I get a lot of traffic to this blog from people interested in methylisothiazolinone, or as it is now known MI. For people who haven’t been following the story, here’s a quick recap. MI has been used for about 40 years in combination with a closely related chemical called methylchloroisothiazolinone. I’ll call that MCI. The combination works extremely well at very low levels. Its Achilles Heel is that it causes a lot of allergic reactions when used at higher levels. This took formulators a while to work out when it was first introduced. But the level was scaled down and the reactions went down.
Recently the use of MI alone has been approved. On paper this ought to cause fewer reactions, but following its adoption reactions have actually increased. This has led to dermatologists getting more people turning up with a reaction to MI and the MI/MCI mixture. This got picked up by the media in the UK who have made it into a mini-scare story. Someone has actually now started a petition to get the UK parliament to ban it, though it has not yet attracted many supporters.
But there is a problem here. The EU’s scientific committee, the SCCS, has looked at the issue and made some recommendations. The combination of MI/MCI will now be banned in leave on products, and the use of MI will not be permitted in products that are already using MI/MCI – not that I ever noticed a product that did this. The maximum use level has also been reduced for MI alone. These new rules come into force in June. (There is a further six months allowed for companies to comply with it.)
I am not sure that this ruling is particularly good news for anyone. If you have an MI allergy you will still have to look out for it in leave on products, and you’ll have to remember that it turns up in household and DIY products as well. But it means you’ll have more luck finding MI free moisturisers and the like. I wouldn’t plan a big binge at your local beauty counter though. MI is still theoretically permitted in leave on products – it is only the combination that is banned. In practice neither MI/MCI nor MI are used that much in leave on products anyway, so it may not make very much difference in practice.
If this new rule does lead to formulators switching away from MI and MI/MCI – which is quite likely because nobody likes to use materials with a bad image – then there may be some more options available for the MI sensitive.
For the vast majority of people who don’t have a problem with MI you can ignore the whole issue. There will be a small number of people who don’t react to MI who will react to the alternatives. Basically the problem will be switched from one small group of people to another – though luckily for the legislators there will be no way to know whether you fall into this group.
It is tempting to bring in bans and restrictions. But the more you restrict the number of preservatives that can be used, the fewer options there are out there and the bigger the problem sufferers have.
I think that the only sensible long term solution is to bring in clearer labelling of preservatives and extend it to all categories of consumer goods, not just cosmetics. You can work out what to avoid if you have a problem now, but the ingredient lists are hard to read for consumers who don’t happen to be chemists.
And here is the same story on my blog for professional beauty experts, with full practical details if you need to take action to comply with these regulations.