I always read skincare labels. Why? Because I want to know what I am putting in my body. Yes that’s right, in, not just on, my body. While particle size, length of contact and skin quality all influence absorption of skincare products, your skin will definitely absorb some, if not all, of it. Unfortunately many commercial skincare products contain harmful ingredients, including:

Parabens: Probably one of the dirtiest words in skincare, parabens are a common preservative and broad-spectrum antimicrobial. They have been shown to interact with UV rays and potentially increase DNA damage and signs of ageing; they have also been found in breast cancer tissue, raising concerns they may play a contributing role.

Sodium lauryl sulphate (SLS): This foaming agent is a very irritating customer. A related surfactant, sodium laureth sulfate (SLES) has reportedly been found to have been contaminated with 1,4-dioxane, a probable human carcinogen, due to the manufacturing process, so this is one you want to avoid.

Nanoparticles: This relatively new technology, heavily used by the sunscreen industry, creates smaller particles of key ingredients to adapt a product's look and feel, e.g. zinc oxide nanoparticles make sunscreens look less 'white' on skin. Studies show nanoparticles create free radicals which damage cells, particularly in the presence of UV light, and not only play a role in skin ageing but also in cancer development. Choose sunscreens labelled ‘nano free’.

PEGs: Polyethylene glycols (PEGs) are substances which increase the absorption of a product into the skin. PEGs are generally followed by a number, e.g. PEG-101, which describes how many units of ethylene glycol are contained: the lower the number, the more easily the PEG is absorbed into skin. While PEGs themselves are not particularly hazardous, like SLES they can be contaminated with toxic chemicals and heavy metals. They also carry across other less welcome ingredients, like parabens and nanoparticles.

Artificial fragrances: Skincare manufacturers can use the broad terms ‘fragrance’ or ‘parfum’ to describe any one chemical that contributes to a product's scent. Protected by trade secret laws, this group of chemicals is thought to cause more allergic reactions than any other skincare product ingredient. Best stick to products which list natural fragrances, e.g. essential oils, so any potential allergen can be identified and avoided.

At the end of the day it’s really the great unknown. There is currently not enough evidence to say that these chemicals definitely have a negative effect on health, but it's better to be safe than sorry, protect your health, and choose natural and organic skincare products.

None of us want look back 10 years from now and say, “Why on earth did I use that, when there were so many other options?”

Naturopath Bridget Carmady has an interest in skincare, particularly ageing, acne and dermatitis. She is also founder of organic skincare brand Clémence Organics.