Cosmetic Ingredient Glossary

1

1,4-Dioxane We avoid

Also listed as: dioxane

A contaminant, not an ingredient, so it never appears on a label. It can form in trace amounts when ingredients are ethoxylated, as with PEGs, polysorbates and sodium laureth sulfate. IARC lists it as possibly carcinogenic to humans, and New York now caps it at 1 part per million in cosmetics. Vacuum stripping during manufacturing can reduce levels. Read the full guide

A

Acrylates Copolymer Use with care

Also listed as: acrylates/C10-30 alkyl acrylate crosspolymer, acrylates crosspolymer

A synthetic film forming polymer used in mascara, nail polish, hair gels and long wear makeup to hold shape and resist water. Safety panels consider it low risk for skin, and irritation is uncommon. The bigger question is environmental: it is one of the liquid or soluble polymers that do not break down readily once they wash down the drain. Read the full guide

Activated Charcoal Natural

Also listed as: charcoal powder, activated carbon, charcoal

A highly porous form of carbon, usually made from coconut shells or wood, used in soaps, masks and deodorants. Its large surface area helps absorb oil and odor. Claims that it pulls toxins out of the skin are not well supported. It is gentle for most people, though peel off charcoal masks can be harsh on skin. Read the full guide

Aluminum Chlorohydrate Use with care

Also listed as: ACH, aluminum chlorohydrex

The most common active ingredient in antiperspirants. It forms temporary plugs in sweat ducts to reduce wetness, and the FDA regulates it as an over the counter drug. Research has not established a link to breast cancer or Alzheimer's disease, though some people prefer to skip it. It can sting freshly shaved or irritated skin. Read the full guide

Aluminum Zirconium Tetrachlorohydrex Gly Use with care

Also listed as: aluminum zirconium trichlorohydrex gly, aluminum zirconium

A stronger antiperspirant salt found in many clinical strength sticks and gels. Like other aluminum salts, it reduces sweat by temporarily blocking sweat ducts, and the FDA regulates it as a drug active. The FDA does not allow it in aerosol sprays. Current evidence does not show it causes disease, but it can irritate sensitive underarms. Read the full guide

Ammonium Lauryl Sulfate We avoid

Also listed as: ALS

A strong foaming surfactant closely related to SLS, used in shampoos, body washes and bubble baths. It cleans well but can strip natural oils and leave sensitive skin or color treated hair feeling dry. Safety reviewers consider it acceptable in rinse off products at typical levels, where contact time is short. Read the full guide

Argan Oil Natural

Also listed as: argania spinosa kernel oil, Moroccan oil

A golden oil pressed from the kernels of the argan tree, native to Morocco. It is rich in oleic and linoleic fatty acids and vitamin E, and it absorbs readily. It helps smooth frizz, adds shine to hair and softens dry skin. Cosmetic argan oil is cold pressed from raw kernels, while culinary oil comes from roasted kernels. Read the full guide

Arrowroot Powder Natural

Also listed as: maranta arundinacea root powder, arrowroot starch

A fine, silky starch from the roots of the arrowroot plant, used in natural deodorants, body powders and dry shampoos. It absorbs moisture and helps underarms feel drier without blocking sweat ducts. It is a popular talc free alternative. It is gentle for most people and rarely irritates skin. Read the full guide

Avobenzone Use with care

Also listed as: butyl methoxydibenzoylmethane

A chemical UVA filter used in most US chemical sunscreens. It breaks down in sunlight, so formulators often pair it with octocrylene to stabilize it. FDA studies found it absorbs into the bloodstream, which does not mean it is harmful, and the agency has asked for more safety data. It occasionally causes allergic reactions. Read the full guide

Avocado Oil Natural

Also listed as: persea gratissima oil, persea americana oil

A rich oil pressed from avocado fruit, high in oleic acid with vitamin E and plant sterols. It softens dry skin, adds slip and conditioning to hair products, and gives soap a creamy, mild lather. Unrefined avocado oil is green and earthy smelling. It suits dry and mature skin well and is rarely irritating. Read the full guide

B

Beeswax Natural

Also listed as: cera alba, cera flava, yellow beeswax

A natural wax made by honeybees, used in balms, lip balms, salves and mineral sunscreens. It forms a breathable protective layer that helps skin hold onto moisture and gives products a firm texture. Allergy is uncommon but possible, especially for people sensitive to bee products or propolis. Candelilla wax is a common vegan swap. Read the full guide

Bentonite Clay Natural

Also listed as: bentonite, montmorillonite, sodium bentonite, calcium bentonite

A clay formed from weathered volcanic ash, used in face masks, natural deodorants and bath products. It absorbs excess oil and moisture and swells when wet. Clays can contain trace heavy metals, and the FDA has warned about lead in some bentonite products sold for ingestion, so cosmetic grade, tested clay matters. Read the full guide

Benzalkonium Chloride Use with care

Also listed as: BAC, BZK, alkyldimethylbenzylammonium chloride

A quaternary ammonium compound (quat) used as an antimicrobial in alcohol free hand sanitizers, wipes, eye drops and some preservative systems. It is effective at low levels, but it can irritate skin and is a known contact allergen for some people. The FDA has asked for more data before finalizing its status in consumer hand antiseptics. Read the full guide

Benzene We avoid

A solvent that IARC classifies as a known human carcinogen. It is not an intentional cosmetic ingredient, but since 2021 it has been found as a contaminant in some aerosol dry shampoos, sprays and sunscreens, likely from propellants, which led to voluntary recalls. It will not appear on a label, so choosing non aerosol formats is one way to limit exposure. Read the full guide

Bergamot Oil Use with care

Also listed as: citrus aurantium bergamia peel oil, citrus bergamia peel oil, bergamot essential oil

An essential oil pressed from the peel of bergamot oranges, with a bright citrus and floral scent. Cold pressed bergamot contains bergapten, which can cause phototoxic burns or dark patches when skin is exposed to sunlight. Bergapten free (FCF) bergamot avoids this. Like all essential oils, it should be well diluted. Read the full guide

BHA We avoid

Also listed as: butylated hydroxyanisole, E320

A synthetic antioxidant that keeps oils and fragrances from going rancid in lipsticks, moisturizers and makeup. IARC lists it as possibly carcinogenic to humans, and California includes it on its Proposition 65 list. It is still permitted in cosmetics. Do not confuse it with beta hydroxy acid (salicylic acid), which shares the same initials. Read the full guide

BHT Use with care

Also listed as: butylated hydroxytoluene, E321

A synthetic antioxidant related to BHA, used in small amounts to keep oils and fragrances fresh. EU scientific reviewers consider it safe at the low concentrations used in cosmetics, and it is not classified as a carcinogen. Some shoppers still avoid it because of mixed animal data. Vitamin E (tocopherol) is a common natural alternative. Read the full guide

Black Seed Oil Natural

Also listed as: nigella sativa seed oil, black cumin seed oil, kalonji oil

An oil pressed from the seeds of nigella sativa, used for centuries in the Middle East and South Asia. It contains thymoquinone and fatty acids that help condition the scalp and hair. It has a strong, peppery scent and can irritate some people, so it is usually diluted with other oils and patch tested first. Read the full guide

Bronopol We avoid

Also listed as: 2-bromo-2-nitropropane-1,3-diol

A preservative that can slowly release small amounts of formaldehyde. When combined with amines such as DEA or TEA it can also help form nitrosamines inside a product. The EU allows it at up to 0.1 percent and restricts its use where nitrosamines could form. It appears mainly in some shampoos, cleansers and wipes. Read the full guide

Butylene Glycol Use with care

Also listed as: 1,3-butanediol

A humectant and solvent related to propylene glycol, common in serums, toners and sheet masks. It helps draw moisture into the skin and helps other ingredients spread evenly. It is generally considered gentler than propylene glycol, and irritation or allergy is uncommon. People with very reactive skin may still want to patch test. Read the full guide

Butylparaben We avoid

Also listed as: butyl paraben, butyl 4-hydroxybenzoate

A longer chain paraben preservative that shows more estrogen-like activity in lab studies than methyl or ethylparaben. The EU limits butyl and propylparaben combined to 0.14 percent and bans them in leave on products for the diaper area of young children. The FDA has not found that parabens at typical levels harm health. Read the full guide

C

Calomel We avoid

Also listed as: mercurous chloride, mercury, mercuric chloride, ammoniated mercury

A mercury compound that turns up in some illegally sold skin lightening and anti blemish creams, usually imported or bought online. Mercury can damage the kidneys and nervous system and can affect other people in the household. The FDA allows mercury only as a trace contaminant or tiny preservative amount in some eye products, so watch for it on labels. Read the full guide

Carrot Seed Oil Natural

Also listed as: daucus carota sativa seed oil, carrot seed essential oil

An essential oil distilled from the seeds of wild carrot (Queen Anne's lace), with an earthy, woody scent. It is added to facial products and mineral sunblocks for scent and skin conditioning. Contrary to online claims, carrot seed oil does not provide meaningful sun protection on its own. It should be diluted like other essential oils. Read the full guide

Castor Oil Natural

Also listed as: ricinus communis seed oil, ricinus communis oil

A thick oil pressed from castor beans, made mostly of ricinoleic acid. It adds shine and gloss to lip balms, boosts lather in soap and conditions hair and lashes. Claims that it grows hair are not supported by solid research. Its thickness makes it best blended with lighter oils, and it occasionally irritates sensitive skin. Read the full guide

Ceteareth Use with care

Also listed as: ceteareth-20, ceteareth-25, ceteareth-12

A family of ethoxylated emulsifiers made from cetearyl alcohol, used to blend oil and water in lotions, creams and conditioners. Safety panels consider them safe as used, though they advise care on damaged skin. Because they are ethoxylated they may carry traces of 1,4-dioxane, and the number after the name reflects the length of the ethylene oxide chain. Read the full guide

CI 77491 Use with care

Also listed as: red iron oxide, iron oxides, CI 77492, CI 77499

The color index number for red iron oxide, a mineral pigment used in foundations, blushes, lipsticks and tinted sunscreens. Iron oxides are generally considered low concern and are allowed even near the eyes. Most cosmetic iron oxides are made in a lab for purity, and the main quality issue is keeping heavy metal impurities within limits. Read the full guide

Citronella Oil Use with care

Also listed as: cymbopogon nardus oil, cymbopogon winterianus oil

An essential oil from citronella grass, used in natural insect repellents, candles and soaps. The EPA has registered it as a repellent ingredient, though protection tends to be shorter than with DEET, so reapplication helps. It contains compounds that can irritate or sensitize skin, so it should be diluted and patch tested. Read the full guide

Coal Tar We avoid

Also listed as: coal tar solution, pix carbonis, coal tar dyes

A byproduct of coal processing used as an active ingredient in some dandruff and psoriasis shampoos, which the FDA regulates as drugs. IARC classifies coal tar as a human carcinogen, mainly based on workplace exposure, and the EU bans it in cosmetics. "Coal tar dyes" is an older term for synthetic colors, which today are mostly made from petroleum. Read the full guide

Cocamide DEA We avoid

Also listed as: cocamide diethanolamine, coconut diethanolamide, lauramide DEA

A foam booster and thickener made by reacting coconut fatty acids with diethanolamine, found in many shampoos and body washes. IARC lists it as possibly carcinogenic to humans, and California added it to its Proposition 65 list. It may also contain free DEA, which can form nitrosamines. Cocamidopropyl betaine is a common swap. Read the full guide

Cocoa Butter Natural

Also listed as: theobroma cacao seed butter, cacao butter

A firm, naturally fragrant fat pressed from cacao beans, used in lip balms, body butters and soaps. It melts at body temperature, forms a protective layer that helps skin retain moisture, and adds hardness to balms and bars. Unrefined cocoa butter smells like chocolate. Some people find it heavy on acne prone facial skin. Read the full guide

Coconut Oil Natural

Also listed as: cocos nucifera oil, sodium cocoate, fractionated coconut oil

An oil pressed from coconut meat, high in lauric acid. In cold process soap it creates big, fluffy lather and a hard bar, appearing on labels as sodium cocoate once saponified. As a moisturizer it suits the body and hair well. It can clog pores for some people when used on the face, and too much in soap can feel drying. Read the full guide

Cyclomethicone Use with care

Also listed as: cyclic silicones

A general label name for a mix of cyclic silicones, usually D4, D5 and D6. These lightweight fluids give a silky, quick drying feel to hair serums, primers and antiperspirants, then evaporate. They are low in irritation, but the EU has restricted D4, D5 and D6 in many products because they persist and build up in the environment. Read the full guide

Cyclopentasiloxane Use with care

Also listed as: D5, decamethylcyclopentasiloxane

A cyclic silicone (D5) that gives serums, foundations and hair products a smooth, weightless slip before it evaporates. It rarely irritates skin. The concern is environmental persistence, and the EU has restricted it in wash off and, more recently, leave on products. D4, a related silicone, has raised reproductive concerns in animal studies. Read the full guide

D

DBP We avoid

Also listed as: dibutyl phthalate, di-n-butyl phthalate

A phthalate plasticizer once common in nail polish to keep it flexible and chip resistant. Animal studies have linked DBP to reproductive and developmental effects, and the EU bans it in cosmetics. Most major nail brands removed it years ago, which is where the "3 free" label comes from. It is now rarely found in US personal care products. Read the full guide

DEHP We avoid

Also listed as: di(2-ethylhexyl) phthalate, bis(2-ethylhexyl) phthalate, diethylhexyl phthalate

A phthalate used mainly to soften PVC plastics rather than as a cosmetic ingredient. It is banned in EU cosmetics and listed under California Proposition 65 for reproductive toxicity. Exposure today comes mostly from food packaging and plastics, though it can migrate from packaging into products. Animal research links it to hormone disruption. Read the full guide

Diazolidinyl Urea We avoid

Also listed as: Germall II

A formaldehyde releasing preservative used in lotions, shampoos and makeup. It works by slowly releasing small amounts of formaldehyde, which protects the product from microbes but can trigger allergic contact dermatitis in sensitive people. The EU and US safety reviewers permit it at limited concentrations, up to 0.5 percent in the EU. Read the full guide

Diethanolamine We avoid

Also listed as: DEA

An ethanolamine used to adjust pH and create foam, and as a building block for ingredients like cocamide DEA. On its own it can react with nitrosating agents to form NDELA, a nitrosamine. The EU bans DEA as a cosmetic ingredient. In the US, safety reviewers advise against using it in products that contain nitrosating agents. Read the full guide

Diethyl Phthalate We avoid

Also listed as: DEP

The phthalate most often found in personal care products today, used to help fragrances last. Because it can hide inside "fragrance" or "parfum," it rarely appears on labels by name. The EU and the FDA still permit it, and evidence of harm at cosmetic levels is limited, but its presence in urine samples leads many people to choose phthalate free products. Read the full guide

Dimethicone Use with care

Also listed as: polydimethylsiloxane, PDMS, amodimethicone

A linear silicone that forms a smooth, breathable film in moisturizers, primers, diaper creams and conditioners. It is considered safe and rarely irritates skin, which is why it also appears in skin protectant products. Some people find it builds up on hair. Unlike cyclic silicones, it is not under regulatory restriction. Read the full guide

DMDM Hydantoin We avoid

Also listed as: dimethylol dimethyl hydantoin, Glydant

A formaldehyde releasing preservative found mainly in shampoos, conditioners and body washes. It slowly releases small amounts of formaldehyde, a known human carcinogen and common skin allergen, to keep products free of microbes. The EU allows it at up to 0.6 percent. It has been the subject of US lawsuits over scalp irritation and hair loss claims. Read the full guide

E

Epsom Salt Natural

Also listed as: magnesium sulfate, magnesium sulfate heptahydrate

A mineral compound of magnesium and sulfate, named after a spring in Epsom, England. It is a classic in bath soaks for relaxing tired muscles and softening skin. Evidence that meaningful magnesium absorbs through skin is limited, but a warm soak is relaxing in itself. Unscented, dye free salts are the gentlest choice. Read the full guide

F

FD&C Red 40 Use with care

Also listed as: Allura Red AC, CI 16035, Red 40, E129

A synthetic azo dye, made from petroleum, used in lip products, mouthwash, soaps and bath products. The FDA certifies each batch before use. Most attention around Red 40 involves food and children's behavior, and skin reactions from cosmetics are uncommon. In the EU it is listed by its color index number, CI 16035. Read the full guide

Formaldehyde We avoid

Also listed as: formalin, methanal, methylene glycol

A preservative and hair straightening agent that IARC classifies as a known human carcinogen. It is rarely listed directly in cosmetics today; more often it is released by preservatives such as DMDM hydantoin or appears as methylene glycol in keratin treatments. It is a common contact allergen, and the EU bans it as an added cosmetic ingredient. Read the full guide

G

Galaxolide We avoid

Also listed as: HHCB, hexamethylindanopyran

A polycyclic synthetic musk used to give perfume, detergents, lotions and soaps a clean, lasting scent. It is usually hidden within "fragrance" on labels. Research has found it in human fat, breast milk and waterways, and some lab studies suggest hormone activity. Regulators still permit it, but its persistence leads many to avoid it. Read the full guide

Glycerin Natural

Also listed as: glycerol, vegetable glycerin

A humectant that draws water into the skin, found in soaps, lotions and cleansers. It forms naturally during saponification, and cold process soap keeps it in the bar, while many commercial makers remove it to sell separately. Glycerin can come from plant oils, animal fats or petroleum. It is very well tolerated. Read the full guide

H

Hemp Seed Oil Natural

Also listed as: cannabis sativa seed oil, hempseed oil

A green, light oil pressed from hemp seeds, rich in linoleic and alpha linolenic acids. It conditions hair and moisturizes skin without feeling heavy. Hemp seed oil is not the same as CBD oil and contains little or no THC or CBD. It oxidizes fairly quickly, so it is best kept cool and used within its shelf life. Read the full guide

Homosalate We avoid

Also listed as: homomenthyl salicylate

A chemical UVB filter common in US sunscreens. FDA testing shows it absorbs into the bloodstream, and EU scientific reviewers raised questions about possible hormone effects. The EU now limits it to 7.34 percent and only in face products. The FDA has asked manufacturers for more safety data before calling it generally recognized as safe. Read the full guide

Hydroquinone We avoid

A skin lightening agent that reduces melanin production, used to fade dark spots and melasma. Since 2020 it is no longer sold over the counter in the US and requires a prescription, and the EU bans it in cosmetics. Long term or unsupervised use has been linked to irritation and ochronosis, a bluish black darkening of the skin. Read the full guide

I

Imidazolidinyl Urea We avoid

Also listed as: Germall 115

A formaldehyde releasing preservative found in creams, shampoos, sunscreens and makeup. It slowly releases formaldehyde to keep products free of bacteria and is a recognized cause of allergic contact dermatitis, especially for people already sensitive to formaldehyde. The EU permits it at up to 0.6 percent, and US safety reviewers consider it acceptable at limited levels. Read the full guide

J

Jojoba Oil Natural

Also listed as: simmondsia chinensis seed oil, jojoba wax

A liquid wax pressed from the seeds of the jojoba shrub, native to the Sonoran Desert. Its structure resembles the wax esters in human sebum, so it absorbs comfortably and suits many skin types, including oily skin. It is very stable and resists rancidity. Golden jojoba is unrefined, while clear jojoba is filtered. Read the full guide

L

Lavender Oil Use with care

Also listed as: lavandula angustifolia oil, lavender essential oil

An essential oil steam distilled from lavender flowers, loved for its calming scent in soaps, balms and bath products. It is one of the most popular essential oils, but it contains linalool and linalyl acetate, which can oxidize and cause skin reactions in some people. Diluting it and storing it tightly capped helps. Read the full guide

Lead Acetate We avoid

Also listed as: plumbous acetate

A lead compound once used in gradual or progressive hair dyes for men, which darken gray hair over repeated use. The FDA repealed its approval for use in hair dyes, and the EU has long banned it. Lead has no known safe level of exposure. Lead can also show up as an impurity in some lipsticks and kohl eyeliners, usually at low levels. Read the full guide

Linalool Use with care

A floral scent compound that occurs naturally in lavender, coriander and many other plants and is also made synthetically. Like limonene from citrus, it can oxidize into stronger allergens over time. The EU lists it as a fragrance allergen that must appear on labels above set levels. Most people use it without trouble, but it can affect fragrance sensitive skin. Read the full guide

Lye Relaxer We avoid

Also listed as: sodium hydroxide relaxer, guanidine hydroxide, no lye relaxer, calcium hydroxide relaxer

A chemical straightener that uses strong alkalis such as sodium hydroxide to break bonds in the hair shaft. These products can cause scalp burns and breakage. The NIH Sister Study found that frequent use of hair straightening products was associated with higher uterine cancer risk, though it did not single out one ingredient. Read the full guide

M

Methylchloroisothiazolinone We avoid

Also listed as: MCI, MCI/MI, Kathon CG

A strong preservative usually paired with methylisothiazolinone (MI) in shampoos, cleaners and some wipes. The combination is effective at very low levels but is a well known cause of allergic contact dermatitis. The EU allows the MCI/MI mix only in rinse off products, at no more than 15 parts per million. Read the full guide

Methylisothiazolinone We avoid

Also listed as: MI, MIT, 2-methyl-4-isothiazolin-3-one

A preservative used in shampoos, conditioners, wipes and household cleaners. Its rise led to a wave of allergic contact dermatitis, and dermatologists named it Allergen of the Year in 2013. The EU banned it in leave on cosmetics and limits it to 15 parts per million in rinse off products. Once sensitized, people often react to very small amounts. Read the full guide

Methylparaben Use with care

Also listed as: methyl paraben, methyl 4-hydroxybenzoate, E218

The most widely used paraben, a preservative that prevents mold and bacteria in creams, cleansers and makeup. Short chain parabens like methylparaben show weaker estrogen-like activity than butyl or propylparaben. The FDA and EU consider it safe at typical levels, up to 0.4 percent alone in the EU, though many shoppers prefer paraben free products. Read the full guide

N

NDELA We avoid

Also listed as: N-nitrosodiethanolamine, nitrosamines

A nitrosamine contaminant that can form inside products when DEA, TEA or related amines meet nitrosating agents such as certain preservatives. IARC classifies it as possibly carcinogenic to humans, and it can absorb through skin. It is never listed on labels. The EU prohibits nitrosamines in cosmetics and limits ingredients prone to forming them. Read the full guide

O

Octinoxate We avoid

Also listed as: ethylhexyl methoxycinnamate, octyl methoxycinnamate, OMC

A chemical UVB filter used in sunscreens and SPF makeup. It absorbs into the body, and some animal and lab studies suggest hormone activity. Hawaii and Key West restricted its sale over concerns about coral reefs. The EU permits it at up to 10 percent, and the FDA has asked for more safety data before confirming its status. Read the full guide

Octocrylene We avoid

A chemical UV filter often used to stabilize avobenzone in sunscreens. Research has found that octocrylene can degrade into benzophenone, a possible carcinogen, as products age. It is also a known cause of photoallergy in some people. The EU permits it at up to 10 percent, and the FDA has requested more safety data. Read the full guide

Olive Oil Natural

Also listed as: olea europaea fruit oil, sodium olivate

A classic oil pressed from olives, the base of traditional Castile soap. In soap it creates a gentle, conditioning bar and appears as sodium olivate after saponification. On skin it softens and moisturizes, thanks to oleic acid and natural antioxidants. Most people tolerate it well, though some with very dry or eczema prone skin prefer other oils. Read the full guide

Oxybenzone We avoid

Also listed as: benzophenone-3, BP-3

A chemical UV filter that absorbs into the body more than most, according to FDA studies. It is a known contact and photo allergen, and some research suggests hormone activity. Hawaii restricted its sale to protect coral reefs, and the EU limits it to 6 percent in body and face products. The FDA has requested more safety data. Read the full guide

P

p-Phenylenediamine We avoid

Also listed as: PPD, para-phenylenediamine, CI 76060

The key dye ingredient in most permanent dark hair colors, and a strong skin sensitizer. Reactions can range from itching to severe swelling, and they are notorious with "black henna" temporary tattoos. The EU limits it in hair dye and bans it on skin. The FDA advises a patch test before every use of hair dye. Read the full guide

Paraffinum Liquidum Use with care

Also listed as: mineral oil, liquid paraffin, white mineral oil, paraffin oil

The INCI name for mineral oil, a petroleum derived oil used in baby oils, lotions, cleansers and makeup. Cosmetic grade mineral oil is highly refined and is not classified as a carcinogen, unlike crude or poorly refined oils. It locks in moisture well but offers no nutrients, and some people find it feels heavy or clogs their pores. Read the full guide

Parfum We avoid

Also listed as: fragrance, aroma, perfume

A single label word that can stand for dozens of undisclosed scent chemicals, because fragrance formulas are protected as trade secrets. It may include phthalates or synthetic musks. Fragrance is one of the most common causes of cosmetic skin allergies. Products scented only with named essential oils are easier to evaluate. Read the full guide

PEG-100 Stearate Use with care

Also listed as: polyethylene glycol stearate, PEG stearate

An ethoxylated emulsifier, often paired with glyceryl stearate, that helps oil and water blend in creams and lotions. Safety panels consider PEGs safe for intact skin but advise caution on damaged skin. Because ethoxylation can leave traces of 1,4-dioxane, some brands avoid PEGs or rely on suppliers who remove it. Read the full guide

Peppermint Oil Use with care

Also listed as: mentha piperita oil, peppermint essential oil

An essential oil with a cooling, minty scent from menthol, used in foot balms, lip balms, shampoos and insect repellents. It can feel tingly and refreshing at low levels but irritating at higher ones. It should be well diluted, kept away from the eyes, and not used on the faces of infants and young children. Read the full guide

Perfluorooctyl Triethoxysilane We avoid

Also listed as: perfluorooctyltriethoxysilane

A fluorinated compound used to coat pigments and powders so foundation and pressed powder resist water and glide on smoothly. It belongs to the PFAS family, often called forever chemicals because they persist in the environment and the body. Several US states now restrict intentionally added PFAS in cosmetics. Watch for "perfluoro" or "fluoro" on labels. Read the full guide

Petrolatum Use with care

Also listed as: petroleum jelly, white petrolatum, paraffinum molle

A semisolid blend of hydrocarbons from petroleum refining, used in lip balms, ointments and baby products. It is an effective occlusive that seals in moisture. Fully refined petrolatum is considered safe, and the EU requires the refining history to be known to rule out contamination with polycyclic aromatic hydrocarbons. Beeswax and plant butters are natural alternatives. Read the full guide

Phenoxyethanol Use with care

Also listed as: 2-phenoxyethanol, ethylene glycol monophenyl ether

A widely used preservative and a common replacement in paraben free products. The EU allows it at up to 1 percent, and safety reviewers consider it safe at that level. It can irritate sensitive skin or eyes and occasionally causes allergic reactions. The FDA has warned about its use in nipple creams because of risks to nursing infants who ingest it. Read the full guide

Polyethylene We avoid

Also listed as: PE, polyethylene beads

A plastic used as tiny beads in scrubs and as a thickener or film former in makeup and lotions. The US banned plastic microbeads in rinse off products in 2015, and the EU restricted intentionally added microplastics in 2023. Plastic can still appear in leave on products and glitter. Natural exfoliants like sugar or salt avoid the issue. Read the full guide

Polysorbate 20 Use with care

Also listed as: polyoxyethylene sorbitan monolaurate, Tween 20

An ethoxylated solubilizer that lets oils and fragrances dissolve into water based products like toners, body sprays and micellar water. Safety reviewers consider it safe and mild in typical amounts. Like other ethoxylated ingredients, it may carry trace 1,4-dioxane, which careful manufacturers reduce through purification. Read the full guide

Prickly Pear Seed Oil Natural

Also listed as: opuntia ficus-indica seed oil, barbary fig seed oil, cactus seed oil

A light facial oil cold pressed from the tiny seeds of the prickly pear cactus. It is rich in linoleic acid and vitamin E and absorbs quickly without a greasy feel. It is expensive because a large amount of fruit yields only a small amount of oil. It suits most skin types and rarely irritates. Read the full guide

Propylene Glycol Use with care

Also listed as: 1,2-propanediol, PG

A humectant and solvent used in moisturizers, deodorant sticks, hair products and cleansers. It helps ingredients penetrate skin and keeps products from drying out. It is considered safe at typical levels, but dermatologists named it Allergen of the Year in 2018 because it can irritate or sensitize some people, especially those with eczema. Read the full guide

Propylparaben We avoid

Also listed as: propyl paraben, propyl 4-hydroxybenzoate

A paraben preservative used in lotions, makeup and hair care. It shows more estrogen-like activity in lab studies than shorter chain parabens. The EU caps propyl and butylparaben combined at 0.14 percent and bans them in leave on diaper area products for young children. The FDA has not found that parabens at typical levels harm health. Read the full guide

PTFE We avoid

Also listed as: polytetrafluoroethylene, Teflon

A fluoropolymer, best known as nonstick coating, used in foundations, powders, eye shadows and shaving creams for a silky slip. PTFE belongs to the PFAS family. The polymer itself is considered inert, but its manufacture and breakdown raise environmental concerns. A number of US states now restrict intentionally added PFAS in cosmetics. Read the full guide

Q

Quaternium-15 We avoid

Also listed as: Dowicil 200, cis-1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride

A formaldehyde releasing preservative once common in shampoos, lotions and baby products. It is one of the more frequent causes of preservative allergy in patch tests. The EU no longer allows it in cosmetics. In the US it is still permitted, though many brands have voluntarily removed it. Read the full guide

R

Resorcinol Use with care

Also listed as: 1,3-benzenediol, m-dihydroxybenzene

A coupling ingredient in permanent hair dyes that works with PPD to develop color, also used in some acne and peel products. It can irritate skin and cause allergic reactions. At high exposures it has affected thyroid function, though cosmetic use is lower. The EU limits its concentration and requires warning labels on hair dyes that contain it. Read the full guide

Rice Bran Oil Natural

Also listed as: oryza sativa bran oil, oryza sativa (rice) bran oil

An oil pressed from the outer layer of rice grains, used in hair oils, soaps and moisturizers. It contains gamma oryzanol and vitamin E compounds that act as natural antioxidants. It is light and conditioning, helping hair look smooth without heavy buildup. It is mild and suits most hair and skin types. Read the full guide

Rosehip Seed Oil Natural

Also listed as: rosa canina fruit oil, rosa rubiginosa seed oil, rosehip oil

A facial oil pressed from the seeds of wild rose fruit, rich in linoleic and alpha linolenic acids. It helps skin feel soft and supports a more even looking tone. The oil itself contains little vitamin C, despite common claims. It oxidizes quickly, so a dark bottle, cool storage and a sensible shelf life matter. Read the full guide

S

Sacha Inchi Oil Natural

Also listed as: plukenetia volubilis seed oil, Inca peanut oil

An oil pressed from the seeds of sacha inchi, a plant native to the Amazon. It is one of the richest plant sources of omega 3 alpha linolenic acid, and it feels light on hair and skin. It helps condition dry hair and add soft shine without weighing it down. Like other omega rich oils, it should be kept away from heat. Read the full guide

Saponified Oils Natural

Also listed as: sodium olivate, sodium cocoate, sodium shea butterate, sodium castorate

The label term for oils and butters that have reacted with lye to become true soap. In INCI form they appear as names like sodium olivate or sodium cocoate. A cold process bar made this way keeps its natural glycerin and needs no synthetic detergents. Any soap is alkaline, so very sensitive skin may prefer superfatted bars. Read the full guide

Sea Salt Natural

Also listed as: maris sal, sodium chloride, dead sea salt

Salt from evaporated seawater, used in bath soaks and scrubs. It contains sodium chloride plus small amounts of minerals such as magnesium, calcium and potassium. A sea salt bath can help skin feel clean and soft, and coarse salt makes a natural exfoliant. Salt can sting cuts or freshly shaved skin. Read the full guide

Shea Butter Natural

Also listed as: butyrospermum parkii butter, vitellaria paradoxa butter, karite butter

A rich butter from the nuts of the African shea tree, used in balms, body butters, soaps and hair products. It is high in oleic and stearic acids and naturally contains vitamins A and E. It softens dry skin and lips and helps hold in moisture. Although shea is a tree nut, reactions to the butter are rare. Read the full guide

Sodium Bicarbonate Use with care

Also listed as: baking soda, bicarbonate of soda

Baking soda, an alkaline mineral salt used in natural deodorants, bath soaks and toothpastes. It neutralizes odor well, but its high pH can irritate underarms for some people, causing redness or a rash. Using less, applying to dry skin, or choosing a baking soda free formula usually solves the problem. Read the full guide

Sodium Hydroxide Use with care

Also listed as: lye, caustic soda

A strong alkali, also called lye, that every true soap needs. In cold process soap it reacts with oils during saponification, and none remains in a properly made and cured bar. In small amounts it also adjusts pH in creams. On its own it is caustic, which is why it is a concern in lye based hair relaxers. Read the full guide

Sodium Laureth Sulfate We avoid

Also listed as: SLES, sodium lauryl ether sulfate

A foaming surfactant in many shampoos, body washes and bubble baths. It is somewhat milder than SLS, but it can still dry skin and hair. Because it is made through ethoxylation, it may contain trace 1,4-dioxane. Safety reviewers consider it safe in rinse off products when formulated to be non irritating. Read the full guide

Sodium Lauryl Sulfate We avoid

Also listed as: SLS, sodium dodecyl sulfate

A powerful detergent that creates rich foam in shampoos, body washes and toothpastes. It is so reliably irritating at higher levels that researchers use it to test skin irritation. Safety reviewers consider it acceptable in rinse off products with short contact time. Some research has linked SLS toothpaste to more frequent canker sores in prone people. Read the full guide

Sweet Almond Oil Natural

Also listed as: prunus amygdalus dulcis oil, almond oil

A light, gentle oil pressed from sweet almonds, popular as a massage oil and as a carrier for essential oils. It is high in oleic acid and spreads easily without feeling heavy. It suits most skin types. People with a tree nut allergy should check with their doctor before using almond oil products. Read the full guide

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Talc Use with care

Also listed as: talcum powder, magnesium silicate, CI 77718

A soft mineral used in body powders, eye shadows, blushes and dry shampoo to absorb oil and add silky slip. The main worry is contamination with asbestos, which can occur in talc deposits. IARC classified talc as probably carcinogenic to humans in 2024, and the FDA has proposed asbestos testing rules. Arrowroot and cornstarch are common substitutes. Read the full guide

Tea Tree Oil Use with care

Also listed as: melaleuca alternifolia leaf oil, tea tree essential oil

An essential oil from an Australian shrub, known for its fresh, medicinal scent. It appears in soaps, shampoos, men's grooming products and blemish products. It is popular for skin that tends to break out, but oxidized tea tree oil can cause allergic reactions. Keep it diluted, capped and fresh, and avoid using it undiluted. Read the full guide

Titanium Dioxide Use with care

Also listed as: CI 77891, TiO2

A white mineral used as a sunscreen filter and as a pigment in makeup and toothpaste. On skin it is considered safe, and the FDA has proposed that it is generally recognized as safe for sunscreens. IARC classifies it as possibly carcinogenic when inhaled as a fine powder, so creams are preferred over loose powders and sprays. Read the full guide

Tocopherol Natural

Also listed as: vitamin E, tocopheryl acetate, mixed tocopherols

Vitamin E, a natural antioxidant that helps protect oils and butters from going rancid and helps skin feel soft and supple. It does not stop bacteria or mold, so it is not a preservative on its own. Tocopheryl acetate is a more stable form. It is well tolerated, though rare allergic reactions have been reported. Read the full guide

Toluene We avoid

Also listed as: methylbenzene, toluol

A solvent that helps nail polish go on smoothly and dry quickly, and part of the "toxic trio" with DBP and formaldehyde. Breathing high levels of its vapor can cause headaches and dizziness, and heavy exposure has been linked to reproductive harm. It is still permitted in nail products, but "3 free" and similar polishes leave it out. Read the full guide

Tonalide We avoid

Also listed as: AHTN, acetyl hexamethyl tetralin

A polycyclic synthetic musk used in perfumes, detergents, lotions and soaps for a lasting scent. Like galaxolide, it persists in the environment and has been detected in human tissue and breast milk. Some lab studies suggest it may interfere with hormone signaling. The EU sets maximum levels for tonalide in different cosmetic product types. Read the full guide

Triclocarban We avoid

Also listed as: TCC, trichlorocarbanilide

An antibacterial agent once common in bar soaps. In 2016 the FDA removed it, along with triclosan, from over the counter consumer antiseptic washes because makers had not shown that it was safe for long term use or better than plain soap and water. It persists in waterways and sediment. Read the full guide

Triclosan We avoid

Also listed as: TCS, 5-chloro-2-(2,4-dichlorophenoxy)phenol

An antibacterial chemical once found in liquid hand soaps, body washes and toothpaste. The FDA removed it from consumer antiseptic washes in 2016, citing a lack of evidence that it was safer or more effective than plain soap. Research has raised questions about hormone effects and antibiotic resistance, and it persists in the environment. Read the full guide

Triethanolamine Use with care

Also listed as: TEA, trolamine

A pH adjuster and emulsifier used in lotions, mascaras, shaving creams and cleansers, also seen in names like TEA lauryl sulfate. Safety reviewers consider it safe when formulated to be non irritating, but it can irritate at higher concentrations. Like DEA, it may form nitrosamines if combined with nitrosating ingredients. Read the full guide

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Zinc Oxide Natural

Also listed as: CI 77947, non nano zinc oxide

A white mineral used as a broad spectrum sunscreen filter and in diaper creams and skin protectants. It sits on the skin and helps block both UVA and UVB rays. The FDA has proposed that zinc oxide is generally recognized as safe for sunscreens. It can leave a white cast, and non nano particles are less likely to be inhaled or absorbed. Read the full guide