Ingredient Watch List: Iodopropynyl Butylcarbamate, the Toxic Preservative

Iodopropynyl Butylcarbamate

Well here we are talking about the potential problems with synthetic preservatives again! Iodopropynyl butylcarbamate (IPBC) is a water-based preservative which—get this—was used originally in the wood and paint industries. It's now also used in some cosmetics and personal care products. However, even the cosmetic industry admits that this ingredient is toxic, and restrictions have been placed on its use.

Here's why you may want to watch out for this one.

If you're using products with this toxic preservative, you may find yourself scratching irritated skin.

What is Iodopropynyl Butylcarbamate?

IPBC is a preservative that helps prevent mold, bacteria, and other germs from spreading in creams, lotions, and other products. It was used for years in paints, primers, and coolants, and only more recently in cosmetic products, as it is effective against a wide variety of microorganisms. You're likely to find it in foundations, concealers, bronzers, self-tanners, eye shadows, mascaras, makeup removers, shampoos, conditioners, shaving creams, diaper creams, anti-itch and rash creams, bath soaks, body washes, hair dyes, lip balms, and moisturizers.

Is It Safe?

IPBC is a suspected gastrointestinal and liver toxin, and is thought to present risks to human reproduction and development, having been linked to the potential for reduced fertility and increased risk of pregnancy problems. It's a suspected teratogen, which means that it may increase the risk of birth defects.

The Environmental Protection Agency notes that there is limited evidence of gastrointestinal and liver toxicity with IPBC, and Japan's Standards for Cosmetics restrict its use in cosmetics. Even the Cosmetic Ingredient Review (CIR) has expressed concerns about toxicity with IPBC, and limits the use in cosmetics to concentrations less than or equal to 0.1%. They noted that at concentrations of 0.5% and above, it has the potential to irritate skin, and because of the dangers of inhaling the chemical, they recommend it not be used in products meant to be aerosolized.

The European Union goes even further to limit the use of the preservative in cosmetics at a maximum concentration of 0.02% in rinse-off products, and 0.01% in leave-on products, except in deodorant/antiperspirant products, where the limit is even lower—0.0075%.

Proven to Increase Risks of Contact Allergies

The other main problem with IPBC is that it can increase your risk for contact dermatitis—skin allergies. According to 2003 patch-test study, IPBC is one of the new allergens. In 2008, British doctors noted allergic dermatitis in cleansing wipes. In a 2002 study, researchers stated that, “As the use of this seemingly safe preservative becomes vast, an increased number of cases of IPBC-induced contact allergy is likely.”

As more consumers have become aware of the potential dangers in preservatives like parabens, companies are looking for alternatives. Rather than use natural preservatives that don't present potential dangers, however, they're turning to options like IPBC. As we find it in more and more products, we're seeing more and more allergies.

Typical symptoms of an allergy to IPBC include redness, swelling, itching, and fluid-filled blisters. It's important to be aware that the symptoms may not develop for several days after exposure to the ingredient. Patch tests can help you determine if you may suffer from an IPBC allergy.

Safer, More Nourishing Choices

To avoid this preservative, watch for the following on your products:

  • IBP
  • IPBC
  • Butyl-3-iodo-2-propynylcarbamate
  • Carbamic acid
  • Glycacil®

There are all sorts of natural alternatives to chemicals like these that don't subject you to health risks. These include thyme, vitamin E, vitamin C, and even lavender and rosemary. Plus these ingredients provide skin benefits on their own, as well as preserving the formula, so why would you use anything else?

Have you gotten rid of products with IPBC? Did you experience an allergy from it? Please share your story.

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Badreshia, S; Marks Jr, JG (2002). “Iodopropynyl butylcarbamate”. American journal of contact dermatitis 13 (2): 77–9. PMID 12022126.

Badreshia S, Marks JG Jr., “Iodopropynyl butylcarbamate,” Am J Contact Dermat. 2002 Jun;13(2):77-9.,

“Iodopropynyl Butylcarbamate,” English Articles, June 9, 2010,

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Reader Interactions


  1. Justin says

    Everything is toxic at some level. Even water. If you use too much of anything, natural OR synthetic, it will cause problems. This is why the cosmetic industry restricts the usage to a safe amount. It’s much safer to use products with a good preservative than products that don’t have one. You should also talk about the dangers of different microbes and fungi that naturally grow in products that haven’t been adequately preserved if this is about the safety of your readers.

    There is no conspiracy to poison you. We put preservatives in products to keep you from getting sick. That being said, I myself am always trying to find the safest ingredients for my customers. If you want products that don’t have preservatives, make them at home, and remember that if it has water in it, it will probably only be safe to use for a few days to a few weeks at the most.

  2. Pamela Thomas says

    I started breaking out two years ago first on my arm then to my legs and from there to my abdomen and then thighs. I went to doctors for over a year. PCP, Dermatologist and finally went to allergist and through a week long patch test found out that I was allergic to this chemical. My allergist provided me with a 182 page booklet that has products that have been tested and do not have this chemical in it. I was put on steroids by mouth and cream and antibiotics. I now take two zyrtec daily and use my list like my bible to stay away from this chemical. After five months of being very strict with what I come in contact with most of my rashes have cleared up except for one leg. I have scars over both my lower legs and my arms from this “rash from hell” which is the name I gave it. Beware, everything, I mean everything that is in our daily household items has this chemical in it. I am down to very exact and strict items that I can use. An example is some of the Tide brand clothes detergents have it and some very specific ones don’t. So it is not a brand issue, it is a product issue. I have had to make sure even my toothpast and my mouthwash is on my list, which is products without this chemical.

  3. Anita Burkett says

    I just found out I have a bad Allergy to this and received a long list of ingredients safe to us,but is there a list anywhere of any of the high end cosmetic anti aging and makeup that has it in it so I know what to stay away from?
    At this rate it is going to take every minute of my life to find what is safe to use? Very frustrated and would love any advice about how to attack this problem next? Thanks

  4. Amy Waxham says

    I was just diagnosed with this allergy today and I am feel a very daunting task ahead of me to find products that will be safe for me to use. I have had contact dermatitis symptoms for the past 18 years. I am so very glad to finally know what is causing my inflammations. How do I get my hands on a list of products to avoid or products to use? I need these asap. I would love some help figuring this out.

    • Mary Gebrin says

      I was just diagnosed today, June 25, 2015!! I have suffered so much!! PLEASE if you get this list of products to avoid (I don’t care how long it is!) could you pass it on to me??

  5. deb says


    I came upon this discussion today because i have been diagnosed with this allergy. Any suggestions for safe products or resources we can access? Thanks! Debie

  6. monica says

    thanks for the details which you have written ,so please can u tell me some shampoo, facewash,toothpaste which can i use sls,paraben,ipbc free .
    I stay in india so plz tell me the some natural product which can i use .
    And i have oily skin and my hair has dandruff scalp.

  7. laurie says

    This has cause more than a decade of problems for me. The skin on the tips of my first four fingers on both hands peels and peels to the point of bleeding. I could not do any housework (including folding laundry) without gloves, I hand two bandaids on each finger to hold various ointments on, I showered and washed my face wearing rubber gloves. I searched and bought new hand creams and I would use anything I can find–now I realize that most of them have IPBC! I found out after skin testing that I am allergic and as soon as I limited my products, it stopped. A recent flair up must be due to new make up or shampoo, it is hard to read those tiny labels!

  8. KaityPerry says

    I have a skin allergy to IPBC. For 12 years I was diagnosed with contact dermititis, dandruff, and athletes foot. Which all turned out to be caused by the IPBC allergy. It’s in EVERYTHING. Shoes, clothes, body wash, shampoo, conditioner, make up, laundry/dish soap. It’s even used in making the band for my fitness tracker! I’m so annoyed with this allergy.

    • Susan Hadlow says

      Really in fitbit band? I sure would like a list of what does not contain this nasty chemical. I have been diagnosed with a allergic reaction to it. After 20 years of fighting the rash and sores on my hands the allergist found I am allergic.

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