03.Common chemicals and toxicity
Chemicals commonly found in cosmetic products
- Some nail polishes contain toluene – considered unsafe for use in cosmetics by the International Fragrance Association, because of its liver toxicity risk and possible contamination with benzene. Short-term effects of inhaling toluene can cause dizziness, euphoria, hallucinations and headaches – it’s what gives a “high” from glue and petrol sniffing. Manicurists are most susceptible to exposure.
- Dibutyl phthalate (DBP), found in some nail hardeners and nail polish, has been banned in Europe as an endocrine disrupting chemical.
- Mineral make-up and sunscreen (containing titanium dioxide or zinc oxide) may contain nanoparticles. These are new chemicals, and their safety is unknown.
- Some lipsticks contain BHA – on the banned and restricted fragrances list in Europe, and also classified as carcinogenic under California’s Proposition 65 law. It's presumed safety is based on estimates of typical consumption. While most of your intake is likely to come from food (it’s a permitted food additive in Australia), small amounts in lipsticks will add to the burden.
- DMDM hydantoin has been banned in Japan for use in products that aren’t washed away, and isn't considered safe by the Cosmetic Ingredient Review (CIR) for use in aerosol products. Yet we found it in baby wipes and hair products.
- Hair colour restorers may contain lead acetate – banned in Europe and Canada. It appears to be safe when used as directed, as there's no evidence significant quantities of lead are absorbed into the blood stream.
- Some anti-dandruff and anti-psoriasis shampoos contain coal tar, which has been banned in Europe and Canada. It’s a known carcinogen, but appears to be safe when use as directed in shampoos with no known cases of cancer arising from its use.
- Iodopropynyl butylcarbamate has been banned in aerosols in Japan, and considered unsafe by the CIR. It’s subject to concentration restrictions when used in leave-on products in Europe and Japan. We found it in baby wipes and hair products.
Challenging assumptions in toxicity testing
In the field of toxicology it’s often held that the dose makes the poison – that is, larger doses
have a stronger and/or faster effect than smaller ones. When scientists seek to find the dose at which a substance becomes toxic or lethal, they’ll often start with reasonably high doses and, if necessary, work backwards to find safe doses – where there’s no difference between the test and control animals.
However, over the last decade we’ve seen increasing evidence that very low doses of certain chemicals have an equally potent effect as high doses – much more so than a “medium” dose. The effect may be the same as the high-dose effect, where an intermediate dose shows no effect. Or, the effect may be different but equally problematic: for example, pregnant mice given large doses of an oestrogenic drug called diethylstilbestrol have extremely skinny offspring, while very low doses produce obese offspring.
Chemicals already found to have a low-dose effect include phthalates (banned in European toys and cosmetics), bisphenol A (being phased out or banned in North America) and pesticides such as endosulfan (banned in Europe, NZ and many other countries). These chemicals are still considered safe by Australian authorities, yet it’s becoming increasingly apparent substances assumed safe should be going back to the test lab for review.