Into The Night

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

A coconut-derived amphoteric surfactant used to boost foam and mildness in cleansers and shampoos. CIR has reviewed it as safe as used, but it is one of the more established contact-allergy triggers in personal care, usually traced to manufacturing impurities such as amidoamine and dimethylaminopropylamine (DMAPA) rather than the betaine itself. People with a history of eyelid or scalp dermatitis are more likely to react.

A gentle amino acid-based surfactant derived from coconut oil, used as a primary cleanser in many sulfate-free shampoos and body washes. It is well tolerated and designed to reduce irritation common to harsher sulfonated surfactants.

An undisclosed scent blend that can contain dozens of components. The single most common cause of cosmetic contact allergy, and the blend is not itemized, so you cannot see what is in it.

A sulfate-free, amino acid-derived surfactant with a mild profile often used in gentle body washes and shampoos. It is well tolerated and formulated to provide effective cleansing with reduced risk of irritation compared to traditional sulfate surfactants.

A mild, coconut-derived cleansing surfactant widely used in syndet bars and creamy body washes because it foams without stripping the skin barrier as hard as sulfates. Long track record with no meaningful irritation signal at wash-off use levels.

A plant-derived water or extract used mainly as a soothing humectant filler. Evidence for dramatic skin benefits beyond mild hydration and soothing is limited, but it is well tolerated by most people.

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

A gentle, PEG-based emulsifier and solubilizer that blends sugar and fatty acid derivatives for stable formula incorporation. PEG compounds in cosmetics are non-penetrating and rinse cleanly from the skin.

A widely used preservative, safe at the legal limit of 1% or less. Often the "paraben-free" replacement.

A preservative and antioxidant that helps prevent microbial growth and oxidative degradation in formulas. Published assessments support its use at cosmetic levels.

A soothing humectant that helps skin and hair look conditioned. Very well tolerated.

Tetrasodium EDTA is a chelating agent that binds trace metal ions to keep formulas stable and help preservatives work better. It has circulated online as a supposed "toxic" additive, but decades of safety review support its use at cosmetic concentrations.

A silicone emulsifier combining polyethylene glycol and dimethicone to help blend water and oil phases in serums and primers. Limited but consistent data support its safety in cosmetic formulations.

A corn-derived solvent and humectant that has largely replaced propylene glycol in "clean" formulas; CIR reviewed the alkane diol group and found use concentrations up to about 40 percent in leave-on products like deodorant sticks with no meaningful irritation signal.

A widely used emulsifier and solubilizer that has been in cosmetics and pharmaceuticals for decades. The CIR has assessed it as safe with no known concerns at typical cosmetic concentrations. As with any surfactant, some people with very sensitive skin may experience mild irritation.

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

This small glycol is used to thin out formulas and help preservatives work better, similar in role to propylene glycol and butylene glycol already in wide use. Industry and EU safety reviewers have set purity and concentration conditions for its use rather than restricting it outright, and no consumer-relevant hazard has been established at typical cosmetic levels.

Caprylyl glycol is a plant-derived humectant that also has mild antimicrobial properties, so it is commonly paired with other preservatives to allow lower overall preservative levels. Available data do not point to meaningful irritation or sensitization concerns at typical use levels.

A small humectant and solvent molecule that helps other ingredients dissolve and helps skin hold water. It is one of the most studied cosmetic ingredients and is considered safe at the concentrations used in personal care products.

A small-dose synthetic antioxidant that prevents oils and fragrance in a formula from oxidizing. Not shown to pose a toxicological risk at the levels used in cosmetics.

A polypropylene glycol-based surfactant and emulsifier used to stabilize cosmetic formulas. Safety assessments indicate it is well-tolerated when used at typical cosmetic concentrations.

A PEG ester derived from caprylic and capric fatty acids, used as an emulsifier and solvent in skincare formulations. PEG-modified esters are assessed as safe by the CIR in cosmetics when used at typical concentrations.

A polyethylene glycol ester of hydrogenated castor oil, widely used as an emulsifier and solvent in rinse-off and leave-on cosmetics. PEG-modified ingredients are graded as safe in cosmetics by the CIR when formulated at typical use levels.

A widely used UVB chemical filter with a long safety record at US-approved concentrations. Some lab and animal studies have raised questions about hormone activity and coral reef impact, which is why a few jurisdictions cap or restrict it, but human-relevant risk at labeled use levels is considered low by regulators.

A mild UVB chemical filter usually used to help dissolve and stabilize other sunscreen actives. It has a long OTC history at US-approved levels with a low rate of reported irritation.

A widely used organic UV-A filter in sunscreens. It can lose effectiveness in sunlight unless paired with photostabilizers, but safety reviews have not found it to pose a meaningful health hazard at approved use levels.

A strong alkali used in tiny amounts to adjust the pH of cosmetics to safe, skin-friendly levels. At the pH found in finished products, sodium hydroxide is neutralized and well tolerated.

Benzyl salicylate is a fragrance fixative that also absorbs some UV light. It is on the EU allergen disclosure list, but the evidence suggests it sensitizes fewer people than most other listed fragrance allergens.

Hydroxycitronellal is a lily-of-the-valley scented fragrance ingredient on the EU allergen disclosure list. It has well-documented sensitizing potential in patch-test studies, so it is worth checking the label if you have known fragrance sensitivities.

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

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.

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 sweet, hay-like fragrance ingredient naturally found in tonka bean and lavender. It is one of the 26 EU-designated fragrance allergens and is also subject to an EU maximum concentration limit in finished cosmetic products.

An FDA-approved synthetic colorant commonly used in cosmetics and personal care products. A small proportion of individuals report sensitivity or allergic reactions, particularly those with existing dye sensitivities. Remains safe at approved cosmetic concentrations.

An FDA-approved synthetic colorant used in cosmetics to create red shades. Dye sensitivity can occur in sensitive individuals, though it is uncommon. Generally well tolerated at regulated cosmetic levels.