Hazardous chemicals to avoid in cosmetics and why


These are preservatives used in a wide variety of cosmetics to prevent the growth of microbes.

Where found:  Moisturisers, foundations, hair care products and shaving creams.  They are also used as fragrance ingredients but consumers won’t find it listed on the label.  Labels must contain the word fragrance but not the details as to what the fragrance contains.  Watch out for any ingredient ending in paraben.

Why to avoid:  Parabens are suspected of interfering with hormone function and can mimic estrogen. They can interfere with male and female reproductive functions.  In addition, studies indicate that methylparaben applied on the skin reacts with UVB leading to increased skin aging and DNA damage.

Synthetic fragrance and parfum

Used to produce a pleasant scent, the term ‘fragrance’or ‘parfum’ on a cosmetic ingredients list usually hides a complex mixture of dozens of undisclosed chemicals.

Where found:  In addition to being used in perfumes,colognes and deodorants they are included in nearly all cosmetic and personal care products,even on some products marketed as unscented.

Why to avoid:  Studies show that fragrance mixes are associated with allergies, dermatitis, respiratory distress and potential effects on the reproductive system and some are linked to cancer and neurotoxicity.

Sodium Lauryl Sulfate

Sometimes referred to as SLS, it is used in cosmetics as a detergent and to make a product’s bubble and foam.

Where found:  It is common in shampoos, shower gels and facial cleansers, mascara and acne treatment .

Why to avoid:  It is known to be a skin, lung and eye irritant and can have a lasting effect on the epidermis of the skin by damaging the hair follicles.  A major concern about SLS is its potential to interact and combine with other chemicals to form nitrosamine which is a carcinogen.


Widely used as a preservative and anti-microbial chemical in many cosmetics and is used to limit the growth of bacteria and mould.

Where found:  Antibacterial soaps, deodorants, toothpastes, cleansers and hand sanitisers.

Why to avoid:  The chemical, which is classified as a pesticide, can affect the body’s hormone systems especially thyroid hormones.  Widespread use may also contribute to bacterial resistance to anti-microbial agents and making bacteria.


This is a group of chemicals used in hundreds of products to increase the flexibility and softness of plastics.

Where found:  The main phthalates in cosmetics and personal care products are dibutyl phthalate in nail polish, diethyal phthalate in perfumes and lotions and dimethyl phthalate in hairspray.

Why to avoid:  They are known to be endocrine disrupters and have been linked to increase risk of breast cancer, early breast development in girls and reproductive birth defects in males and females.  Unfortunately, it is not disclosed on every product as it is added to fragrances and therefore as part of the “secret formula” is not listed.

Formaldehyde-releasing Preservatives

Chemical compounds that slowly release formaldehyde and are often used as an anti-microbial preservative in cosmetics.

Where found:  Nail polish, nail glue, eyelash glue, hair gel, body wash, baby shampoo and colour cosmetics.

Why to avoid:  These ingredients slowly and continuously release small amounts of formaldehyde that can be inhaled, which the international agency for research on cancer is classified as a human carcinogen.

PEG Compounds

Polyethylene glycol which is a polyether compound.

Where found:  The PEG family of synthetic chemicals function in cosmetic formulations as cleansers, emulsifiers and skin conditioners.

Why to avoid:  Carcinogenic contaminants are the primary concern but there is also evidence of genotoxicity and if used on broken skin can cause irritation and systemic toxicity.  Also PEG functions as a ‘penetration enhancer’ increasing the permeability of the skin to allow greater absorption of the product but this unfortunately includes the absorption of harmful ingredients.

Lead/Heavy metals

Heavy metals such as lead, mercury, cadmium, arsenic and nickel do not have normal physical functions in the body and may have serious negative effects.

Where found:  The main culprits are lipstick, lip gloss and mascara.  It is also found in other colour makeup products including foundation, blush, eye shadow, sunscreens and whitening toothpaste.

Why to avoid:  Lead is a proven neurotoxin linked to learning, language and behavioural problems.  It has also been linked to miscarriage, reduced fertility and delays in puberty onset in girls.


An organic compound that belongs to a class of chemicals called salicylates,which prevent direct skin exposure to the sun’s harmful rays by absorbing ultraviolet light.

Where found:  Sunscreen and skin care products with sun protection.

Why to avoid:  Can impact the body’s hormones in particular estrogens.  It may also irritate and worsen certain skin conditions and skin diseases such as follicultis, eczema, acne and psoriasis.

Placental Extract

Every now and then, beautifiers start bizarre new trends that promise to cure all your skin skin care dilemmas. The use of animal and human placenta is about as wacky as it gets.  Apparently it contains especially high levels of proteins and enzymes including alkaline phosphatase  and collagen – a substance widely used to stimulate skin growth and in some cosmetics to combat wrinkles.

Where found:  In rejuvenating creams to restore and maintain the strength and thickness of ageing skin and in shampoos and conditioners to strengthen hair.

What to avoid:  Studies show that these hormone-altered products are linked to endocrine disruption such as precocious puberty and early sexual maturation and a risk of breast cancer.

(Taken from article by Edel Cassidy)

In Dun Laoghaire Pharmacy we try to stock as many natural products as possible free from the above toxic ingredients.  Products such as Moogoo featured in the above image are natural products without the toxic ingredients listed above.