After facing recall after recall of millions of Chinese-made items, the nation’s biggest toy sellers are imposing stricter measures on their suppliers – including tougher standards for lead content – to get ahead of expected new federal legislation.

Wal-Mart Stores Inc. and Toys “R” Us Inc., the nation’s top two toy sellers, are setting a much tighter standard for the amount of lead allowed on surface paint for toys shipped to their chains on or after March 1. The companies are also phasing out chemicals found in PVC, or vinyl, that have raised safety concerns in products for infants and young children.

Target Corp., the nation’s No. 2 discounter, said it was working with its “vendors, industry leaders and the Consumer Product Safety Commission,” but did not give specifics.