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HYDROQUINONE
ICSC: 0166
Peer-Review Status: 15.10.2001 Validated
1,4-Dihydroxybenzene
Hydroquinol
Quinol 
CAS #: 123-31-9 RTECS #: MX3500000
UN #: 2662
EC #: 604-005-00-4
EINECS #: 204-617-8
    Formula: C6H6O2 / C6H4(OH)2
Molecular mass: 110.1

TYPES OF
HAZARD /
EXPOSURE
ACUTE HAZARDS / SYMPTOMS      PREVENTION      FIRST AID / FIRE FIGHTING
FIRE Combustible.  NO open flames.  Use water spray, powder, foam, carbon dioxide. 
EXPLOSION Finely dispersed particles form explosive mixtures in air.  Closed system, ventilation, explosion-proof electrical equipment and lighting. Prevent deposition of dust.   
 
EXPOSURE   PREVENT DISPERSION OF DUST! AVOID ALL CONTACT!   
Inhalation Cough. Laboured breathing.  Use local exhaust or breathing protection.  Fresh air, rest. Artificial respiration may be needed. Refer for medical attention. 
Skin Redness.  Protective gloves. Protective clothing.  Remove contaminated clothes. Rinse and then wash skin with water and soap. 
Eyes Redness. Pain. Blurred vision.  Wear safety goggles.  First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. 
Ingestion Dizziness. Headache. Nausea. Shortness of breath. Convulsions. Vomiting. Ringing in the ears.  Do not eat, drink, or smoke during work. Wash hands before eating.  Rinse mouth. Induce vomiting (ONLY IN CONSCIOUS PERSONS!). Refer for medical attention . 

SPILLAGE DISPOSAL
PACKAGING & LABELLING
Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Sweep spilled substance into covered sealable containers. Carefully collect remainder. Then store and dispose of according to local regulations.  Do not transport with food and feedstuffs. 
EC Classification
Symbol: Xn, N; R: 22-40-41-43-50-68; S: (2)-26-36/37/39-61 
UN Classification
UN Hazard Class: 6.1; UN Pack Group: III 
GHS Classification
 

EMERGENCY RESPONSE SAFE STORAGE
Transport Emergency Card: TEC (R)-61GT2-III.
NFPA Code: H2; F1; R0. 
Separated from strong bases and food and feedstuffs. 

IMPORTANT DATA
Physical State; Appearance
COLOURLESS CRYSTALS. 

Physical dangers
Dust explosion possible if in powder or granular form, mixed with air. 

Chemical dangers
Reacts violently with sodium hydroxide. 

Occupational exposure limits
TLV: 2mg/m³ as TWA; A3 (confirmed animal carcinogen with unknown relevance to humans); (ACGIH 2004).
MAK: Carcinogen category: 2; Germ cell mutagen group: 3A; Skin absorption (H); Sensitization of skin (SH); (DFG 2007). 

Routes of exposure
The substance can be absorbed into the body by inhalation, through the skin and by ingestion. 

Inhalation risk
A harmful contamination of the air will not or will only very slowly be reached on evaporation of this substance at 20°C. 

Effects of short-term exposure
The substance is severely irritating to the eyes. The substance is irritating to the skin and respiratory tract. 

Effects of long-term or repeated exposure
Repeated or prolonged contact with skin may cause dermatitis. Repeated or prolonged contact may cause skin sensitization. The substance may have effects on the eyes and skin. This may result in discolouration of the conjunctiva and cornea and skin depigmentation. This substance is possibly carcinogenic to humans. 


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
Boiling point: 287°C
Melting point: 172°C
Relative density (water = 1): 1.3
Solubility in water, g/100ml at 15°C: 5.9
Vapour pressure, Pa at 20°C: 0.12
Relative vapour density (air = 1): 3.8
Relative density of the vapour/air-mixture at 20°C (air = 1): 1
Flash point: 165°C
Auto-ignition temperature: 515°C
Octanol/water partition coefficient as log Pow: 0.59  
The substance is very toxic to aquatic organisms. 

NOTES
Depending on the degree of exposure, periodic medical examination is suggested.
No odour warning if toxic concentrations are present.
Black & White Bleaching Cream, Diak 5, Eldopaque, Eldoquin, Tecquinol, Tenox HQ are trade names.
Card has been partly updated in April 2005.
See sections Occupational Exposure Limits, EU classification, Emergency Response. 

ADDITIONAL INFORMATION
 

IPCS
International
Programme on
Chemical Safety
WHO ILO EC Prepared in the context of cooperation between the International Programme on Chemical Safety and the European Commission
© IPCS 2004-2012
LEGAL NOTICE Neither the EC nor the IPCS nor any person acting on behalf of the EC or the IPCS is responsible for the use which might be made of this information.
    See Also:
       Toxicological Abbreviations
       Hydroquinone (EHC 157, 1994)
       Hydroquinone (HSG 101, 1996)
       Hydroquinone  (SIDS)
       Hydroquinone (IARC Summary & Evaluation, Volume 71, 1999)