What to look for on a label: methylparaben, ethylparaben, propylparaben, butylparaben, heptylparaben, isobutylparaben, isopropylparaben and benzylparaben.

Parabens are a family of synthetic esters of p-hydroxybenzoic acid that share similar molecular structures and are widely used as preservatives. They are found in a wide array of products, from lotions, to body washes and shampoos.

There are several different parabens. You can find them listed as: methylparaben, ethylparaben, propylparaben, butylparaben, heptylparaben, isobutylparaben, isopropylparaben and benzylparaben.

Paraben compounds, the most common being methylparaben, propylparaben and butylparaben, have been found to affect oestrogen levels, potentially impacting female reproductive health (Gao et al, 2016).

This is further supported by a new study by Geer et al (2016), which found an association between antimicrobials and adverse birth outcomes in neonates. These findings are also consistent with animal data resulting in developmental and reproductive toxicity.

There are many much safer preservatives out there; you will usually find them in natural or organic products.

What to look for on a label: sodium laureth sulphate, sodium lauryl sulphate.

Sodium lauryl sulphate was introduced globally more than 60 years ago as emulsifier or detergent. Alone, or accompanied by other surfactants, it is found in many cosmetic products, especially in shampoos and body washes.

Studies on skin irritation of surfactants show that irritation is dependent on the structure of the sulphate. SLS is an anionic detergent, which tends to be more irritating to the skin and eyes in comparison to amphoteric and non-ionic detergents (L. Rhein, 2007).

Their ability to remove stratum corneum lipids means they penetrate the skin deeper into the viable layers and can cause immune reactions (Lémery et al, 2015).

SLS is one of the cheapest and strongest surfactants used in skin care; it is also one of the most irritating. Trying to make it less irritating, chemists created SLeS, which is produced through process of ethoxylation. This resulted in a surfactant that is indeed less irritating to the skin, but is regularly contaminated with 1,4-dioxane, a carcinogen byproduct of the chemical reaction.

In addition, SLS and SLeS are also known to elicit skin reactions such as irritant contact dermatitis or may cause inflammation. Though emulsions are often used to treat inflammatory skin disorders such as eczema, emulsions may also cause skin disorders because of the presence of surfactants added as stabilisers (Bárány et al, 2000).

What to look for on a label: ingredient names starting with PEG eg PEG-100 Stearate or Polysorbate, eg Polysorbate 20.

Polyethylene glycols are petroleum-based ingredients and are often used in creams in particular, as a moisturizing agent.

They have a penetration-enhancing effect, which is important to remember for several reasons:

• PEGs make it easier for other undesirable ingredients in your skincare products to penetrate deep into your skin.
• PEGs have the potential to disrupt the skin’s natural moisture balance, thus altering the surface tension of the skin.
• PEGs often come contaminated with toxic impurities. Examples of these impurities are ethylene oxide and 1,4-dioxane. Studies have shown exposure to high concentrations of 1,4-dioxane may cause eye, skin, and respiratory irritation, nervous system effects, and liver and kidney toxicity (Stickney and Carlson-Lynch, 2014).

Although ethylene oxide has exhibited a low carcinogenic potency in animal models, epidemiological studies have not conclusively linked exposures to ethylene oxide with carcinogenic outcomes in humans (Parod, 2014). Information on PEG toxicity is limited and contradictory, but they should be avoided to ensure safety.

You can easily find PEGs among the listed ingredients (eg PEG-100 Stearate, PEG-40 Hydrogenated Castor Oil), but keep in mind that PEGs are also hidden under less obvious names, most typically ‘polysorbates’. These are a group of nonionic surfactants that help to hold water and oil together in creams, and also help dissolve other ingredients in water. They are used in a variety of products including skin fresheners, skin care products, skin cleansing products, makeup bases and foundations, shampoos and fragrance powders. Their name contains the word ‘polysorbate’ plus a number, which reveals how many PEG molecules it contains, eg Polysorbate 20, Polysorbate 60, Polysorbate 80, etc.

Nowadays PEGs as solubilizers are replaced with polyglyceryl-ingredients, which are permitted in natural cosmetics.

What to look for on a label: paraffinum liquidum, paraffinum, cera microcristallina, petrolatum, mineral oil or paraffin waxes.

Mineral oil is a byproduct of refining crude oil to make gasoline and other petroleum products. It is very inexpensive, has a long shelf life and it is also quite an effective emollient. Due to these advantages to the cosmetic industry it is very widely used in skincare products for example in body lotions, facial creams and lipsticks or lip balms.

Even though you can find many myths about it on the internet usually stating mineral oil clogs pores or doesn’t let the skin breathe, they are not true. The real problem with mineral oil is slightly more complicated. Mineral oils are mixture of complex hydrocarbons comprised of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH). It has been proven that if MOSH are absorbed the body, they are stored in various organs and may cause damage to the liver and lymph nodes. MOAH are potentially carcinogenic and are prohibited in food substances by the European Food Safety Authority. Cosmetic-grade mineral oils are supposed to be highly purified and have all of the MOAH removed from them, so they only contain MOSH. Sadly, tests have shown that that’s not always the case. This issue is only problematic in lip care products, because some of the products gets ingested through the mouth. Otherwise, mineral oils are not absorbed by the skin (Lorenzini et al., 2010).

You can find mineral oils under several different names:  paraffinum liquidum, paraffinum, cera microcristallina, petrolatum, mineral oil or paraffin waxes.

There are much better alternatives out there – vegetable carrier oils are great emollients, they contain beneficial fatty acids, vitamins and antioxidants, plus they are completely safe to be used on the lips as well!

What to look for on a label: various ingredients including beeswax, cera alba, cera bellina, lanolin, lanolin alcohol, lanolin wax, lanolin cera, laneth-.

Animal-derived products aren’t dangerous, but they are something you might want to avoid if you are living a vegan lifestyle or you are concerned about animal welfare.

One of the most commonly used animal-derived ingredient in skincare products is definitely beeswax. It is produced by bees and it works as a protective ingredient in creams and as hardening substance in all kinds of balms. It has many benefits for the skin, but research shows that it can contain residues of pesticides (Ravoet et al., 2015), plus it is known for causing allergic reactions. You can find certified organic beeswax on the market or you can choose a product with a plant-derived wax instead (candelilla wax, soy wax, carnauba wax).

When looking for beeswax, you can find it under the names: beeswax, cera alba and cera bellina.

Another common ingredient is lanolin. It is a wool wax, secreted by the sebaceous glands of wool-bearing animals, typically sheep. Because it resembles the skin’s own sebum it is a popular ingredient that helps to moisturize the skin. Similar to beeswax, it does have many beneficial properties, but it is also known for being contaminated with traces of pesticides, especially insecticides used to protect sheep from pests (Jover and Bayona, 2002). There are vegetable alternatives available, they are similarly effective in moisturizing and nourishing. Typically they are a mix of carrier oils or butters with glyceryl rosinate.

Lanolin is listed under a number of names: lanolin, lanolin alcohol, lanolin wax, lanolin cera, laneth-x (x being a number; this is ethoxylated lanolin).

What to look for on a label: fragrance, parfum.

We all love the appealing scent of cosmetic products, don’t we? Unfortunately, fragrances are only listed as ‘fragrance’ or ‘parfum’ on the label, but they are a complex mixture of many chemicals, which are not disclosed. This has raised some concerns as there have been some reported side-effects of these substances related to skin sensitivity, rashes, dermatitis, coughing, asthma attacks, migraine, etc (De Groot and Frosch, 1997, Bickers, et al., 2003).

To enjoy a lovely odour during your skincare routine, choose products that are lightly scented with natural and gentle essential oils.

It can be difficult to tell if a product contains synthetic fragrance or natural essential oils as both can be listed as fragrance or parfum on a label (companies are not required to declare which essential oils they use if they don’t want to). However, companies usually put an asterisk sign to the word parfum and write something like “from natural essential oils” in the notes under the INCI list.

Many fragrances, natural and synthetic alike, contain allergens that are legally required to be listed at the end of a ingredient list. Typical examples are linalool, limonene, citronellol, benzyl benzoate, benzyl alcohol, etc. If they come from essential oils, they almost always have an asterisk sign next to them and a note “*from natural essential oils” is present under the ingredients list.

What to look for on a label: imidazolidinyl urea, DMDM hydantoin, diazolidinyl urea, methenamine, quarternium-15.

Formaldehyde-releasing preservatives (FRPs) are used in many products to help prevent microbial contamination. Their formaldehyde-releasing ability makes them a potential allergen and toxicant in humans. Formaldehyde in cosmetics is widely understood to cause allergic skin reactions and rashes in some people (Flyvholm MA and Menne T, 1992; Boyvat A, 2005; Prat et al 2004).

When checking for FRPs, look for ingredients called Imidazolidinyl urea, DMDM hydantoin, diazolidinyl urea, methenamine, and quarternium-15.

There are more and more safer alternatives for cosmetic preservation available, they are usually present in certified organic products, where FRPs are forbidden.

What to look for on a label: various ingredients including Dimethicone, Methicone, Trimethicone, Cyclomethicone, Amodimethicone, Trimethylsilylamodimethicone, Cyclopentasiloxane, Dimethiconol.

Silicones are synthetically made polymers with structural backbone made of silicon and oxygen atoms. They have a unique, powdery dry skin feeling with an amazing slip, that’s the reason they are the main ingredients in makeup primers and foundations. They can also work as occlusives in moisturizers and body butters (where they lessen the greasy feeling on the skin). Because of the dry skin feel they are the main ingredient of dry oils for body care. SIlicones are popular in hair care products as well, they are conditioning and detangling, plus they provide shine, which is why they are basic ingredient of hair oils.

Maybe you’ve heard silicones ‘suffocate skin’ and prevent other ingredients from penetrating into the skin. That is not true. However, besides making the skin feel silky smooth, they do not have any other benefits for it (like rejuvenating antioxidants and vitamins) – they make the skin look healthier and nicer, but that is just a temporary effect, they do not actually nourish the skin. They can also cause product build-up on your scalp, so if you use them very frequently, a clarifying shampoo is a must.

Another reason you might want to avoid silicones is the fact that since they are not biodegradable, they are a problem for the environment due to bioaccumulation.

There are several kinds of them, but you can recognize their names, which are ending in “-cone” or “-siloxane”: Dimethicone, Methicone, Trimethicone, Cyclomethicone, Amodimethicone, Trimethylsilylamodimethicone, Cyclopentasiloxane, Dimethiconol.