Did You Know a Common Wet-Wipe Preservative Caused an Allergy Epidemic?
Methylisothiazolinone (MI) in wipes and washes drove a wave of contact allergy in the 2010s. What it is, why leave-on exposure made it worse, what changed, and what to look for on the label.
The fact, stated plainly
In the early 2010s, dermatologists across the UK and Europe reported a sharp rise in contact allergy traced largely to methylisothiazolinone (MI), a preservative that had been increased in cosmetics and, notably, wet wipes, including baby wipes. It became common enough that specialists described it as an epidemic of contact dermatitis, and it is one of the clearest recent examples of how a single ingredient can quietly affect a lot of people.
Why it happened
Preservatives are necessary in water-based products to stop bacteria and mould growing. When an older preservative combination fell out of favour, MI was used more widely and at higher concentrations to fill the gap, including in leave-on products and wipes. The trouble is that MI is a fairly potent sensitiser, meaning it is good at teaching the immune system to react to it. Combine a potent sensitiser with frequent, leave-on skin contact and you have the conditions for a wave of new allergies, which is exactly what unfolded.
Why it mattered
Wipes leave the preservative on the skin, they are not rinsed off, and they were used frequently: on babies’ bottoms, on faces, for make-up removal. So a lot of skin was exposed a lot of the time. After the problem was recognised, regulators restricted MI in leave-on products, and rates began to fall, but it still appears in some rinse-off products, such as certain shampoos and washes, and in household items like cleaning wipes. Once someone is sensitised, even the smaller amounts in rinse-off products can keep a reaction going.
Who it affects most
Anyone who uses wipes or washes frequently, and people with an already-compromised skin barrier, such as those with eczema, who absorb more of what is applied. Babies and young children were especially affected during the peak because of how often wipes are used on them. People sensitised years ago may still react today whenever they meet MI.
How to spot it on a label
- Look for methylisothiazolinone (MI) and its close relative methylchloroisothiazolinone (MCI), often listed together as a pair.
- Check rinse-off products too, MI is more restricted in leave-on items but still allowed in some wash-off ones.
- Do not forget household products: surface wipes and some cleaning liquids contain it.
- A rash that matches where a wipe or wash is used, around the mouth, bottom, hands or eyelids, is a clue worth following. Our methylisothiazolinone guide has more.
What to do about it
If you get unexplained dermatitis from wipes, washes or shampoos, check the label for MI and MCI. For babies and reactive skin, plain water and a soft cloth, or a confirmed MI-free wipe, is a safe default. Introduce any new product gradually and stop at the first sign of redness or itching. Our MI-free wet wipes list is a useful shortcut.
When to see a professional
See your GP or pharmacist if a suspected reaction is weeping, spreading or not settling once you stop the product, as it may need treatment. Ask about a dermatology referral and patch testing if a contact rash keeps recurring without an obvious cause, since patch testing is the reliable way to confirm MI allergy and identify anything else you react to at the same time.
Check it against your own list
A free tool like Skincarisma or INCIDecoder lets you check a product’s ingredients, but not whether it contains your triggers. A personal-list app like ClearaScan lets you save MI and your other triggers once and scan any product, cosmetic, food or medication, against your ingredient guard list, flagging only yours. It also keeps a Reaction Journal, a shared Care Circle so a parent or carer can scan for you, and a Trusted Products list, and it is currently in early access. (Disclosure: our editor co-founded ClearaScan, and we are not paid to mention the others.)
The Sensitive Skin Ingredient Decoder
A free one-page guide to reading a skincare label fast: the irritants to watch, the fragrance loopholes, and what "fragrance-free" and "hypoallergenic" really mean.
Common questions
What is methylisothiazolinone (MI)?
MI is a preservative used to stop bacteria and mould growing in water-based products such as wipes, shampoos and washes. It is effective, but it became a common cause of contact allergy when its use was increased in the 2010s.
Why did wipes cause so many reactions?
Wipes leave the preservative on the skin rather than rinsing it off, and they were used often, on babies' bottoms, on faces and for make-up removal. That meant frequent, prolonged skin contact, which is exactly what drives contact allergy.
Has MI been banned?
Not banned, but restricted. After the problem was recognised, regulators restricted MI in leave-on products, and reaction rates began to fall. It still appears in some rinse-off products and household items, so label-checking still matters.
What should I look for on a label?
Look for methylisothiazolinone (MI) and its close relative methylchloroisothiazolinone (MCI), which are often listed together. If you react to wipes, washes or shampoos, these are the names to check for.
What is a safe option for babies?
For babies and reactive skin, plain water and a soft cloth, or a confirmed MI-free wipe, is a safe default. If a rash appears where wipes are used, switching to water is a sensible first step.