A San Fernando Valley nail polish maker that is a major supplier to salons across the country said that it had removed the chemical toluene from its products.
The Campaign for Safe Cosmetics had asked OPI Products Inc. to remove toluene, formaldehyde and dibutyl phthalate, or DBP, from its products.
In a letter to an activist group, OPI also said it had stopped using DBP and was looking for alternatives to formaldehyde.
A founding member of the campaign, Women's Voices for the Earth of Missoula, Mont., on Thursday released news of OPI's formula change. That group, along with a California state senator who has worked to regulate chemicals in cosmetics, hailed OPI's move as an important step in worker safety.
OPI, based in North Hollywood, is privately held and does not release its sales and earnings. A company spokesman said OPI was the nation's largest professional nail-care company.
Consumers who use nail products at home or in salons are exposed to the chemicals, but manicurists and others who work in nail salons are at the greatest risk from prolonged exposure, activists said.
"It's meaningful that OPI has done this, but there's more to do," said Tracy Fairchild, spokeswoman for State Sen. Carole Migden, the San Francisco Democrat who sponsored California's Safe Cosmetics Act. "Making a huge investment in changing its product line sends a message to the industry that the status quo is changing."
The law, which went into effect in January, requires cosmetic companies to reveal ingredients that have been identified as causing cancer or reproductive harm.
Activists said that measure probably helped propel OPI's action.
OPI declined to comment but pointed to a document released by the Nail Manufacturers Council, an industry group, stating that exposure to the chemicals in nail salons is "very low."
In a letter to the Montana group, OPI Chief Operating Officer Eric Schwartz said the company had stopped using toluene, a solvent used to make polishes flow, in January. Toluene is listed by California under Proposition 65 as a chemical known to cause cancer or reproductive toxicity.
The firm added that it had stopped using DBP, a plasticizer used to make nail-care products more flexible, last spring.
Schwartz also wrote that the company's polishes did not contain formaldehyde, although some of the company's nail hardeners used the chemical as a strengthener.
"We continue to search for efficacious alternatives to formaldehyde in hardeners," Schwartz wrote.
A spokeswoman for L'Oreal USA, a subsidiary of the world's largest cosmetics company, said the company had discontinued use of all three chemicals several years ago.
Women's Voices for the Earth released news of OPI's change along with the report "Glossed Over: Health Hazards Associated with Toxic Exposure in Nail Salons."