The formulation index.

The workhorse preservative replacing parabens in most modern formulas.

Capped at 1% in the EU and Australia. Stable, broad-spectrum, with a long human-safety record at use concentration. Yuka flags it red on principle. We don't — not at 0.4% in a serum that needs water-system protection. The alternative, in most cases, is a contaminated product.

The short-chain parabens still cleared for cosmetic use under 0.4% individually.

The 2004 breast-tissue paper that triggered the paraben panic never demonstrated causation, and the methodology has not held up. Methyl- and ethyl-paraben remain among the better-studied preservatives in cosmetics. Brands have largely moved on; the formulas that kept them aren't worse for it.

The longer-chain parabens with endocrine-disruption signal in animal data.

Banned in cosmetics across the EU since 2014. Should not be in a 2026 formula. If you see one of these in an INCI list, it's either an old SKU on shelf or a brand running a poor regulatory line.

Quaternium-15, DMDM hydantoin, imidazolidinyl urea — preservatives that release formaldehyde over time.

IARC Group 1 carcinogen on the release end. Sensitiser at low concentrations. There are better preservative systems in 2026 and almost every reputable brand has moved off them. We flag any product carrying one.

Antibacterial agent in older soaps, deodorants, toothpastes.

Endocrine and antimicrobial-resistance signals. Banned in EU cosmetics since 2017. Effectively gone from Australian formulations; flagged on principle if it appears.

Synthetic antioxidants used to stabilise oils. Not the same BHA as salicylic acid.

In-vitro hazard signals, no settled clinical concern at cosmetic concentration. Mostly tracked as an environmental-persistence flag. Common in lip balms and oil-based products; we note it, we don't downgrade for it.

Mineral broad-spectrum filter. The only single ingredient that covers the full UVA-UVB range.

No systemic absorption concern. Photo-stable. The reason most Australian dermatologists default to it. The trade-off is cosmetic: it tints, and at the concentrations that reach SPF 50 it can ghost. Worth it.

The other mineral filter. UVB-strong, UVA-weaker than zinc.

Long-cleared in topical use. The nano-grade inhalation flag applies to powders, not creams. Often paired with zinc to lift the UVB end of a mineral formula.

The new-generation organic UVA filters. Approved in Australia and the EU; not in the US.

Cover the deep-UVA range (380nm+) where older chemical filters fall away. Photo-stable, no endocrine signal. The reason the best UVA protection on the market right now is in European and Australian sunscreens, not American ones.

The standard organic UVA filter in older formulas.

Effective but photo-degrades quickly — needs octocrylene or a Tinosorb pairing to hold up across a day. A solo-avobenzone formula isn't doing the job after lunch. We check the partner filters.

Photo-stabiliser usually used to prop up avobenzone.

A 2021 study flagged benzophenone formation in degraded octocrylene; the practical risk at use concentration is small but real. Most reformulations are moving toward Tinosorb instead. Acceptable inside the limit; we note it on the score sheet.

The chemical filter banned in Hawaii and Palau for reef toxicity.

Endocrine signal stronger than most other chemical filters. Reef toxicity established. Largely reformulated out of Australian and European sunscreens; if you see it on a 2026 SKU, the formulation team didn't keep up.

Vitamin A derivatives. The most clinically supported anti-ageing active in cosmetic skincare.

Forty years of human data. Real photo-ageing, fine-line and pigmentation results from 0.3% retinol up. The watch is on pregnancy — oral isotretinoin is teratogenic and the precaution extends to topicals. Otherwise the standard. Pair with SPF.

Vitamin B3. The barrier and pigmentation active with the cleanest tolerance profile in skincare.

Works at 2-5%. The 10% concentration that became popular around 2020 doesn't out-perform 5% and tips into irritation for sensitive skin. The one active almost every skin type can wear daily.

Oil-soluble exfoliant. The only acne ingredient with twenty years of clinical settlement.

Yuka flags it red. It is the safest, best-evidenced congestion treatment on the market. Pregnancy guidance is for high-concentration peels, not 2% leave-ons. The cleanser-format under 2% is fine.

The most penetrating AHA. The reference acid for tone and texture work.

Increases UV sensitivity for up to a week post-use. The SPF habit is non-negotiable. Effective from 5% up; the at-home limit in Australia is 10%, and you don't need higher.

The reference antioxidant. The morning step the dermatology community defends hardest.

Photo-protective, pigment-clearing, collagen-supportive. Stable as L-ascorbic acid only at low pH in an opaque, airless format — most "vitamin C" serums oxidise on shelf. Derivatives (MAP, SAP, ascorbyl glucoside) are gentler but slower. Either has a place.

The reference active for inflammatory acne. The cheap one that works.

Bleaches towels and pillowcases. Dries skin in week one. Resistance-free unlike topical antibiotics. The 2.5% strength holds up against 10% on tolerance without losing efficacy.

The strongest topical pigment-lightener cleared for medical use.

Schedule 4 in Australia — prescription only. Effective for melasma; ochronosis risk on prolonged unsupervised use is real. Anything sold over-the-counter as "hydroquinone-free brightening" is, by definition, not as strong. That's appropriate.

An older pigmentation and acne active, also used in some hair dyes.

Thyroid signal in animal data. Largely reformulated out of cosmetic skincare. Flag if it appears at any concentration outside of a regulated hair-dye context.

Humectant. The headline hydration ingredient, low and high molecular weight.

Pulls water from the environment in humid weather; pulls it from the skin in dry weather, which is why a serum without an occlusive on top can leave skin tighter than it started. The headline is real; the application context matters.

The lipids that make up the skin's outer barrier. The most quietly effective category in modern skincare.

The CeraVe formula that became a derm default rides on a ceramide-1, -3, -6-II ratio. Ageing, low-humidity climates and over-actived routines deplete them; topical ceramides restore them. No tolerance ceiling.

Hydrogenated squalene, the lipid the skin already makes. The cleanest occlusive in cosmetic use.

Non-comedogenic on the consensus data. The Beauty Pie / Biossance / The Ordinary version of an oil step. A genuine alternative to silicone for users who want a finishing layer that breathes.

The standard antioxidant pairing for vitamin C and most oil-phase formulas.

Stabilises C, supports the barrier, no concern flag at cosmetic concentration. The unremarkable ingredient in almost every good formula.

The slip ingredients. The reason a primer or serum spreads the way it does.

No clinical case for the "silicones suffocate skin" line. They don't penetrate the barrier; they sit on top, fill, and wash off. Cyclopentasiloxane is being phased out for environmental persistence in some markets; dimethicone isn't.

Petrolatum-derived occlusive. The most studied moisturiser ingredient in cosmetic history.

Cosmetic-grade mineral oil is highly purified and the comedogenicity charge is overstated — it scores low on the modern consensus. The reason it gets a B and not an A is sustainability optics, not skin performance.

The wellness-industrial oil. Beloved in body care, complicated on the face.

Comedogenic rating of 4 on the standard scale. Fine in body care for most users; we flag it on facial formulations for any skin that tends to break out. The TikTok "I rub it on my face" generation usually finds out.

Wool-derived emollient. The original lip-balm and rash-cream lipid.

Genuinely effective for chapped lips and barrier rescue. Common allergen — not for sensitised skin or known wool reactions. We flag it but don't downgrade a product that uses it well.

The classic foaming surfactants in cleansers, shampoos, body washes.

SLS is the harsher of the two; SLES is gentler but a manufacturing-process concern (1,4-dioxane contamination) means we prefer modern alternatives. On a daily face cleanser we flag both. On a shampoo for unsensitised scalps, they're fine.

Emulsifier-solubilisers across the formulation industry. The number after PEG is molecular weight.

Cosmetic-grade PEGs are well-purified and the 1,4-dioxane line that floats around clean-beauty marketing is a manufacturing-control issue, not an ingredient issue. We note them, we don't downgrade.

The drying alcohols — ethanol, alcohol denat, SD alcohol — used as fast-evaporating carriers.

Useful in oily-skin toners and acne treatments where you want fast evaporation. A problem high in the INCI list of a hydrator or moisturiser for any skin that runs dry. The "fatty alcohols" (cetyl, stearyl) are the opposite category and don't apply.

Botanical astringent. The wellness-counter staple in toners and "calming" products.

The plant extract itself is mild. The standard manufacturing process uses high-strength alcohol that stays in the bottle. Reads on the alcohol flag, not the witch-hazel flag.

The catch-all ingredient name covering any combination of up to thousands of disclosed and undisclosed compounds.

The single biggest source of contact dermatitis in cosmetics. EU disclosure rules now force 26 named allergens onto labels but the rest of the formula stays opaque. We flag it on every leave-on product for any user prone to reaction.

The 26 EU-listed compounds that must appear by name when present above 0.001% in leave-on products.

Oxidise over time into more sensitising forms. The reason an old serum can suddenly start reacting on skin that tolerated it new. We flag.

Plant-distilled fragrance compounds in "natural" formulations.

The "natural therefore safe" argument doesn't survive a patch-test panel. Tea tree, lavender, peppermint and citrus oils are common reactors. We treat them on the same flag as synthetic fragrance, sometimes more strict.

Plasticiser compounds historically used as fragrance carriers and nail-polish softeners.

DEHP and DBP are restricted in EU cosmetics. DEP remains in widespread fragrance use and rarely appears on labels because "fragrance" covers it. The hardest ingredient to track honestly, and a real concern at the systemic-exposure end.

The colour-index codes for FDA / EU-approved cosmetic dyes.

Most colour cosmetics in the world use them. Approval lists are different by market — an EU-approved formula will sometimes use a lake the US prohibits. Within market approval, no concern at use concentration.

The mineral powder base in setting powders, blushes, body powders.

The historic concern is asbestos contamination at the mine. Reputable brands now certify asbestos-free and we check. The flag is on traceability, not talc itself.

The aluminium chlorohydrate / zirconium compounds that make antiperspirants actually antiperspirant.

The breast-cancer link has not held up under repeated review. The trade-off is real: aluminium-free "natural" deodorants don't stop sweat, they mask odour. If wetness control is the job, the alternative is worse skincare in another way.