These are widely used preservatives. Diazolidinyl Urea is a known carcinogen, as well as causing allergic reactions, dermatitis and many other problems. Both these chemicals release formaldehyde, which can be toxic and a carcinogen in its own right.

Triethanolamine and diethanolamine are widely used in cosmetics as emulsifiers and/or foaming agents (giving a creamy texture). They can cause allergic reactions, eye irritation and dryness of hair and skin. DEA and TEA can form cancer-causing nitrosamines when they come in contact with nitrates. They are toxic if absorbed into the body over a long period of time. Triethanolamine is used in the manufacture of a type of mustard gas for chemical warfare.

Parabens are widely used in the cosmetics industry as bacteriocides (inhibitors of microbial growth) and as preservatives (extending product shelf life). They have been used for many years but recently concerns over their usage have grown. Have caused many allergic reactions and skin rashes in a small percentage of people. Studies have shown parabens can be weakly estrogenic (function like estrogen) and can be absorbed by the body through the skin.

This oil derivative is used for its emollient (softening and smoothing) properties in cosmetics, as well as for its healing properties on cuts and grazes (such as Vaseline). It has no nutrient value for the skin and can interfere with the body's own natural moisturizing mechanism, leading to dryness and chapping.

A petroleum-derived chemical used in hairsprays, styling aids and other cosmetics. It is considered toxic, since inhaled particles can damage the lungs.

Also known as Sodium Lauryl Sulphate or Sulfate, this detergent (surfactant) is used in shampoos for its cleansing and foam-building properties.

Stearalkonium chloride is a compound used in hair conditioners and creams to reduce static electricity and make it easier to comb through hair. Developed by the fabric industry as a fabric softener, it is a lot cheaper and easier to use in hair conditioning formulas than proteins or herbals, which are beneficial to the hair.

Used to make cosmetics "pretty," synthetic colors, along with synthetic hair dyes, should be avoided at all costs. For US products they will be labelled as FD&C (Food, Drugs & Cosmetics, in reference to the US Federal Act) or D&C, followed by a color and a number. Example: FD&C Red No. 6 / D&C Green No. 6.

Synthetic fragrances used in cosmetics can have as many as 200 ingredients. The individual chemicals are not identified: the label will simply read "fragrance." Some problems caused by these chemicals include headaches, dizziness, rash, hyperpigmentation, violent coughing, vomiting and skin irritation.

Synthetic musks are chemicals used in perfumes, soaps, laundry detergents, fabric softeners and cosmetics which can disrupt hormones – try to find products with alternatives like citronella, or use fragrance free products.

Synthetic musks have until recently been considered non-toxic, but opinion is changing. At the very least, they adversely affect the body's ability to cope with toxic compounds.