- beauty
- industrial
- pharma
Hydroquinone
CAS 123-31-9 · 100/100 · High conf.
Also registered as 2 other CAS numbers
8027-02-9 · 57534-13-1
Concern score
100/100Critical concern driven by cmr.
High confidence
Hydroquinone in plain language
Also known as Benzene-1,4-diol · 1,4-Benzenediol · 1,4-Benzoquinol · 1,4-Dihydroxybenzene · 4-Hydroxyphenol · Arctuvin
Show all 31 names
Benzene, 1,4-DIHYDROXY- · Black and white bleaching cream · Benzohydroquinone · Benzoquinol · Dihydroxybenzene · Eldopaque forte · Eldoquin forte · Eldopaque · Eldoquin · Hydroquinole · Idrochinone · NCI-C55834 · Phiaquin · Quinol · Solaquin forte · Tecquinol · hydroquinol · hydroquinone (sara 302/313) (cercla) · hydroquinone (sara iii) · p-Benzenediol · p-Dihydroxybenzene · p-Dioxybenzene · p-Hydroquinone · p-Hydroxyphenol · Tri-luma component hydroquinone
Used in cosmetics as an antioxidant, a bleaching agent and a hair dye. Hydroquinone is the aromatic organic compound.
- Antioxidant
- Bleaching
- Hair dyeing
- Reducing
- Fragrance
- Colourant
- Critical concern: classified for carcinogenic, mutagenic or reproductive toxicity (CMR). It is banned in EU cosmetics and restricted in Canadian cosmetics.
Why it's flagged
- Cmr
1,4-Dihydroxybenzene (Hydroquinone), with the exception of entry 14 in Annex III is prohibited in cosmetic products under Annex II of the EU Cosmetics Regulation (EC) 1223/2009.
RestrictedCA Health Canada — Restricted · EU EC — restricted · EU EC — banned
The score describes this ingredient's chemical identity — its hazard profile from published classifications and regulatory status — not the safety of any product it appears in.
Regulation
Restrictions first, then routine listings from published regulatory sources.
- In marketed US drugs
- EU Annex II — prohibited
- EU Annex III — restricted
- EU prohibited in cosmetics
- EU restricted in cosmetics
- Found in consumer products
- Pharma
- Industrial
- View source →Restricted
CAHealth Canada
Restricted by the Health Canada Cosmetic Ingredient Hotlist for cosmetics.
- View source →restricted
EUEC
Annex III of EU Cosmetics Regulation (EC) 1223/2009: substances which cosmetic products must not contain except subject to the restrictions laid down. Product types: Artificial nail systems Maximum concentration: 0.02% (after mixing for use) Other conditions: Professional use Conditions of use and warnings: - For professional use only - Avoid skin contact - Read directions for use carefully CMR: Carcinogenic Cat. 2(),Mutagenic Cat. 2()
- View source →banned
EUEC
Annex II of EU Cosmetics Regulation (EC) 1223/2009: substances prohibited in cosmetic products. CMR: Carcinogenic Cat. 2(),Mutagenic Cat. 2()
USEPAcommercial use observedEPA CPDat observed this chemical in 1954 composition records across product categories including Cons. electronics, mech. appliances, and machinery, Laboratory supplies, Specialty occupational products. EPA CPDat classifies this chemical for functional uses including Stabilizing agent, Antioxidant, Fragrance.
- EPA CPDat observed this chemical in 1954 composition records across product categories including Cons. electronics, mech. appliances, and machinery, Laboratory supplies, Specialty occupational products. EPA CPDat classifies this chemical for functional uses including Stabilizing agent, Antioxidant, Fragrance.Source →
USFDAmarketed drug occurrenceFDA NDC lists this ingredient in 20 active drug products and 22 total products.
- FDA NDC lists this ingredient in 20 active drug products and 22 total products.Source →
USFDAlisted in openFDA substanceopenFDA substance registry classifies this ingredient as chemical.
- openFDA substance registry classifies this ingredient as chemical.Source →
Expert safety opinions
No expert opinion on file for Hydroquinone. These are the independent scientific bodies that assess ingredients like this one; we show an opinion only when a record we hold cites it.
SCCS
EU Scientific Committee on Consumer Safety
No SCCS opinion on file.
CIR
Cosmetic Ingredient Review (US expert panel)
No CIR safety assessment on file.
Evidence & sources
No graded research studies for Hydroquinone yet. This record is compiled from the published data sources below — registries and regulatory listings, not study findings.
Where this comes from
- Open →
CosIng
regulatory · updated 2026-09-23
- Open →
EU CosIng Cosmetics Regulation Annexes
regulatory · updated 2013-05-07
- Open →
EPA Chemical and Products Database
exposure · updated may 11, 2016
- Open →
EPA DSSTox Identifiers
chemistry · updated 2025-12-29
- Open →
FDA National Drug Code Directory
regulatory · updated 2027-12-31
- Open →
FDA GSRS UNII
registry · updated 2026-02-26
- Open →
Health Canada Cosmetic Ingredient Hotlist
regulatory · updated 2026-03-27
- Open →
openFDA Substance
registry · updated 2026-05-24
- Open →
PubChem Live Enrichment
chemistry · updated 2026-05-17
Reference links (2)
ebi.ac.uk
Allergen profile
Canonical allergen markers detected on this ingredient. Each row is derived from the ingredient’s name or synonyms matching a known allergen class — useful when scanning a label for a specific allergy context.
- DairyContains · Oral (ingested)
Source: chemindex_name_match
Suitability
Context-specific fit derived from published classifications and the current ingredient evidence profile.
Fragrance avoidance
Not a strong fit for fragrance avoidance because it carries Fragrance.
The ingredient itself is a fragrance-linked signal, so it is better treated as an avoid case when fragrance exposure is the main concern.
Where it has been recorded
How often EPA CPDat has listed Hydroquinone in a product composition. These are source records, not Greenveil catalog products.
Source records
1,954
Named organisations
6
Cons. electronics, mech. appliances, and machineryLaboratory suppliesSpecialty occupational productsMedical/dentalBatteriesIndustrial products
Typical roles
AntioxidantBleachingHair dyeingReducingFragranceColourant
Found in these products
Cosmetic and personal-care products that list Hydroquinone are shown first. Their ingredient lists include Hydroquinone; each product's own rating depends on its whole formula, so it is shown on the product page, not here.
