MI in Paint

MI in paint

One of the most surprising things about blogging is how much you learn.  A good example arrived in my inbox yesterday.  I have just started a newsletter for people with sensitive skin, largely because I get a lot of people getting in touch looking for information about it, and in particular sensitivity to methylisothiazolinone or MI.  This is of course of no interest at all to the 99.9% people who don’t have a problem with it, so I thought a newsletter was a good way of giving them the information they want without devoting too many blog posts to it.  But a list member drew my attention to something simply too interesting not to share it.

I am probably the worst person in the world to talk about paint formulations.  Paint isn’t much like cosmetics, but there are some common features.  We use some of the same techniques and similar raw materials.  So as a cosmetic chemist I sometimes run into the simple but honest folk who formulate paints at conferences and trade shows.  So I am vaguely aware that there are some paints that need to be preserved from microbial contamination.  I wouldn’t have guessed that they use MI for this purpose, but I can imagine that it would probably work quite well.  So I wasn’t surprised to hear that it is used in paints.  And if your painting technique is anything like mine, you can easily see how that would lead to problems for people with an MI sensitivity while painting.

What was much less obvious was what would happen as the paint dries.  My respondent found that she reacted to the atmosphere in the rooms once they were painted.  As the paint dried the preservative dried out as well and contaminated the air.  She did some research and it turns out that while this is a rare problem, she was not alone.  Other people had had the same experience.  She also found a solution.  The MI on the walls can be neutralised with sodium bisulphite, as detailed in a paper in the journal Contact Dermatitis.

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It is a shame that the same rules about disclosure of ingredients don’t apply to household products in the same way that they do to cosmetics, so people can be pre-warned of the hazards.  In fact, on a practical level I think the optimum approach would be to list preservatives and only preservatives on everything.  I find really long cosmetic ingredient listings confusing and I’m a chemist.  I am sure there are many members of the public who would much prefer it if only materials that are likely to cause problems were put on packs.  And whatever the system, it makes most sense for it to be applied universally.

But anyway, thanks to Christine for teaching me something.  If you are interested in sensitive skin and you haven’t yet signed up for my newsletter on the subject you can do so here.

Sensitive Skin Newsletter

 

Airborne contact dermatitis from methylchloroisothiazolinone in wall paint. Abolition of symptoms by chemical allergen inactivation

 

This entry was posted in Health, Ingredients, Preservatives and tagged , . Bookmark the permalink.

5 Responses to MI in Paint

  1. M says:

    I too wish there was proper disclosure. It took me many years to realise that the rash on the top of my feet was linked to Mr Sheen. It only happened in summertime and one day I noticed that the spray settled out onto my bare feet. Sure enough, 48 hours later (typical allergic response time) the rash developed. I contacted the company and the spray contains colophony to which I am allergic. Problem solved. But it would have been SO much easier if the can had been labelled.

    Thanks for the interesting post. I quite like it when you go off topic.

  2. John Dodds says:

    Tonight, 14th May, 14, I was watching Tv when their was an item about a rash a woman had on her face after using paint purchased at B & Q. I had been using B & Q emulsion paint and when I got out of bed I had a deep red rash on my throat and chest. I was quite worried about it as it was bad. However, I treated it with Eumovate. I have been left with red spots on my chest which will not heal so far. I would not have suspected the paint but for the item on TV. All windows were open.

  3. Colin says:

    Hello John, that does sound like an MI reaction. But there are other ingredients in paint so it isn’t conclusive unless you get a patch test. Sensitivity to MI is nowhere near as widespread as you’d imagine from the coverage on Watchdog.

  4. Bonnie says:

    Hi Colin. I have just been tested positive for MI and have literally just had the whole of the downstairs of my property painted!! I have sore red patches of dry skin all over my face and the top half of my chest. You say that the paint can be neutralised with Sodium Bisulphate. Can this be treated after painting, what is the process and how does this work? Any help and information that you can give me will be massively appreciated.

    Thank you.

  5. Colin says:

    Hi Bonnie,

    I have never done this myself – I have passed on everything that I was told in the blog post.

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