Hydroquinone

Hydroquinone
	Hydroquinone
Names
	Preferred IUPAC name Benzene-1,4-diol
	Other names Hydroquinone; Idrochinone; Quinol; 4-Hydroxyphenol; 1,4-Dihydroxybenzene; p-Dihydroxybenzene; p-Benzenediol
Identifiers
CAS Number	123-31-9 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	605970
ChEBI	CHEBI:17594 ;
ChEMBL	ChEMBL537 ;
ChemSpider	764 ;
DrugBank	DB09526;
ECHA InfoCard	100.004.199
EC Number	204-617-8;
Gmelin Reference	2742
KEGG	D00073 ;
PubChem CID	785;
RTECS number	MX3500000;
UNII	XV74C1N1AE ;
UN number	3077, 2662
CompTox Dashboard (EPA)	DTXSID7020716 ;
	InChI InChI=1S/C6H6O2/c7-5-1-2-6(8)4-3-5/h1-4,7-8H Key: QIGBRXMKCJKVMJ-UHFFFAOYSA-N ; InChI=1/C6H6O2/c7-5-1-2-6(8)4-3-5/h1-4,7-8H Key: QIGBRXMKCJKVMJ-UHFFFAOYAX;
	SMILES c1cc(ccc1O)O;
Properties
Chemical formula	C6H6O2
Molar mass	110.112 g·mol−1
Appearance	White solid
Density	1.3 g cm−3, solid
Melting point	172 °C (342 °F; 445 K)
Boiling point	287 °C (549 °F; 560 K)
Solubility in water	5.9 g/100 mL (15 °C)
Vapor pressure	10−5 mmHg (20 °C)
Acidity (pKa)	9.9
Magnetic susceptibility (χ)	−64.63×10−6 cm3/mol
Structure
Dipole moment	1.4±0.1 D
Pharmacology
ATC code	D11AX11 (WHO)
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H317, H318, H341, H351, H400
Precautionary statements	P201, P202, P261, P264, P270, P272, P273, P280, P281, P301+P312, P302+P352, P305+P351+P338, P308+P313, P310, P321, P330, P333+P313, P363, P391, P405, P501
NFPA 704 (fire diamond)	2 1
Flash point	165 °C (329 °F; 438 K)
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	490 mg/kg (mammal, oral); 245 mg/kg (mouse, oral); 200 mg/kg (rabbit, oral); 320 mg/kg (rat, oral); 550 mg/kg (guinea pig, oral); 200 mg/kg (dog, oral); 70 mg/kg (cat, oral)
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 2 mg/m3
REL (Recommended)	C 2 mg/m3 [15-minute]
IDLH (Immediate danger)	50 mg/m3
Related compounds
Related benzenediols	Pyrocatechol; Resorcinol
Related compounds	1,4-benzoquinone
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Hydroquinone, also known as benzene-1,4-diol or quinol, is an aromatic organic compound that is a type of phenol, a derivative of benzene, having the chemical formula C₆H₄(OH)₂. It has two hydroxyl groups bonded to a benzene ring in a para position. It is a white granular solid. Substituted derivatives of this parent compound are also referred to as hydroquinones. The name "hydroquinone" was coined by Friedrich Wöhler in 1843.