California cracks down on carcinogenic 1,4-dioxane in shampoo and detergent

California’s Department of Toxic Substances Control (DTSC) has proposed an amendment to the state’s Safer Consumer Products (SCP) regulations to add shampoos and manual detergents containing 1,4-dioxane at concentrations above 1 ppm to the US state’s list of Priority Products.

The DTSC states that topical exposure to 1,4-dioxane has carcinogenic and toxic effects on vital organs such as the liver, kidney, respiratory system, and nervous system. The ingredient is also highly water-soluble, creating grounds for hazardous contamination in both the water supply and the soil through dispersion.

Standard wastewater and drinking water treatments do not remove 1,4-dioxane. The increased use of recycled water for drinking water production has also exacerbated concerns about 1,4-dioxane in treated wastewater. Furthermore, workers who routinely use cleaning products have greater exposure to the chemical, posing increased health risks than the general population.

The DTSC has determined that, based on the SCP regulation criteria, 1,4-dioxane poses significant health risks for Californians, especially those living in vulnerable communities, workers, and children. 

At this time, the DTSC has not finalized actions regarding the regulation of 1,4-dioxane at levels greater than 1 ppm in shampoos and manual dish detergents. If the regulations are set, manufacturers are the first to be held responsible for compliance. If a manufacturer fails to comply, the responsibility may then transfer further down the supply chain to importers, assemblers, or retailers, following official notification from the DTSC.

Under Proposition 65, as overseen by the California Office of Environmental Health Hazard Assessment, businesses will have 12 months to comply with the necessary measures in disclosing the risks associated with an ingredient categorized as hazardous before they are liable and may receive a lawsuit or civil penalties of up to US$2,500 per violation per day.

Spearheading California

Exposure to 1,4-dioxane in consumer products poses significant risks to vital organs, including the liver and kidneys

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The California DTSC outlined a 2024–2026 SCP work plan that primarily aims to reduce hazardous chemical ingredients in consumer products by identifying alternatives to those ingredients or removing the products from consumer markets.

The 2024–2026 list identifies several priorities and considerations: environmental justice, the health of children and workers, potential releases of airborne contaminants, reductions in environmental microplastic releases, reductions in water supply contamination, and leveraging existing policy bodies for implementation.

In a previous case, California sought to ban anti-aging skin care products for minors amid the rising “Sephora kids” trend. The legislation was introduced in response to the promotion of such products to Gen Alpha consumers, despite the potential short- and long-term health risks posed by premature use of harsh anti-aging chemicals on young skin.

California was also the first US state to ban the use of plastic microbeads and glitter in leave-on cosmetics. The ban followed the EU’s lead and, in being the first US state to take action against these microplastic components in cosmetics. California’s state Assemblymember Tasha Boerner previously told Personal Care Insights that she hopes the legislation inspires other US states to “follow suit.” The bans, which take effect in 2029 and 2030, respectively, call for the use of safe, clean products and aim to address the “public health crisis” caused by microplastic-driven environmental pollution.