California could force some manufacturers to change their formulas for dishwashing liquids, laundry detergents, and face scrubs if they contain certain levels of a probable carcinogen, 1,4-dioxane.

A component of that chemical helps get clothes clean in cold water and provides the bubbles consumers expect from their bathroom soap.

The state Department of Toxic Substances Control is considering adding the man-made solvent to the list of chemicals regulated under its Safer Consumer Products regulations. If the state takes that step, manufacturers would have to research safer chemical alternatives when concentrations of 1,4-dioxane exceed a set threshold.

During a public meeting Aug. 21 in Sacramento, manufacturers and industry groups said the chemical—a byproduct of normal manufacturing processes—is difficult to remove and measure in finished products.

“The goal is always to get to the lowest level possible,” said Kathleen Stanton, a senior director with American Cleaning Institute, an industry group that represents 140 companies like Dow Chemical Co., DuPont Nutrition & Biosciences, L’Oreal USA, and Unilever.

“It is not an intentionally-added ingredient nor is it added as a raw material,” she said.

Unregulated

The federal government doesn’t regulate 1,4-dioxane in products or drinking water.

The extent of its presence in products is hard to quantify because it is considered a byproduct, not an ingredient added on purpose, so it isn’t listed on product labels. DTSC is doing its own product testing to get a sense of how much of the chemical is in common household products.

“It can be pretty tough to know what products it is in,” said Anne-Cooper Doherty, a senior environmental scientist with the state agency.

A survey of water suppliers in California found 1,4-dioxane in areas in Los Angeles, Orange, Santa Barbara, and others serving nearly half of the state’s population.

It’s hard to extract from water supplies and conventional waste water treatment plants don’t remove it either. With the state increasing its reliance on recycled water, the issue could become more serious, Doherty said.

“It’s more about the combined use exposure and drinking water consumers that we’re concerned about,” she said.

Potential Threshold

If the state does establish a threshold, it would take effect no earlier than 2022. One part per million has been discussed but is not final.

In New York, legislation awaiting the governor’s signature would require 1,4-dioxane levels below 1 parts per million in personal care and cleaning products, and 10 parts per million in cosmetics, by the end of 2023.

Last year, the Citizens Campaign for the Environment, which operates in New York and Connecticut, tested consumer products and issued a report on the lab results. A body wash from Victoria’s Secret had the highest concentration of the chemical, at 17 parts per million, Executive Director Adrienne Esposito said.

Canberra Corp., a Toledo, Ohio-based manufacturer of green cleaning chemicals, said replacing 1,4-dioxane would be technically difficult and costly but the company is focused on green chemistry and sustainability, said Roger McFadden, its vice president of sustainability and innovation.

“I don’t think anyone wants to have 1,4-dioxane in its products,” he said. “But there’s the practicability of that that we need to address as well.”

The supply chain can also be a problem, according to Seventh Generation Sustainability & Authenticity Director Martin Wolf. Many companies buy surfactants, which contain 1,4-dioxane, from outside manufacturers to use in their products.

When Seventh Generation sought to lower concentrations of the chemical in its products, the Vermont company found cross-contamination from outside facilities that complicated efforts, Wolf said.