Salicylic acid has been used in cosmetics and dermatology for many years, more or less as soon as it was available in the 1840s. In fact it was used before that unknowingly as willow bark, from which it was first isolated, was already in use as a folk medicine before that. This use is referred to by Roman writers. But it has recently come under a bit of a cloud following its classification by the European Chemicals Agency as a Category 2 CMR.
This categorisation sounds a bit scary, as a CMR is a product that causes cancer, mutations or interferes with reproduction. Category indicates that although there is no direct evidence, there is a potential risk. So not surprisingly it is forbidden for products containing CMRs to be included in cosmetics without positive approval of them from the Scientific Committe on Consumer Safety. And in the case of salicylic acid this approval has indeed been granted.
The main details are that it continues to approved for use as a preservative in cosmetic products at a concentration of up to 0.5 % (Annex V, section 3).
It is still acceptable for uses other than as preservative at a concentration up to 3.0 % for the cosmetic rinse-off hair products and up to 2.0 % for other products (Annex III, section 98).
What it does mean is that products containing salicylic acid need to be notified as such when being notified on the CPNP portal and its UK equivalent. This is not particularly troublesome to do – you just fill in that bit when you come to it. It does mean however that your product will be on the list if salicylic acid is ever to be banned at any time in the future. I don’t think this is something to worry about unduly. Lots of products contain salicylic acid so you’ll have plenty of company in the event.
These restrictions won’t cramp the style of most formulators. Its main use is as an anti-dandruff agent in shampoos and as an active against spots. Both of these applications can easily be achieved within those concentration limits. There are a few more detailed restrictions – you can’t use it in products intended for children under the age of 3. Again, this isn’t something that most formulators would consider doing. It is also banned in oral products and ones that could get into the lungs – once again products for which there is no particular reason why it would be included.
The other products which use salicylic acid on the skin are wart paints. These fall under the pharmaceutical regulations and so their control is down to the medical licensing authorities.
So basically salicylic acid remains for practical purposes just as available to formulators as it ever has been. But the report that drew that conclusion is still worth having a look at if you have some time. For one thing the shear depth of the evaluation is impressive. A great deal of data was assessed, collated and reported in an easy to read format. (By the standards of scientific papers that is. It still not exactly a page-turner.) It also finds some suggestion that salicylic acid may be an endocrine disruptor. Endocrine disruption is a bit like the boy who cried wolf of toxicological issues. It was first suggested as a theoretical problem in the 1950s, and came to wide notice in Rachel Carson’s book Silent Spring. And it is certainly an effect that is real and can be demostrated in some animals. The issue of parabens is one of potential endocrine disruption.
But in over seventy years of people being aware of the problem, not one case has been demonstrated of any human suffering any issues as a result. This doesn’t mean it never will be – and the boy who cried wolf of course did eventually encounter a wolf. Maybe salicylic acid will turn out to be the first one – but it doesn’t seem very likely. We need to be vigilant and keep an open mind. But for now, we can carry on using salicylic acid.
Details of the regulations on salicylic acid can be found at L 307/16 EN Official Journal of the European Union 28.11.2019