What Harsh Chemicals Should You Actually Avoid in Skincare?

May 14, 2026 Kerrieanne Lischka

A grounded guide to ingredient concerns

The natural skincare world has a noise problem. On one end, some brands label everything "toxic." On the other, conventional beauty companies dismiss all concern as fear-mongering. The truth is more useful than either extreme: some ingredients have legitimate evidence behind the concern, others don't, and it helps to know the difference.

This guide focuses on the ingredients with the strongest evidence base for concern — not everything called a "chemical" (water is a chemical), but specific compounds with documented links to irritation, hormone disruption, or other health effects.

Sulfates: SLS and SLES

Sodium lauryl sulfate (SLS) and sodium laureth sulfate (SLES) are the foaming agents in most shampoos, body washes, and facial cleansers. They're effective at removing oil and dirt — too effective, in fact. They strip the skin's natural lipid barrier, raising pH, reducing the acid mantle's protective function, and leaving skin dry and reactive.

SLS is also a known skin irritant. The FDA classifies it as safe at concentrations used in rinse-off products, but studies have shown that repeated exposure contributes to barrier disruption and increased skin sensitivity over time, particularly for people with eczema, rosacea, or contact dermatitis.

The Environmental Working Group (EWG) rates SLS as a moderate hazard, with specific concerns around skin irritation and contamination risk in SLES formulations.

Synthetic fragrance

"Fragrance" on an ingredient label is not a single ingredient — it's a trade secret loophole that can represent hundreds of undisclosed chemicals, including known allergens, phthalates, and preservatives. It is the number one cause of allergic contact dermatitis from personal care products.

Even products labeled "unscented" can contain fragrance to mask the smell of other ingredients. True fragrance-free products will say "fragrance-free" explicitly.

Ollie Skincare uses essential oils and fragrances that meet or exceed California Proposition 65. Browse our unscented and naturally scented products.

Parabens

Parabens (methylparaben, propylparaben, butylparaben, etc.) are preservatives used in a wide range of personal care products. They're effective at preventing microbial growth — but they're also known endocrine disruptors. Parabens mimic estrogen in the body by binding to estrogen receptors, and they've been found in breast tissue samples.

The evidence linking parabens to breast cancer is not conclusive, but the precautionary principle is reasonable: there are safer preservative alternatives, and many brands have moved away from parabens entirely. Ollie Skincare does not use parabens.

Methylisothiazolinone (MI) and methylchloroisothiazolinone (MCI)

These preservatives are among the most common causes of allergic contact dermatitis identified in dermatology clinics. In Europe, MI was banned from rinse-off products in 2014 and its permitted concentration in leave-on products was drastically reduced after a wave of reported reactions. In the US, it remains permitted but increasingly avoided by dermatologists and brands focused on sensitive skin.

If you've ever had a mysterious skin reaction you couldn't trace to a specific product, MI or MCI may have been the culprit. Check your body wash, shampoo, and baby wipes.

Phthalates

Phthalates are plasticizers used to make fragrances last longer and to soften plastic packaging. They're often unlisted on labels because they fall under the "fragrance" umbrella. Like parabens, phthalates are endocrine disruptors with documented effects on hormone regulation, particularly in children and during pregnancy.

The safest way to minimize phthalate exposure from skincare is to avoid products with "fragrance" or "parfum" on the label and choose brands that use glass, tin, or certified phthalate-free plastic packaging.

Retinol — a nuanced case

Retinol isn't a toxin, but it deserves a nuanced mention. It's a powerful vitamin A derivative that increases cell turnover and stimulates collagen — genuinely effective for aging. But it also causes significant irritation during the adjustment period (redness, peeling, dryness), makes skin more sensitive to UV, and is contraindicated during pregnancy.

For people with sensitive or reactive skin, the irritation cost of retinol often outweighs the benefit — especially when gentler alternatives like bakuchiol and vitamin A-rich plant oils can support cell turnover without the sensitivity.

At Ollie, we choose not to use retinol. Instead, our formulas use plant-derived vitamin A sources and rosehip oil — which contains trans-retinoic acid naturally — to support healthy skin renewal without the irritation. See also:

What Ollie Skincare avoids — and why

Every Ollie product is made without:

Synthetic fragrance and artificial dyes
Parabens, MI, MCI, and other synthetic preservatives
Sulfates (SLS, SLES)
Phthalates
Retinol and synthetic AHAs/BHAs
Unnecessary fillers and stabilizers

Our ingredient philosophy is simple: if an ingredient doesn't do something helpful for your skin, it doesn't belong in the formula. Read more about our approach to skincare.

How to read a skincare label

Ingredients are listed in descending order by concentration. The first five ingredients make up the bulk of any formula — those are the ones that matter most. Anything listed after fragrance or preservatives is typically present in trace amounts.

Look for:

Short ingredient lists — fewer ingredients mean fewer risks and easier troubleshooting
Recognizable names — "goat milk," "shea butter," "sunflower oil" are clearer than "caprylic/capric triglycerides"
No "fragrance" or "parfum" on the list
No -paraben suffixes, no isothiazolinone variants, no PEG compounds