New York state Governor Andrew Cuomo has signed into law a bill banning all but trace amounts of 1,4-dioxane in personal care and cleaning products, despite industry protests that it could cost more than $2bn to implement. The legislation (S 4389B/A 6295A), which cleared the legislature in June and was approved by Mr Cuomo on 9 December, is intended to address 1,4-dioxane contamination in drinking water by limiting the amount that can be present in consumer products.

The substance, a possible carcinogen and one of the first ten substances subject to TSCA evaluation, can appear as a contaminant during the manufacturing process of certain cosmetics, detergents and shampoos. It has been found in high concentrations in Long Island, New York, drinking water.

The law puts in place a phase-down schedule that will see permissible levels set at ten parts per million (10ppm) for cosmetics, all the way down to 1ppm for certain personal care and cleaning products, by the end of 2023. And beginning in 2025, the state’s department of environmental conservation will be charged with determining whether those trace concentration thresholds should be lowered to offer better protection to human health and the environment. Those not in compliance could face civil penalties of up to $1,000 for each day of a violation, increasing to $2,500 for a second offense. However, one-year compliance waivers may be given out when a manufacturer "has taken steps to reduce the presence of 1,4-dioxane in that product and is unable to comply with the requirements".

With 1,4-dioxane having an affinity to water, a fairly long half life, and an inability to bind to soil, it's probably a good thing to see it being phased out. Sure it will cost manufacturer significant money to remove the contamination from personal care products -- it's something that rides along with useful chemicals -- but the cost will be spread out over millions of consumers, and it's a pretty nasty chemical that probably is carcinogenic. Wastewater treatment plants and septic systems can eat away at the biological material and remove some of the chemicals that are solids, the truth is most things that get flushed down the toilet or sink, ultimately do end up again in our drinking water.