Sodium lauryl sulfate – and cancer?

There is no evidence that SLS causes cancer. It’s simply a myth, not worth a second thought.

The International Agency on Cancer Research (IARC) does not classify SLS as a known, probable or possible human carcinogen. Nor does the US National Toxicology Program, California’s Proposition 65 list of carcinogens, the US Environmental Protection Agency, the European Union…

It’s a slam dunk on this one. 

The only thing SLS is known to do is irritate the skin. Especially at higher concentrations or when in contact with the skin for longer periods.

To help protect you from skin irritation, some uses of SLS are regulated in Australia via the Poisons Standard.¹

For example, manufacturers of rinse-off products containing 5–30% SLS have two choices. The product can display the warning ‘IF IN EYES WASH OUT IMMEDIATELY WITH WATER’. Otherwise, SLS is classified as a schedule 6 poison (a substance with moderate potential for causing harm), which means it must state ‘POISON’ on the container and meet certain packaging requirements.

A few other product categories must also follow the requirements for Schedule 6 poisons: rinse-off products containing more than 30% SLS, leave on products containing more than 1.5% SLS and toothpaste and oral hygiene products containing more than 5% SLS.

At levels below these, no specific warnings or precautions are deemed necessary.

Regulators around the world stand behind the safety of SLS.  

Australia’s industrial chemicals regulator, NICNAS (now AICIS), assessed the safety of SLS in 2013. This covered not only the alleged carcinogenicity of SLS, but also other potential adverse health effects.² Its conclusion? ‘The current controls are considered adequate to minimise the risk to public health posed by the known uses of this chemical in cosmetic or domestic products’.

The 1997 OECD (Organisation for Economic Co-operation and Development) report came to a similar conclusion that ‘the human health hazard assessment for SLS shows that at present the substance is of no concern for the general public’.³ 

The US Cosmetic Ingredient Review (CIR) Expert Panel found SLS to be safe for use in cosmetic and personal care products in 1983, 2002 and 2010.⁴

The Canadian Health Department states that ‘there is no evidence to show that SLS causes an undue safety risk to consumers when used as directed in cosmetics’.⁵ 

Yep, a slam dunk.

'The perception that SLS is a threat to human health is not scientifically supported, and claims made to the contrary should be regarded as false and misleading'.⁶