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p-BENZOQUINONE
ICSC: 0779
Peer-Review Status: 10.10.1997 Validated
2,5-Cyclohexadiene-1,4-dione
Quinone
1,4-Benzoquinone
p-Quinone 
CAS #: 106-51-4 RTECS #: DK2625000
UN #: 2587
EC #: 606-013-00-3
EINECS #: 203-405-2
    Formula: C6H4O2
Molecular mass: 108.1

TYPES OF
HAZARD /
EXPOSURE
ACUTE HAZARDS / SYMPTOMS      PREVENTION      FIRST AID / FIRE FIGHTING
FIRE Flammable. Gives off irritating or toxic fumes (or gases) in a fire.  NO open flames, NO sparks and NO smoking.  Use water spray, powder, carbon dioxide. 
EXPLOSION Above 38°C explosive vapour/air mixtures may be formed. Finely dispersed particles form explosive mixtures in air.  Closed system, ventilation, explosion-proof electrical equipment and lighting. Prevent deposition of dust. Prevent build-up of electrostatic charges (e.g., by grounding).  In case of fire: keep drums, etc., cool by spraying with water. 
 
EXPOSURE   PREVENT DISPERSION OF DUST! STRICT HYGIENE!  IN ALL CASES CONSULT A DOCTOR! 
Inhalation Burning sensation. Cough. Laboured breathing. Shortness of breath. Sore throat.  Use local exhaust or breathing protection.  Fresh air, rest. Half-upright position. Refer for medical attention. 
Skin Redness. Pain. Skin discoloration. Blisters.  Protective gloves. Protective clothing.  Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer for medical attention . 
Eyes Redness. Pain. Blurred vision. Brown staining.  Wear safety spectacles, face shield or eye protection in combination with breathing protection.  First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. 
Ingestion Abdominal pain. Burning sensation. Diarrhoea. Vomiting.  Do not eat, drink, or smoke during work. Wash hands before eating.  Rinse mouth. Give a slurry of activated charcoal in water to drink. Do NOT induce vomiting. 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 containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.  Do not transport with food and feedstuffs. 
EC Classification
Symbol: T, N; R: 23/25-36/37/38-50; S: (1/2)-26-28-45-61 
UN Classification
UN Hazard Class: 6.1; UN Pack Group: II 
GHS Classification
 

EMERGENCY RESPONSE SAFE STORAGE
Transport Emergency Card: TEC (R)-61GT2-II.
NFPA Code: H1; F2; R1. 
Fireproof. Separated from combustible substances, reducing agents and food and feedstuffs. Cool. Dry. 

IMPORTANT DATA
Physical State; Appearance
YELLOW CRYSTALS WITH PUNGENT ODOUR. CAN SUBLIME EVEN AT ROOM TEMPERATURE. 

Physical dangers
Dust explosion possible if in powder or granular form, mixed with air. If dry, it can be charged electrostatically by swirling, pneumatic transport, pouring, etc. 

Chemical dangers
Decomposes above 60°C when moist. This produces carbon monoxide. The substance is a weak oxidant. It reacts violently with some combustible substances, reducing agents and strong bases. 

Occupational exposure limits
TLV: 0.1ppm as TWA; (ACGIH 2004).
MAK: Carcinogen category: 3B; Germ cell mutagen group: 3B; Sensitization of skin (SH); (DFG 2004). 

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

Inhalation risk
A harmful contamination of the air can be reached rather quickly on evaporation of this substance at 20°C. 

Effects of short-term exposure
The substance is irritating to the eyes, skin and respiratory tract. The substance may cause effects on the eyes. Exposure far above the OEL could cause respiratory failure and death. 

Effects of long-term or repeated exposure
Repeated or prolonged contact with skin may cause dermatitis. The substance may have effects on the skin and eyes. This may result in discolouration; inflammation and injury of the corneal epithelium. 


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
Boiling point: ~180°C
Melting point: 116°C
Solubility in water: poor
Vapour pressure, Pa at 20°C: 12
Relative vapour density (air = 1): 3.7
Relative density of the vapour/air-mixture at 20°C (air = 1): 1.0
Flash point: 38-93°C
See Notes.
Auto-ignition temperature: 560°C
Octanol/water partition coefficient as log Pow: 0.2  
The substance is very toxic to aquatic organisms. 

NOTES
Physical properties (e.g. flash point) depend largely on humidity.
The odour warning when the exposure limit value is exceeded is insufficient.
Card has been partly updated in October 2004.
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