Pyrogallol is a benzenetriol carrying hydroxy groups at positions 1, 2 and 3.
Definition
Pyrogallol is a benzenetriol carrying hydroxy groups at positions 1, 2 and 3. It has a role as a plant metabolite. It is a phenolic donor and a benzenetriol.
Source: PubChem
US FDA substance register · UNII 01Y4A2QXY0 · registered name PYROGALLOL · single chemical substance
Cosmetic roles
Safety & regulatory references
- Banned
- ASEAN · Canada · China · European Union · Japan · South Korea · Taiwan · United Kingdom
- Allowed colourant
- United States
Source: ASEAN Cosmetic Directive · EU Cosmetics Regulation · Health Canada Cosmetic Ingredient Hotlist · Japan Standards for Cosmetics · MFDS (Korea) cosmetic regulatory information · Taiwan FDA cosmetic ingredients · UK cosmetics regulations (OPSS) · US FDA color additives · US FDA prohibited and restricted ingredients
Not classified under Korea’s toxic-substance GHS list · existing chemical substance
EU Cosmetics Regulation, Annex II (prohibited substances), entry 409
Health Canada Cosmetic Ingredient Hotlist · prohibited in cosmetics
Restriction II/409 · Other restriction: ban substances that deplete the ozone layer
Source: EU CosIng ingredient list
Reviewed by CIR: Final Report on the Safety Assessment of Pyrogallol
Reviewed by CIR: Tentative Report: Amended Safety Assessment of Pyrogallol as Used in Cosmetics
Reviewed by CIR: Re-evaluation: Pyrogallol
More data — names, identifiers, properties, test records, literature
Names & identifiers
- CAS No.chemical registry number
- 87-66-1
- DTXSIDUS EPA chemical ID
- DTXSID6025983
- DTXCIDUS EPA compound ID
- DTXCID905983
- IUPAC
- Benzene-1,2,3-triol
- Molecular formula
- C6H6O3
- Molecular weight
- 126.111 g/mol
Measured properties
- Appearance
- Pyrogallic acid is an odorless white to gray solid. Sinks and mixes with water. (USCG, 1999) · Dry Powder
- Odour
- Odorless · almost odourless
- Boiling point
- 588 °F at 760 mmHg (Decomposes at 559 °F) (NTP, 1992) · 309 °C
- Melting point
- 271 to 273 °F (NTP, 1992) · 133 °C
- Solubility
- greater than or equal to 100 mg/mL at 77 °F (NTP, 1992) · Very soluble in ethanol, diethyl ether
- Density
- 1.45 at 68 °F (USCG, 1999) - Denser than water, will sink · 1.453 g/cu cm at 4 °C
- Stability
- BECOMES GRAYISH ON EXPOSURE TO AIR & LIGHT, AQ SOLN DARKENS ON EXPOSURE TO AIR, QUITE RAPIDLY WHEN ALKALINE
- Dissociation constant
- pKa = 9.01
- Colour
- white
- Melting/freezing point
- 131~134 ℃
- Initial boiling point and range
- 309 ℃
- Flash point
- 164 ℃
- Upper/lower flammability or explosive limits
- 10.8 / 1.7 %
- Vapour pressure
- 1.33 ㎪ (168℃)
- Water solubility
- 60 g/100g (20℃)
- Relative density
- 1.45
- n-Octanol/water partition coefficient (Kow)
- 0.970 (est.)
- Molecular weight
- 126.11
Values measured on the substance itself. The KOSHA data are a reference for writing and reviewing safety data sheets, not a specification for a commercial raw material.
Source: PubChem · KOSHA safety data sheets (Korea)
What products actually use it for
What the 2 products reported to the US EPA with this ingredient use it for. Products outside cosmetics are included, so the top few rows are its main uses.
- Dye2
Source: US EPA CompTox dashboard
Irritation and sensitisation studies
2 skin studies and 2 eye studies are on record.
The study conclusions largely agree (100%). These tests are on the raw material itself; irritation at the amount in a finished product is a different question.
See all 4 studies
- Classification not possible
Skin Sensitization · Screening - Not classified
Skin Irritation · Screening - Serious eye damage/eye irritation - Category 2
Eye Irritation · Screening - Category 2
Eye Irritation · Screening
Source: US EPA CompTox dashboard
Related literature
- Pyrogallol loaded chitosan-based polymeric hydrogel for controlling Acinetobacter baumannii wound infections: Synthesis, characterization, and topical application. · 2024
- Exposure to pyrogallol impacts the hemato-biochemical endpoints in catfish (Clarias gariepinus). · 2023
- Analytical Method Development and Dermal Absorption of Pyrogallol, a Hair Dye Ingredient · 2022
- A tough, adhesive, self-healable, and antibacterial plant-inspired hydrogel based on pyrogallol-borax dynamic cross-linking. · 2021
- Toxicology and carcinogenesis studies of pyrogallol (CAS No. 87-66-1) in F344/N rats and B6C3F1/N mice (dermal studies). · 2013
Linked databases 29
- ASEAN Cosmetic Directive
- Australian Industrial Chemicals Inventory (AICIS)
- ChEBI
- ChEMBL
- EU CosIng ingredient list 2
- EU Cosmetics Regulation
- EU prohibited substances (Annex II)
- Health Canada Cosmetic Ingredient Hotlist
- Japan Standards for Cosmetics
- Korea toxic substances GHS register (NIER)
- KOSHA safety data sheets (Korea)
- MFDS (Korea) cosmetic ingredient register 2
- MFDS (Korea) cosmetic regulatory information 2 3
- NIST Chemistry WebBook
- PubChem 2
- Taiwan FDA cosmetic ingredients
- Tlooto literature search 2 3 4 5
- UK cosmetics regulations (OPSS)
- UniChem cross-reference IDs
- US Cosmetic Ingredient Review (CIR) 2 3 4
- US EPA CompTox dashboard 2
- US EPA DSSTox chemical database
- US FDA color additives
- US FDA prohibited and restricted ingredients
- US FDA substance registration (GSRS)
- US FDA Unique Ingredient Identifier (UNII)
- US National Toxicology Program reports
- Wikidata
- Wikipedia · Korean · English · Japanese · Chinese