses and another product, Nutralife Plant Products H202, containing 29 percent hydrogen peroxide. It was used to sanitize hydroponics equipment.

The EPA said neither product came with adequate handling instructions to minimize the risks of exposure.

Nutralife Plant Products H202 contained hydrogen peroxide at concentrations that can cause irreversible eye damage and skin burns and can be fatal if inhaled, the agency said.

The products came to light through a tip from a separate hydroponics store that was being inspected by the state Department of Pesticide Regulation.

Selling unregistered pesticides is a violation of the federal law that ensures the safe distribution, handling and application of pesticides, the EPA said.

Hydrofarm president Peter Wardenburg said he stopped distributing the products as soon as he learned of the problem. They were sold for a few months in 2011, he said.

The company that made them said they were in compliance with all laws, he said.

"We now require all of our vendors to warranty their products for proper labeling and registration where applicable," Wardenburg said in an email.

The 35-year-old company is the oldest and largest wholesaler and manufacturer of hydroponics equipment and high-intensity grow lights in the United States, according to its website.

It has six distribution centers nationwide. Hydrofarm West is located on South McDowell Extension in Petaluma.