Dermatology Made Easy is based on the most popular topics from DermNet NZ's vast array of material. The book combines the essential focus of the ‘Made Easy’ book series with the authority and knowledge base of DermNet NZ's unparalleled resources.
Author: Vanessa Ngan, Staff Writer, 2012.
Iodopropynyl butylcarbamate (IPBC) is a water-based preservative agent that comes from the carbamate chemical family. It has been used for years as a preservative in water-based paints, metal-working fluids and as a wood preservative. More recently it has been used as a preservative in cosmetics products, where it is found to be effective against a wide variety of microorganisms.
|Products commonly containing iodopropynyl butylcarbamate|
|Cosmetics||Pharmaceutical/self-hygiene products||Industrial products|
Although iodopropynyl butylcarbamate has claimed to be safe when used at concentrations less than 0.1%, its widespread use in cosmetic products has led to an increased number of cases of iodopropynyl butylcarbamate-induced contact allergy. In addition, there are concerns that it is acutely toxic by inhalation and therefore should not be used in aerosolized or inhaled products.
Countries around the world have in place regulatory standards that define the concentrations, limitations and requirements for the use of preservatives in cosmetic products. For example, in New Zealand the cosmetic standards state that iodopropynyl butylcarbamate is not to be used in oral hygiene and lip care products; not to be used in preparations for children under 3 years, except below certain levels in bath products/shower gels and shampoos; and not to be used in body lotion and body cream (concerns because application is on a large part of the body).
Typical allergic contact dermatitis may occur. It may take several days after exposure to the allergen for symptoms to appear. Typical symptoms include redness, swelling, itching, and fluid-filled blisters. Patients commonly present with a scattered generalized dermatitis or dermatitis affecting hands and arms.
Another concern of iodopropynyl butylcarbamate is that it may have adverse effects on the immune system. It is also suspected to be an environmental toxin. Further research into these areas is necessary.
Iodopropynyl butylcarbamate allergy is diagnosed from the clinical history and by performing special allergy tests, i.e. patch tests. Patch testing with 0.2% iodopropynyl butylcarbamate in petrolatum is used.
Self-testing a product for iodopropynyl butylcarbamate is possible but should be done only after first talking with your doctor. This should be done only with products that are designed to stay on the skin such as cosmetics (not including eyeliners or mascaras) and lotions. Apply a small amount of the product to a small tender area of skin such as the bend of your arm twice a day for 1 week. Examine the area each day and if no reaction occurs, repeat the test on a small area in front of your ear. If no reaction occurs, it is unlikely you are allergic to it.
Products such as shampoos and cleansers (rinse-off products) should not be tested in this way as they may cause an irritant contact dermatitis, which is not allergic, if they are covered or overused on tender areas.
If you are diagnosed with iodopropynyl butylcarbamate allergy then avoid exposure to iodopropynyl butylcarbamate-containing products.
Once the dermatitis appears on the skin, treatment is as for any acute dermatitis/eczema, i.e. topical corticosteroids, emollients, treatment of any secondary bacterial infection (Staphylococcus aureus), etc.
Read product labels and avoid products that contain iodopropynyl butylcarbamate or any of its alternative names. Preparations that contain other types of preservatives, as long as you do not have an allergy to these too, should be safe to use. Ask your pharmacist for advice.
Alert your doctor to the fact that you have an allergy to iodopropynyl butylcarbamate. Your dermatologist may have further specific advice, particularly if you are highly sensitive.
Iodopropynyl butylcarbamate is also known by several other names. These include:
CAS number: 55406-53-6
Sensitiser: iodopropynyl butylcarbamate
Patch Test: 0.2% iodopropynyl butylcarbamate in petrolatum
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