T

Talc A finely-ground mineral (from magnesium silicate) which is used as the base for many pressed and loose powders, eyeshadows, etc. As we explain in The Green Beauty Bible: ‘ You probably had it rubbed into your derrière as a baby. As a grown-up you’ve probably applied it to your face, because it’s a common ingredient in make-up. Many natural brands avoid it, however, because it can be contaminated with potentially carcinogenic asbestos. But it’s not that straightforward. The super-natural German brand Logona, for instance, does use talc – but each batch is first certified by an independent lab to be asbestos-free. If you’re concerned about talc in your make-up, e-mail the company that makes it for their policy on sourcing and testing talc.’

Tetradibutyl pentaerithrityl hydroxyhydrocinnamate A synthetic ingredient in the Cinnamate family, used in foundations, sun protection, moisturisers etc.; C innamates can be allergenic.

Tetrahexyldecyl ascorbate A vitamin-C-derived antioxidant and skin-conditioning ingredient.

Tetrasodium EDTA This synthetic ingredient is what’s known as a ‘chelating agent’, used to soften water; it bonds with minerals which promote microbial growth, so it acts as a preservative.

Thymol Obtained from essential oils of thyme, lavender and oregano, this has to be listed on labels because it can cause allergic reactions.

Titanium dioxide (CI 77891) Incredibly widely used in powders, foundations, sun protection etc. (over 7,000 products on the Environmental Working Group’s Skin Deep Cosmetic Database contain Titanium dioxide). It occurs naturally as a mineral. Larger particles of Titanium dioxide sit on the skin’s surface, bouncing light off - and so helping to prevent against sun damage. However, according to the Skin Deep database, over 70% of sunscreens featuring this ingredient feature nano-particles - tiny particles which may not only sit on the surface but can potentially more readily penetrate the skin, and which have health question marks over them simply because nobody knows the long-term effects of exposure, or whether there is a risk of toxicity or build-up in the organs. (Nanotechnology is a relatively new science.) In The Green Beauty Biblewe list several sunscreen products which, so manufacturers promise, do not contain nano-particles.

Tocopoheryl acetate A form of vitamin E.

Tribehenin Derived from Glycerine and Behenic acid, and used as a skin conditioner in cleansers, sun protection, etc.

Tricalcium phosphate Used in toothpastes and also as an anti-caking agent, and as a dietary supplement;

Trideceth-9 See Polyethylene Glycols (PEGS).

Triethoxycaprylysilane A synthetic ingredient that functions as a binding agent and emulsifier (see Silicone), and is used in sunscreens, moisturisers, etc.

Triethanolamine (TEA) This ingredient is used as a pH balancer in cosmetic preparations in a variety of different products - ranging from skin lotion, eye gels, moisturizers, shampoos, shaving foams etc. As with any amines, it may have the potential to create nitrosamines, but with the low concentrations used in cosmetic products the chances of that happening is very slim and it is further theorized that nitrosamines cannot penetrate the skin.

Triethyl citrate Citric acid, also used as a food ingredient to prevent rancidity.

Triheptanoin Skin conditioning and emollient originally derived from grapes; one study suggested that this ingredient is a penetration enhancer which may make it easier for other ingredients to penetrate the skin.

Trihydroxystearin Mostly used as a thickener and skin conditioner, derived from Glycerine and Hydroxystearic acid (see Stearic acid).

Trimyristin Synthetic or semi-synthetic ingredient which is used as a moisturiser and emollient; some Myristates are comedogenic, meaning they may block pores and trigger acne.

Trioctyldodecyl citrate See Citric acid and Lauric acid, which are the sources of the ingredient.

Trisodium ethylenediamine disuccinate A naturally-derived chelating agent. Some animal tests show effects on the reproductive and nervous (as well as irritation) at high doses (and no, we do not approve of animal testing IN ANY FORM!); however, according to the Environmental Working Group’s Skin Deep Cosmetic Safety Database, this is a ‘Low hazard’ (it scores 1/10).

Trisodium HEDTA A preservative; there is some suggestion this may act as a penetration enhancer, which may make it easier for other ingredients to penetrate the skin.

Tromethamine A synthetic ingredient used mostly to maintain a product’s pH; as with any amines, it may have the potential to create nitrosamines (which can be carcinogenic) - but with the low concentrations used in cosmetic products the chances of that happening is very slim and it is further theorized that nitrosamines cannot penetrate the skin.

Tromethamine stearate See above.