Two federal agencies are investigating The Home Depot after receiving reports that its contractors did not comply with lead paint regulations.

WSB-TV, a television station in Atlanta where Home Depot is headquartered, said that it spent months investigating claims of “questionable business practices” and uncovered a number of customer complaints about contract work involving the removal of lead paint.

In one instance, Home Depot was hired to replace windows in an older home in Augusta, Maine, and charged extra for the work after tests showed the presence of lead paint. But workers allegedly took no special precautions and used no special equipment. In that case, the company settled with the homeowner, and the Occupational Safety and Health Administration fined both Home Depot and the contractor who did the work, the station said.

Lead paint was common until 1978, when the federal government banned its use in homes. Later, the EPA issued the Renovation, Repair and Painting Rule, which includes a number of requirements for contractors aimed at protecting people, especially children, from lead.

Home Depot said in a filing in March that it was aware the EPA was looking into its compliance with lead-paint rules, MarketWatch reported. A Home Depot representative told the Atlanta TV station that lead-paint work makes up only a very small fraction of its total business and that it was cooperating with the investigation.

The retailer isn’t the first home improvement business to run afoul of the federal lead-paint rule. In a similar case, Sears settled with the EPA and the Department of Justice in 2016 by agreeing to pay $400,000 for violating the rules.