Toxic Ingredients to Avoid in Hair and Skin Products

The average person applies between six and twelve personal care products to their body every day. What many people do not realise is that a significant number of commonly used hair and skin products contain ingredients that have been linked to skin irritation, hormonal disruption, and in some cases, longer-term health concerns. This guide identifies the most important ingredients to be aware of and explains why making the switch to cleaner formulations matters.

Parabens

Parabens (methylparaben, ethylparaben, propylparaben, butylparaben) are synthetic preservatives used in a vast range of cosmetics and personal care products. They have been identified as endocrine disruptors — meaning they can interfere with the body’s hormonal signalling — due to their ability to mimic oestrogen in the body. While regulatory bodies maintain they are safe at current use levels, many consumers choose to avoid them, particularly given the cumulative exposure from multiple products used daily.

Synthetic fragrances

The word “fragrance” or “parfum” on an ingredient list can represent a cocktail of hundreds of undisclosed synthetic chemicals, as fragrance formulas are considered trade secrets and do not need to be individually listed. Many fragrance components are known allergens, irritants, and sensitisers. They are the leading cause of allergic contact dermatitis from cosmetic products, and are particularly problematic for those with sensitive scalps or skin.

Sulphates (SLS and SLES)

Sodium lauryl sulphate (SLS) and sodium laureth sulphate (SLES) are foaming agents found in most conventional shampoos and cleansers. They are effective at removing dirt and oil, but they are also highly effective at stripping the scalp and hair of natural oils, disrupting the skin barrier, and causing dryness and irritation with repeated use. For anyone dealing with scalp sensitivity, dryness, or hair loss, eliminating sulphates from the haircare routine is a worthwhile first step.

Mineral oil and petrolatum

Derived from petroleum, mineral oil and petrolatum are inert substances that coat the hair and skin surface without providing any nutritional benefit. They create the impression of moisturisation by trapping existing moisture, but they can also trap bacteria and sebum, potentially contributing to scalp congestion and follicle blockage over time.

Formaldehyde-releasing preservatives

Ingredients such as DMDM hydantoin, imidazolidinyl urea, and quaternium-15 release small amounts of formaldehyde as they break down. Formaldehyde is a known sensitiser and classified as a human carcinogen at higher exposure levels. These preservatives appear across a wide range of hair care products.

The clean alternative

Choosing products with short, transparent, plant-based ingredient lists is the most effective way to reduce your exposure to potentially harmful ingredients. SkinOne’s natural hair and skin range — including ZenGold Hair Growth Oil — is formulated without synthetic preservatives, artificial fragrances, or petroleum derivatives, using only ethically sourced natural ingredients produced in the UK.

Related guide: For a comprehensive overview, read our complete guide: The Ultimate Guide to Natural Ingredients in Hair and Skin Care

Also useful: Clean Beauty in the UK: What It Means and How to Make the Switch — your practical guide to transitioning to cleaner products.