Formaldehyde and formaldehyde releasers
what it is: Formaldehyde is a strong-smelling chemical that is used to lengthen the shelf-life of some cosmetics, hair straighteners and nail polishes. Some companies have started moving away from formaldehyde use, but other preservatives that prevent the growth of bacteria in water-based personal care products — like shampoos and liquid baby soaps — can still release formaldehyde gas over time. These include DMDM hydantoin, diazolidinyl urea, glyoxal, sodium hydroxymethylglycinate and quaternium-15.
What the research says: Exposure to low levels of formaldehyde fumes is known to irritate the eyes, nose and throat, while higher exposures, particularly over longer periods of time, have been linked to nose and throat cancers as well as other ailments in certain workers, such as hair stylists and manicurists. Formaldehyde, paraformaldehyde and quaternium-15 are included in California and Maryland’s bans.
what it is: Fragrance formulas are considered trade secrets, which means companies can hide any number of chemical ingredients under the umbrella terms “fragrance” or “parfum.” A product’s label can say “unscented” and still have one of these terms in the ingredient list because some fragrance compounds may be used as dyes, solvents or stabilizers for active ingredients or for masking other undesirable smells in a product.
What the research says: According to the International Fragrance Association, there are more than 3,600 chemicals used in fragrance mixtures around the world. These include chemicals that environmental exposure researchers and toxicologists agree should be avoided, such as benzophenone, BHA, naphthalene and phthalates. Other ingredients in fragrances can trigger skin allergies, eczema, nasal irritation and asthma. Studies on some of the chemicals in fragrances, such as diethyl phthalate and musk ketones, have also suggested that they can interrupt normal hormone function, which has been linked to ovarian failure and sperm damage.
Isobutane, propane and other propellants
what it is: Isobutane is a component of natural gas and crude oil that is commonly used as a propellant in aerosol sprays like many of the dry shampoos, sunscreens and deodorants that were recently recalled. Isobutane is not typically of concern on its own, but benzene, a known carcinogen that is also found in crude oil, has frequently been found to contaminate it and other petroleum-derived propellants like butane and propane.
What the research says: According to the WHO, there is “no safe level of exposure” to benzene in the air we breathe. In the short term, high levels of benzene can cause headaches, dizziness, vomiting and a rapid heart rate. Chronic exposure can have more severe effects, slowing down the production of red blood cells and damaging white blood cells critical to the immune system. Studies have also shown that benzene exposure causes several types of leukemias.