Methylisothiazolinone (MI), a preservative found in hundreds of cosmetic products, can cause rashes, lumps, blisters, itchy eyes and facial swelling, and according to the a report by BBC One show Watchdog, has an allergic reaction rate of 10 per cent, as opposed to a normal one or two per cent.
Experts say the scale of the allergic reactions has reached 'epidemic proportions', and have urged cosmetics companies to remove the ingredient - which has no use other than to extend the shelf life of an item - from their products.
Leading dermatologist Dr Ian White, from St Thomas' Hospital in London, told the Daily Mail: "The frequency of reactions to MI is unprecedented in my experience.
"We've never seen anything quite like it. Contact allergy to this permitted preservative is now of epidemic proportions. Immediate action needs to be taken by industry."
The Mail reports that cosmetic giant Johnson & Johnson is taking the chemical out of its PIz Buin sun cream brand, while Molton Brown is removing the ingredient from its products as of this month.
Watchdog airs on BBC One tonight at 8pm.
Have you suffered an allergic reaction to cosmetics? Do you think cosmetics companies should be forced to remove MI from their products? Leave your comments below...