Millions of toys made in China have been recalled over the last three months due to unsafe levels of lead paint, which is toxic and can pose serious health risks, including brain damage, in children.

The Center for Environmental Health also said it found high lead levels in vinyl lunch boxes and backpacks made by Sassafras Enterprises of Chicago.

The group filed a legal notice accusing privately-owned Sassafras of violating a 1986 California law that prohibits exposing consumers to carcinogens without warning.

A spokeswoman for Sassafras said the company tests its products for lead and that she was unaware of the group's statement.

The advocacy group also notified 10 retail store chains that they were selling toys with excessive lead in violation of the California law.

The stores were Toys "R" Us, Wal-Mart Stores Inc, Kmart, Sears, KB Toys, Target, RC2 Corp, Michael's Stores Inc, Costco Wholesale Corp and Kids II Inc.

Michael Green, executive director of the center, said the legal notices were the first step in potential lawsuits against the companies.

"We want companies to test for lead before selling these items," Green said. "The federal government isn't doing its job."

Democrats in the US Senate and House this month introduced legislation that would virtually ban lead from toys and other goods used by children younger than six. Lawmakers have criticized the US Consumer Product Safety Commission for not doing enough to protect children from excessive lead.

The Center for Environmental Health took similar action when it found unsafe levels of lead in vinyl bibs at Wal-Mart and Toys "R" Us stores in California, which resulted in both retailers pulling all vinyl bibs from their shelves nationwide, Green said.