5 Ingredients to Avoid in your Skincare Products

1. Propylene glycol

A clear, odorless, non-volatile, oily liquid with solvent properties similar to alcohol. It acts as a carrier for active ingredients and penetration enhancer. It's also hygroscopic, keeping the surface of creams moist and preventing the formation of a 'skin.' Like alcohol, it can kill microorganisms, thus contributing to product preservation. 

Why avoid it? It can cause Chemical Irritation, dissolving natural skin lipids and disrupting the moisture barrier. It can also cause Allergic Contact Dermatitis (ACD), especially on sensitive or compromised skin.

2. Fragrance

Linalool is a widely used fragrance ingredient. A source of a pleasant floral, spicy scent. It's a terpene alcohol, obtained from both plants and insects (such as termites). Used as a fragrance ingredient in 60-80% of scented cosmetics.

Limonene is also widely used, providing a citrus-like scent. Like Linalool, it's a terpene, but structurally different in that it contains a ring of carbon atoms.

The most common cause of ACD from skin care products. Linalool oxides cause ACD in 5-7% of the population. Limonene and its oxides are also potent sensitizers in more than 3% of the population.

3. Kathon (Methylchloroisothiazolinone or methylisothiazolinone)

The brand name of a mixture of two chemicals known as isothiazolinones. It is shown on a cosmetic label as: Methylchloroisothiazolinone or methylisothiazolinone. It's a powerful preservative that kills bacteria, mold and yeast. It's a cytotoxic allergen, voted "2013 Contact Allergen of the Year" by the American Contact Dermatitis Society. Avoid it at all costs.

4. Parabens

Esters (methyl, ethyl, propyl, etc.) of parahydroxybenzoic acid, a phenolic compound that kills microorganisms. Parabens are low cost, highly effective preservatives for cosmetic products.

You should avoid them because they can cause ACD in patients with barrier compromised skin. There is also evidence that Methylparaben can be converted into a toxic reactive oxygen species on exposure to UV light, leading to skin aging.

5. Sodium lauryl sulfate