Deodorant

A fast-evaporating solvent used to carry actives and give toners a light, "clean" feel; at the concentrations used in classic astringents it can be genuinely drying or irritating with repeated use, especially on dry or compromised skin, though it is not inherently toxic and is a normal, well-studied cosmetic ingredient.

The base most products are built on. It carries the other ingredients and has no safety concern.

A plant extract used for mild astringent and soothing effects. Evidence for its benefits comes mostly from traditional use and small studies rather than large trials, and the tannins it contains can be mildly irritating for some people, particularly in older distilled formulas that retain trace alcohol.

A synthetic surfactant and emulsifier that blends oils and water in cosmetics and has been used safely for decades in cosmetics and pharmaceuticals. Published safety literature is extensive and reassuring at cosmetic levels.

A humectant that draws water into the skin. One of the best-studied, best-tolerated ingredients in personal care.

A buffering agent used in small amounts to maintain or adjust the pH of formulas to keep them skin-friendly. It is not added as an active ingredient but to keep the product at a safe and stable pH level.

Used in tiny amounts to set a product to skin-friendly pH. No concern at those levels.

Lavender essential oil naturally contains linalool, geraniol, and coumarin, several of the recognized fragrance allergen constituents, so it can trigger contact reactions in fragrance-sensitive users even though it is a "natural" ingredient. It is not a general hazard for most people, but those with a known fragrance allergy should treat it like any other essential oil.

An essential oil with a distinctive cooling scent, eucalyptus contains recognized fragrance allergen constituents and can trigger contact reactions in fragrance-sensitive individuals. People with known sensitivities to essential oils or fragrance should avoid it or use with caution.

Tea tree oil is used for its antimicrobial reputation in blemish-focused products, but it is a genuine, well-documented contact sensitizer, and its allergy potential rises sharply once the oil has oxidized from air exposure. Fresh, well-preserved, low-concentration formulations are much lower risk than old or improperly stored oil.

A floral fragrance component and one of the EU-labelled fragrance allergens. Usually fine, worth watching if you react to scented products.

A rose-scented fragrance ingredient found naturally in geranium and rose oil. It is one of the 26 fragrance allergens the EU requires to be labeled by name because a minority of people develop skin sensitization to it, though most users tolerate it without issue.

A floral, rose-like fragrance compound found in many essential oils. It is one of the 26 EU-designated fragrance allergens, meaning a documented minority of people can develop contact sensitization, so brands must disclose it above set thresholds.

A spicy, clove-derived fragrance and flavor compound. It is one of the 26 EU-designated fragrance allergens because it can trigger contact allergy in sensitized individuals, though CIR review found it safe as typically used in cosmetics.

A natural fragrance component found in citrus oils and lemongrass, giving a lemony scent. It is a named EU fragrance allergen that can oxidize into potent contact allergens over time; people with known fragrance sensitivities may react.

Farnesol is a natural fragrance and mild antimicrobial found in essential oils, and it is one of the EU-listed allergens requiring label disclosure. It has moderate documented sensitization potential, more so with repeated or prolonged exposure.

A citrus-scented fragrance component. Fine for most, but it oxidizes over time into a known contact allergen, so it must be labelled in the EU.