11 Skin-Safe Cosmetic Ingredients, Explained by a Cosmetic Chemist

Cosmetic labels can be confusing, especially for English learners. This guide, based on the experience of a professional cosmetic chemist, breaks down 11 ingredients often labeled as risky and explains why they are usually safe when used as intended. Read on to make informed choices for your skin.

1. Formaldehyde

Formaldehyde is a colorless gas that can be hazardous when inhaled in large amounts. In cosmetics, exposure is minimal, and it is typically present as trace levels or released slowly, which reduces risk. Historically used as a preservative, it has largely been replaced by safer alternatives such as phenoxyethanol, potassium sorbate, and sodium benzoate. Manufacturers often combine several preservatives to ensure product safety.

Even if a trace amount remains in some cleansers, it is usually rinsed away with water during use, leaving little time for potential harm. In everyday skincare, there is little reason for concern.

2. Propylene Glycol

Propylene glycol acts as a solvent to dissolve active ingredients and improve their skin penetration. It also helps retain moisture in formulas. It is widely regarded as safe for skin and is used to soften hair and improve product texture. It is common in medical products and some injectable formulations as well.

3. Synthetic Fragrances

Synthetic fragrances carry similar allergens to natural scents. If you have allergies to certain components, you may react regardless of whether the fragrance is synthetic or natural. In product labels you may see Parfum or Fragrance. The European Union requires listing potential allergens at the end of the ingredient list, such as limonene, linalool, and geraniol. If you have allergies, look for these names on labels.

4. Silicones

Silicones are inert and generally non-irritating; they do not clog pores and do not form a thick film on the skin. They help reduce water loss while still allowing air and water to pass through. Silicones also break down in soil over time. They provide slip and improve texture, and many people with oily skin prefer silicone-based products because they feel lighter than heavy waxes or oils.

5. Surfactants (PAV)

There are many surfactants. Harsh ones like SLS (sodium lauryl sulfate) and SLES (sodium laureth sulfate) are very effective cleansers but can be drying. In recent years, milder surfactants have become more common, though sulfates still appear in some shampoos and cleansing products. Importantly, non-sulfate formulas aren’t automatically gentle, since other strong surfactants (such as ethoxylated oils or isethionates) may be present. Common milder options include cocoglucoside and cocoamidopropyl betaine.

6. Glycerin

Glycerin is an excellent, affordable humectant that draws moisture to the skin surface and helps prevent evaporation. It does not deeply penetrate the skin, but surface hydration is essential for healthy skin function. Modern research shows skin has mechanisms (aquaporins) that help regulate glycerin for hydration, so it remains physiologically compatible and beneficial.

7. Triclosan

Triclosan is an antimicrobial ingredient designed to reduce bacteria. It appeared in some products about a decade ago, but overuse can disrupt the skin’s natural microbial balance. It can be appropriate for certain uses, such as specific hand sanitizers, but should not be overused in ordinary cosmetics.

8. Mineral Oil

Derived from petroleum, mineral oil is not a natural ingredient, but it is very well tolerated and unlikely to cause allergies. It forms a protective barrier that helps seal in moisture, which can be especially helpful for very dry or atopic skin. It is less ideal for very oily skin, but it can be beneficial for those with severely dry skin. It does not create a breathable film; rather, it reduces water loss and supports the skin’s barrier.

9. Albumin

Albumin is an egg-white protein sometimes used in cosmetics. It can provide moisture and a light lifting effect, with a subtle smoothing appearance. It can trigger allergies in people with an egg allergy. Today, many other actives offer similar benefits, such as polysaccharides, mushroom extracts, or seaweed derivatives.

10. Kaolin

Kaolin is a white clay that helps absorb oil and refine the look of pores, making skin appear more matte. However, it can be drying for normal or dry skin, leading to a tight feeling after use. Modern masks often include humectants like glycerin to counteract this effect and improve comfort.

11. Placental Extract

Placental extracts have been marketed for their nutrient-rich profile, but ethical concerns exist since human placenta is not used in cosmetics. Animal-derived placental extracts or synthetic versions are used instead. The synthetic placental extract combines proteins and peptides that may offer moisturizing benefits, but evidence of extraordinary benefits over well-studied actives is limited. If you encounter it, remember there are other proven options with clearer safety data.

Expert opinion

The cosmetic chemist notes that most so-called harmful ingredients are safe at approved concentrations when used correctly. She emphasizes patch testing and selecting products suited to your skin type as essential steps in safe skincare.

Summary

Overall, many ingredients labeled as risky are not a threat in typical cosmetic use. Understanding what each component does helps you choose products that support hydration, cleansing, and barrier protection without unnecessary fear. Always read labels and test new products on a small area first.

Key insight: In everyday skincare, fears about common ingredients fade when you know their purpose, safe limits, and proper use.