The California Department of Toxic Substances Control (DTSC) proposes adding shampoos containing 1,4-dioxane in concentrations greater than 1 ppm to the Priority Products List.

The measure will apply to any hair care product that is used for cleaning the hair and scalp, defined as:
• Products applied to wet hair, massaged into the hair, then rinsed out
• Products with multiple uses that indicate shampoo as one of the intended uses.
It will not apply to:
• Products that are left on the hair or scalp without rinsing them off
• Conditioners
• Products that are not intended for human use

The DTSC explains that with the classification of these shampoos as priority products, it will require manufacturers selling these products in California to assess whether 1,4-dioxane in concentrations above 1 ppm is necessary in the formulation, or whether there are functionally safer alternatives that would reduce exposure to 1,4-dioxane during the manufacture, use, or disposal of these products.
The Californian authority believes that reducing 1,4-dioxane in consumer products and the environment would improve the safety of homes and workplaces, make the environment more sustainable and clean up drinking water. It could also reduce health effects, such as …