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p-BENZOQUINONEICSC: 0779
2,5-Cyclohexadiene-1,4-dione
Quinone
1,4-Benzoquinone
p-Quinone
October 1997
CAS #: 106-51-4
UN #: 2587
EC Number: 203-405-2

  ACUTE HAZARDS PREVENTION FIRE FIGHTING
FIRE & EXPLOSION Flammable. Gives off irritating or toxic fumes (or gases) in a fire.  Above 38°C explosive vapour/air mixtures may be formed. Finely dispersed particles form explosive mixtures in air.  NO open flames, NO sparks and NO smoking.  Closed system, dust explosion-proof electrical equipment and lighting. Prevent deposition of dust. Prevent build-up of electrostatic charges (e.g., by grounding).  Use water spray, powder, carbon dioxide.  In case of fire: keep drums, etc., cool by spraying with water. 

 PREVENT DISPERSION OF DUST! STRICT HYGIENE! IN ALL CASES CONSULT A DOCTOR! 
  SYMPTOMS PREVENTION FIRST AID
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 CLASSIFICATION & 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. 

According to UN GHS Criteria

 

Transportation
UN Classification
UN Hazard Class: 6.1; UN Pack Group: II 

STORAGE
Fireproof. Separated from combustible substances, reducing agents and food and feedstuffs. Cool. Dry. 
PACKAGING
Do not transport with food and feedstuffs. 
p-BENZOQUINONE ICSC: 0779
PHYSICAL & CHEMICAL INFORMATION

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. 

Formula: C6H4O2
Molecular mass: 108.1
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  


EXPOSURE & HEALTH EFFECTS

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

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. 

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

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. 


OCCUPATIONAL EXPOSURE LIMITS
TLV: 0.1 ppm as TWA.
MAK: sensitization of skin (SH); carcinogen category: 3B; germ cell mutagen group: 3B 

ENVIRONMENT
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. 

ADDITIONAL INFORMATION
  EC Classification
Symbol: T, N; R: 23/25-36/37/38-50; S: (1/2)-26-28-45-61 

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       Toxicological Abbreviations