Methylisothiazolinone

Safety-in-use of methylisothiazolinone in cosmetic products June 2015

Methylisothiazolinone can no longer be considered safe at current levels according to a European Commission consumer safety committee.

The European Commission’s SCCS has published its opinion on the safety-in-use of MI in cosmetic products.

MI (CAS 2682-20-4) is a powerful biocide and preservative which has been used in cosmetics and personal care products. SCCS has looked at the safety-in-use of MI previously, but now has a significantly higher volume of toxicological data to produce a more definitive opinion.

MI was listed in Annex V/57 of Regulation (EC) No 1223/2009 to be used as preservative at maximum concentration of 0.01 % (100 ppm) in cosmetics products.

These new data have led the Committee to conclude that it can no longer be considered safe at concentrations up to 100 ppm in cosmetic rinse-off products, but a maximum concentration of 15 ppm is considered safe in these products. The Committee also concluded that these data do not support the safe use of MI as a preservative in leave-on hair cosmetic products up to a concentration limit of 100 ppm.

The Regulations may be amended in the future, and laboratories will need to be able to measure MI at lower levels than is now necessary.