Methylisothiazolinone

That’s a bit of a mouthful, isn’t it? Methylisothiazolinone (MI), apart from being a word that I cannot pronounce, is a powerful biocide and preservative that stops products going off, so extending their shelf life. It’s used in toiletries, make-up, baby products and paint. Yes, paint… So it must be pretty strong stuff!

You might be wondering why I’m writing about MI. Well, a few times I have mentioned that my skin has been having some very nasty reactions to beauty products. I would put a product on my face and within minutes my skin would be red, swollen and itchy. It would take about a week to ten days for it to calm down each time, leaving me with a very sad, sore, dry and angry-looking face.

I had put it down to my skin simply being more sensitive during pregnancy. But then I thought, why is my skin only reacting to certain products and not others, why is it so random? And in the midst of this pregnancy fog it occurred to me that maybe it was a specific ingredient that was causing the problem. So, like the geek I am, I wrote out the ingredients list of the three products that had caused the reaction so far (Sisley Black Rose Cream Mask, Ginvera BB Creme and Clarins Cleansing Milk) and compared them to see if they had same ingredients.

Lo and behold, all three products had two ingredients in common. Glycerin was the first, but I knew that was unlikely to be causing such a problem. MI was the other ingredient, so I chucked it into Google and was astounded to discover that it is second only to nickel in causing contact allergies. Yet it’s on the ingredients list of so many products, big name products too, and is in a lot of baby products. Those of you with little ones might remember there being a bit of a fuss in the media last year about baby wipes causing painful rashes – MI is the ingredient they were talking about. It seems that I have developed an allergy to it.

I’m now having to thoroughly check all of my products to see if MI is on the ingredients list and have had to get rid of loads, including my beloved Aussie shampoo and conditioner. My partner thinks it’s great, he has inherited lots of wonderful skincare goodies that I now can’t use!

So there you go, it turns out that my skin isn’t just suffering from pregnancy-related sensitivity. It’s something specific. Perhaps if you too find yourself having random reactions to make-up or beauty products check the ingredients list and see if it contains methylisothiazolinone.