Ingredients

Bronopol — a preservative that can release formaldehyde and form nitrosamines.

Also written Bronopol

A preservative and solvent. Also a listed fragrance allergen, though reactions at preservative levels are uncommon.

One of five parabens banned from cosmetics in the EU since 2014 because their safety couldn't be shown.

A longer-chain paraben. Like propylparaben, the EU has lowered its permitted concentration and bans it in leave-on products for the nappy area of young children, over possible hormone effects.

A humectant that also boosts preservatives. Well tolerated.

A preservative permitted up to 0.3% in the EU. Occasionally irritating.

A formaldehyde-releasing preservative and a known cause of contact allergy.

A preservative that works by slowly releasing formaldehyde, a known sensitizer and carcinogen. Products containing releasers must carry a warning in the EU when formaldehyde levels are high.

Boosts preservatives (often paired with phenoxyethanol) and conditions skin. Occasional allergen.

A short-chain paraben. Like methylparaben, considered safe at permitted levels by EU scientific committees, and among the least allergenic preservatives.

A formaldehyde-releasing preservative and a known cause of contact allergy.

One of five parabens banned from cosmetics in the EU since 2014 because their safety couldn't be shown.

One of five parabens banned from cosmetics in the EU since 2014 because their safety couldn't be shown.

A strong sensitizer, usually paired with MIT. Allowed only in rinse-off products in the EU.

Also written Kathon CG, MCI, Methylchloroisothiazolinone/Methylisothiazolinone

A preservative behind an epidemic of contact allergy in the 2010s. Banned in leave-on products in the EU; allowed only at low levels in rinse-off.

Also written MI, MIT

A short-chain paraben. Methyl- and ethylparaben are considered safe at permitted levels by EU scientific committees and are among the least allergenic preservatives.

One of five parabens banned from cosmetics in the EU since 2014 because their safety couldn't be shown.

The most common preservative today. Safe at the permitted 1%; rarely irritating.

One of five parabens banned from cosmetics in the EU since 2014 because their safety couldn't be shown.

A food-grade preservative against mould and yeast.

A longer-chain paraben. The EU has lowered its permitted concentration and bans it in leave-on products for the nappy area of young children, over possible hormone effects.

A formaldehyde-releasing preservative, banned in cosmetics in the EU.

A food-grade preservative that works in acidic formulas.

An antibacterial restricted in the EU and removed from US antibacterial soaps, over hormone effects, antibiotic resistance and environmental harm.