red
N-Hydroxyethyl-P-Phenylenediamine
Active dye in most permanent hair colours. Severe contact allergen.
Krasteva et al. Contact Dermatitis 2009
Low Tox Gear · Scanner
L'Oreal Paris Preference Hair Colour 4 Brown each
Is L'Oreal Paris Preference Hair Colour 4 Brown each low tox? Our scanner flagged 8 ingredients (1 in the avoid tier, 7 caution) on its published label, screened against our 237 source-cited chemical rules.
1 avoid7 caution
8 ingredients flagged
What we flagged
amber
Glycol PEG
Manufacturing process can leave 1,4-dioxane (probable carcinogen) and ethylene oxide as contaminants. Look for 'vacuum-stripped' products.
amber
Alcohol Denat
Strips skin barrier — flares eczema, rosacea and psoriasis.
amber
Propylene Glycol
Common humectant. Documented contact allergen — especially for eczema-prone skin.
amber
Sodiummetabisulfite
Documented MCAS, asthma and migraine trigger in sensitive individuals.
amber
M-Aminophenol
PPD-family hair-dye intermediate.
amber
Resorcinol
Hair-dye coupler with thyroid-disrupting activity in animal studies.
amber
Resorcinol EDTA
Chelating agent — generally tolerated but documented MCAS trigger in case reports.
Full ingredients (from label)
Colourant Gel:AQUA /WATER TRIDECETH-2 CARBOXAMIDE MEA PROPYLENE GLYCOL HEXYLENE GLYCOL PEG-2OLEAMINE POLYGLYCERYL-4 OLEYL ETHER OLEYL ALCOHOL ALCOHOL DENAT. AMMONIUMHYDROXIDE POLYGLYCERYL-2 OLEYL ETHER OLEIC ACID SODIUM DIETHYLAMINOPROPYLCOCOASPARTAMIDE 24-DIAMINOPHENOXYETHANOL HCL m-AMINOPHENOL SODIUMMETABISULFITE HYDROXYPROPYL BIS(N-HYDROXYETHYL-P-PHENYLENEDIAMINE) HCL AMMONIUMACETATE NN-BIS(2-HYDROXYETHYL)-p-PHENYLENEDIAMINE SULFATE p-PHENYLENEDIAMINE RESORCINOL EDTA ERYTHORBIC ACID PARFUM / FRAGRANCE.Developer CreamAQUA / WATER HYDROGEN PEROXIDE CETEARYL ALCOHOL SODIUM SALICYLATE TRIDECETH-2CARBOXAMIDE MEA PHOSPHORIC ACID CETEARETH-25 TETRASODIUM ETIDRONATE TETRASODIUM PYROPHOSPHATE GLYCERIN.Shine Protect CondtionerAQUA /WATER TRIDECETH-2 CARBOXAMIDE MEA PROPYLENE GLYCOL HEXYLENE GLYCOL PEG-2OLEAMINE POLYGLYCERYL-4 OLEYL ETHER OLEYL ALCOHOL ALCOHOL DENAT. POLYGLYCERYL-2OLEYL ETHER AMMONIUM HYDROXIDE OLEIC ACID SODIUM DIETHYLAMINOPROPYLCOCOASPARTAMIDE p-PHENYLENEDIAMINE 24-DIAMINOPHENOXYETHANOL HCL m-AMINOPHENOL HYDROXYPROPYL BIS(N-HYDROXYETHYL-P-PHENYLENEDIAMINE) HCL AMMONIUM ACETATE AMMONIUM THIOLACTATE NN-BIS(2-HYDROXYETHYL)-p-PHENYLENEDIAMINE SULFATE RESORCINOL EDTA ERYTHORBIC ACID PARFUM / FRAGRANCE.Shine OilPPG-5-CETETH-20 HELIANTHUS ANNUUS SEED OIL / SUNFLOWER SEED OIL PARFUM / FRAGRANCE COCOS NUCIFERA OIL / COCONUT OIL TOCOPHEROL CAMELLIA OLEIFERA SEED OILPlease be aware that ingredient lists for the products of our brand are updated regularly. Please refer to the ingredient list on your product package for the most up to date list of ingredients to ensure it is suitable to your personal use.
How this analysis is generated
Each ingredient on this product's published label is matched against our 237 source-cited chemical rules, each documenting a concern from peer-reviewed research and regulatory sources. Severity tiers:
- Avoid (red) — banned or restricted in the EU, UK or Canada but still legal in the US, IARC-listed, or strong contact-allergen evidence.
- Caution (amber) — regulatory caution, contamination risk, or condition-specific irritant.
- Mild (green) — low concern but commonly avoided in low-tox formulations.
Each flag links to its primary chemical-level source, and each condition pill links to a PubMed-indexed paper that discusses the chemical class in the context of that condition. Every citation is a real peer-reviewed paper — we don't link to Wikipedia or PubMed search pages. Some pairs use a topically-broad paper (e.g. a fragrance-allergen patch-test review) rather than a single-pair study where the literature is thin. The full evidence chain (chemical → mechanism → condition → paper) is one click away.
This is automated analysis of a published label, not medical advice — always verify the label yourself before changing products. Methodology and source list at scan.lowtoxgear.com.