Isothiazolinone test kits, dish soaps and cosmetics

A new published paper stopped me in my tracks recently — Isothiazolinone Detection in Dish Soap and Personal Care Products: Comparison of Lovibond Isothiazolinone Test Kit and Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry.

There’s an isothiazolinone test kit? Who knew? 

According to its manufacturers, the test kit is designed for “cooling water” and “disinfection control” — in order, I presume, to check you’re using enough isothiazolinone to control bacteria, but not so much that you’re releasing unsafe / illegal quantities into the environment in your waste water. 

But according to the published paper in the journal Dermatitis, “The Lovibond Isothiazolinone Test Kit (LITK) has been reported to successfully identify clinically relevant, occult isothiazolinones in patient personal care products” — and it is this claim which was examined by the researchers, although I do not know where it has been ‘reported’. 

Although few products were tested and compared by the US-based team, it seems the LITK is extremely poor at detecting isothiazolinones in dish soap / cosmetic products, giving many false positives. This should perhaps hardly surprise — it was not designed for this purpose.

The real story here arguably is that highly accurate Mass Spectometry techniques identified three positive isothiazolinone cases — one each of MI, MCI and MI/MCI — in dish soaps where no isothiazolinone content was declared. Given nine supposedly isothiazolinone-free dish soaps were tested, it is extremely concerning that around a third of dish soaps could harbour MI or MCI and pose a risk to unsuspecting consumers, both already allergic and who may be at risk of becoming sensitised.

“Personal care products may contain undeclared isothiazolinones” conclude the authors. Indeed. And the same goes for household detergents, clearly. But what should be done about it?

Seems to me that the authorities in the US should be conducting far, far more spot checks on products on the market …

Testing kits

Testing kits, by the way, do exist for some allergens — people with nickel and cobalt allergies, for example, may well be familiar with the many affordable chemical spot test kits such as Nickel Alert that they can use to help them identify leaching metal ions in everyday objects — but a functioning and reliable and easy-to-use kit for those with isothiazolinone allergy would be a game changer.

The LITK clearly isn’t it, though, and was designed for a very specific purpose, for which I have no doubt works very well indeed. And given that it appears to retail at around $200, a product of that cost range would be out of the budget of many if a similar kit could be devised for isothiazolinone avoiders. I don’t know whether there are people working on an affordable test-at-home kit, but I sincerely hope so … 

13 Comments

  1. Carolyn Evans

    Are Lush Products okay

    Reply
    1. MI Free (Post author)

      They say that they don’t use MI / MCI, so in theory yes. Depends on any other sensitivities you have, however.

      Reply
      1. Judy

        Dr. Bronner’s is a great brand. I highly recommend it.

        Reply
        1. MI Free (Post author)

          Yes, I agree. Lots of solid multi purpose products. Do you use fragrance oils, which can irritate some, but I think they have some fragrance free options.

          Reply
  2. Norman Crofts

    How persistent are isothiazolinones in fabrics and on surfaces etc and can they be cleared by rinsing in water? A home must have many places where they exist from unknowing past use of cleaning materials.

    Reply
    1. MI Free (Post author)

      They can be cleared by rinsing, yes (a couple of studies show that sufficient rinsing of isothiazolinone-containing laundry washes will get rid of it to the point where it can no longer be detected – although anecdotally many say they react to e.g. sheets washed in unsafe detergents, so still think this needs to be looked into more). They persist in painted walls for up to several months. I imagine they disperse from surfaces quicker. They do biodegrade.

      Reply
      1. Linda

        Aside from MI allergy I recently started “itching” all over my body. No rash just redness and I scratch so hard my body is covered in bruises. A new dermatologist[sp?] didn’t do a patch test but by the time I saw him I’d already taken pro-active steps. I washed everything [bedding, towels, all clothing] with Vinegar! Yes. Vinegar. I’ve used it for years to clean windows, floors, etc., so why not? Mixed with hot water in wash tub [2 cups] then rinse cycle removes odor. He did stress, no more Dryer Sheets! Not sure why but I hadn’t used them and with Sarna Cream [OTC]I’m doing better!

        Reply
        1. MI Free (Post author)

          Great news! I think vinegar does work as a fabric softener.

          Reply
  3. Linda

    When I first learned of my MI allergy my daughter Googled it to see what products contained it. She printed a 36 page (6 point font) list of just about everything I’d been using! Then I looked for products that were MI Free. Not as easy and so many products not found in the US. Most products don’t list it on their list of ingredients so it takes a lot of research.

    Reply
    1. MI Free (Post author)

      Cosmetics should list it, but other household detergents may not be as transparent, although they too should do so. It’s paints which are arguably the trickiest, in terms of commonly used products.

      Reply
  4. Elizabeth Kaul

    PERIOD that stuff is in everything. I got a 50 page printout, Now I know what ai can use for my skin hair laundry I was clear for 6 months broke my wrist whatever they put on my skin plus Prednisone 10mg it triggered my rash and hives worse than before Now I have to go twice a week for treatment “light in the box” it did work before .The doctors have no idea I have suffered for 4 years itching and hives,come on there has to be a answer?? I am 80 years old and very good skin took care of it all my life.

    Reply
    1. MI Free (Post author)

      I guess the ultimate ‘answer’ would be the development of new allergy-safe preservatives, meaning the isothiazolinones are no longer needed or can be dispensed with.

      Reply
      1. Norman Crofts

        It just shows how tricky is. Although I have done everything that I can think of to avoid contact with benzisothiasolinone I am still suffering reactions. I even went as far as asking my local water company whether their tap water was polluted with it but they replied that they did not test for it and they were not legally obliged to. It is just so difficult to find where it is, or other similar preservatives

        Reply

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