Propylene Glycol aka 1,2-dihydroxypropane, 1,2-propanediol, Methyl Glycol, PG, PPG, and Trimethyl Glycol. Propylene Glycol is commonly found in lipsticks, sunscreen, and facial cleansers. Its purpose in these products is to maintain the moisture content. Though it can be derived naturally it is typically synthetically derived. This chemical can also be used as an antifreeze. It has been linked to contact dermatitis and other skin irritations, as well as having observed effects on the kidneys and respiratory system. This ingredient may be toxic to the central nervous system from inhalation. This ingredient typically isn’t high on the ingredient list but you should still exercise caution.
Polyethylene Glycol aka PEG. It is commonly found in skin creams. PEG can penetrate the skin and bring other substances with it, so be mindful of that if you use a product that contains this ingredient. PEG may cause slight skin irritance, though it is not typically considered an irritant. Concentrations in many cosmetics are not likely to cause these impacts.
-Ethanolamines aka DEA (Diethanolamine), TEA (Triethanolamine) and MEA (Monoethanolamine), Cocamide DEA, Cocamide MEA, DEA-Cetyl Phosphate, DEA Oleth-3 Phosphate, Lauramide DEA, Linoleamide MEA, Myristamide DEA, Oleamide DEA, Stearamide MEA, TEA-Lauryl Sulfate. -Ethanolamines are amino alcohols and can be found in shampoos and other personal care products. Released into the environment they can have a high biological oxygen demand, though concentrations in personal care products are unlikely to be enough to cause this (though it is dependent on various other factors including water treatment). MEA can also be toxic to various aquatic organisms at low-medium concentrations; DEA can be toxic at medium-high concentrations. They can be toxic if absorbed by the skin (concentrations in cosmetics are not likely to be high enough). Though links to cancer have been made for DEA to lab animals, the same conclusions have not been made for humans.
Preservatives aka Methylisothiazolinone, Methylchloroisothiazolinone. These are preservatives within the isothiazolinone group that have been used for their antibacterial and antifungal properties. This ingredient can be found in foundations, eyeliners, mascaras, lotions and creams, and soaps, among others. These are typically the last ingredients listed, therefore concentrations are typically low. Both ingredients have been linked to allergic contact dermatitis and reported incidences of allergies have increased with methylisothiazolinone being named contact allergen of the year in 2013.
Beware!/Avoid! (These ingredients do not qualify to be exclusively ‘Avoid!’ but have more information than ingredients listed ‘Beware!’)
Triclosan. It used an an antibacterial and antifungal agent in personal care products such as soaps, toothpaste, deodorants, lip balms, and some cosmetics. Triclosan is under review by the FDA based on various scientific studies that have indicated that the chemical may be a hormone (endocrine system) disruptor, and may contribute to making bacteria antibiotic resistant. Triclosan is also suspected to bioaccumlate (increase in concentration in fatty tissues), and has been detected in breast milk. It is also suspected to be harmful to the immune system. Triclosan is banned in the EU in concentrations over 0.3 percent, at this time I am not certain of the concentrations used in the aforementioned products.
Phthalates aka Dibutyl Phthalate (DBP), diethylphthalate (DEP), dimethylphthalate (DMP), Butyl Benzyl Phthalate (BBP), Di(2-ethylhexyl)phthalate (DEHP). Phthalates are typically used as plasticizers, and were common in nail polish, lotions, fragrances, and some hair sprays. According to the FDA, phthalates are considered ‘safe’ in adults, though phthalate usage has declined in cosmetics since 2004 likely due to consumer pressure. Phthalates are suspected to cause damage to the liver, lungs, heart, and kidneys, as well as negatively impact development and reproduction in animals. Similar impacts in humans have yet to be observed. DEP is the most commonly used presently.
Stearalkonium Chloride. This ingredient is an ammonium salt and is most commonly found in hair conditioners and acts as a conditioner, anti-static agent, and softener. It was originally used by the fabric industry for use as a softener. This ingredient can be an irritant at high concentrations. It is not suspected to be toxic at the levels used in conditioners.