After pressure from an environmental group, a 78,000-signature petition and a court suit, Proctor & Gamble, which makes Tide and Tide Free & Gentle detergents, has agreed in a California court to significantly reduce the levels of the chemical 1,4 dioxane in its laundry products.

The substance is classified as a carcinogen under California's "Proposition 65," an initiative that requires the state to maintain a list of chemicals that cause cancer or birth defects. 1,4 dioxane was listed in 1988.

Women's Voices for the Earth, a women's environmental health advocacy group and one of the groups demanding that P&G remove the chemical, called the agreement a public health victory.

"We're glad that P&G is finally taking responsibility for this toxic contamination in their products," said WVE director of science and research, Alexandra Scranton. "It's obvious that it is possible for companies to manufacture products without 1,4 dioxane. We believe all companies should do the same to protect public health."

In a 2011 report, "Dirty Secrets: What's Hiding in your Cleaning Products?" the environmental group said independent testing had found the substance in the two Tide products.

Later, As You Sow, an Oakland-based nonprofit that promotes corporate responsibility through shareholder advocacy, filed a lawsuit, contending that P&G was required to put a warning label on the detergents.

Meanwhile, Lori Alper, a Boston mother of three who writes the blog, Groovy Green Livin, started a petition on, asking P&G to take the substance from its detergents. About 78,000 people signed it.

What especially irked the groups is that Tide Free & Gentle is marketed to mothers as a healthier choice for their children. The product website shows a cute infant and promotes the detergent as "as great clean that's gentle on your skin."

WVA said the levels of the substance were "high," while &G said in a statement earlier today that the amounts were "trace." A company infographic contends that a person could do laundry 24 hours a day, every day, for a lifetime and still be below safe limits for the chemical.

Still, "we knew women would be outraged" when the learned that a carcinogen was in their detergent, said Cassidy Randall, campaign and outreach manager for Women's Voices for the Earth who led the organization's campaign.

Earlier this week, a California judge signed the agreement.

P&G spokeswoman Suzette Middleton said the company was "pleased that we have been able to come to an agreement."

Middleton said that while the chemical existed as a result of manufacturing processes, and that the products were safe, "we continually work towards further reductions. We are pleased to report that we have been able to make significant reductions, without affecting the cleaning performance of our detergents."

P&G is to complete the reformulation process by September of 2013.

WVE said that it's unlikely old versions of the product will remain on the shelves for long after September. And because companies find it costly and problematic to manufacture different versions of the same product, it's like that P&G will distribute the new reformulation nationwide.