Salicylic acid is a synthetic ingredient commonly used in cosmetics, that usually comes in the form of a white, fluffy, crystalline powder. We use this ingredient as an antibacterial agent in our antibacterial hand wash.

Salicylic acid is typically produced by reacting sodium phenoxide with carbon dioxide, and is the key ingredient used to create aspirin (acetylsalicylic acid). Salicylic acid is naturally synthesized in some plants - particularly in the leaves and bark of the willow (Salix alba) and meadowsweet (Filipendula ulmaria), where it plays an important role in the plant defence response. This ingredient has analgesic, anti-inflammatory and antibacterial properties, and willow bark (which contains high salicylic acid content) has a long history of use in traditional medicines for pain relief. Salicylic acid has been shown to have significant antibacterial activity, and is used in many skin care products and in some treatments for acne and psoriasis.

Regarding its safety profile, salicylic acid, along with a group of salicylates, were assessed by the Cosmetic Ingredient Review (CIR) Expert Panel in 2003, and reassessed in 2019. They reviewed their safety for dermal exposure in cosmetics and concluded they are “safe in cosmetics in the present practices of use and concentration described in the safety assessment, when formulated to be non-irritating and non-sensitizing”. Salicylic acid is also listed by the European Chemical Agency (ECHA) as being readily biodegradable, with low potential for bioaccumulation or aquatic toxicity.

Other names: C₇H₆O₃, Acidum Salicylicum, 2-Hydroxybenzoic Acid, Phenol-2-Carboxylic Acid

Chemical class: Carboxylic Acids, Phenols

REFERENCES

Jing Bo Jin, Bin Cai, Jian-Min Zhou. (2017). Metabolism and Signaling in Plants. Hormone, Academic Press. 8: 273-289. ISBN 9780128115626. https://doi.org/10.1016/B978-0-12-811562-6.00008-6.

Adamczak, A., Ożarowski, M., & Karpiński, T. M. (2019). Antibacterial Activity of Some Flavonoids and Organic Acids Widely Distributed in Plants. Journal of clinical medicine, 9(1), 109. https://doi.org/10.3390/jcm9010109

Cosmetic Ingredient Review Expert Panel. (2019). Amended Safety Assessment of Salicylic Acid and Salicylates as Used in Cosmetics. https://www.cir-safety.org/sites/default/files/salicy042019FAR.pdf

European Chemicals Agency (2022). Salicylic acid. EC number: 200-712-3 | CAS number: 69-72-7. https://echa.europa.eu/registration-dossier/-/registered-dossier/14544/6/1
https://echa.europa.eu/web/guest/legal-notice

National Center for Biotechnology Information (2022). PubChem Compound Summary for CID 338, Salicylic acid. https://pubchem.ncbi.nlm.nih.gov/compound/Salicylic-acid

Temperate Plants Database, Ken Fern. temperate.theferns.info. 2022-03-07. temperate.theferns.info/viewtropical.php?id=Salix+alba