California on Monday launched a lawsuit against 20 companies, accusing them of knowingly exposing children to lead in toys they manufactured or sold.
California Attorney General Jerry Brown said the firms, included Mattel Inc and Toys "R" Us, exposed children to potentially dangerous lead levels.
It follows a series of nationwide toy recalls this year which have seen tens of millions of largely Chinese-made products, including Barbie doll accessories, toy cars, trains and infant toys withdrawn from stores.
"Companies must take every reasonable step to assure that the products they handle are safe for children and their families and fully comply with the laws of California," Brown said. "Despite the lengthening global supply chain, every company that does business in this state must follow the law and protect consumers from lead and other toxic materials."
Los Angeles City Attorney Rocky Delgadillo said the suit filed in Alameda Superior Court was aimed at forcing toy companies to ensure there was no repeat of the violation by adopting procedures that ensured products were safe.
"Lead in toys poses a significant threat to the health and well being of our children," Delgadillo said. "This lawsuit is intended to ensure that these companies eliminate lead and other harmful substances from children's toys, once and for all."
Each violation of the California law known as Proposition 65 is punishable by a fine of up to US$2,500, in theory leaving the firms named in the suit facing a multimillion-dollar damages claim.
The companies named in the lawsuit include: Mattel, Fisher-Price, Michaels Stores, Toys "R" Us, Wal-Mart, Target, Sears, KB Toys, Costco Wholesale, A&A Global Industries, RC2, Eveready Battery Co, Kids II, Kmart, Marvel Entertainment as well as Toy Investments.
A spokeswoman for Mattel welcomed the lawsuit and said the toy giant had cooperated with authorities continuously.
"Mattel expected this development and believes that the attorney general's assumption of this case will be beneficial to all parties," a spokeswoman said in a statement quoted by the Los Angeles Times.
"The company has been in continuous communication with the California attorney general's office since the initiation of the recalls this summer and has cooperated fully," she said.
Brown told the Times he expected the companies to settle the suit by agreeing to "conditions such as testing or putting independent monitors in foreign countries."
Tougher procedures are necessary to protect consumers from "the new world order where the global supply chain goes from Beverly Hills to the hinterlands of China" and where some companies had "closed their eyes" to the threat of contamination, he said.