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p-BENZOQUINONE ICSC: 0779
Date of Peer Review: October 1997

2,5-Cyclohexadiene-1,4-dione
Quinone
1,4-Benzoquinone
p-Quinone
CAS # 106-51-4 C6H4O2
RTECS # DK2625000 Molecular mass: 108.1
UN # 2587
EC Index # 606-013-00-3
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.
Water spray, powder, carbon dioxide.
EXPLOSION Above 38C explosive vapour/air mixtures may be formed. Finely dispersed particles form explosive mixtures in air.
Prevent deposition of dust; closed system, dust explosion-proof electrical equipment and lighting. 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.
Local exhaust or breathing protection.
Fresh air, rest. Half-upright position. Refer for medical attention.
Skin Redness. Pain. Discolouration. 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.
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 take to a doctor.
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
Sweep spilled substance into containers; if appropriate, moisten first to prevent dusting. Carefully collect remainder, then remove to safe place. Do NOT let this chemical enter the environment. Personal protection: P3 filter respirator for toxic particles.
Do not transport with food and feedstuffs.
EU 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
EMERGENCY RESPONSE STORAGE
Transport Emergency Card: TEC (R)-61GT2-II
NFPA Code: H1; F2; R1;
Fireproof. Separated from combustible and reducing substances, food and feedstuffs. Cool. Dry.
IPCS
International
Programme on
Chemical Safety
Prepared in the context of cooperation between the International Programme on Chemical Safety and the Commission of the European Communities IPCS, CEC 2005

SEE IMPORTANT INFORMATION ON BACK
p-BENZOQUINONE ICSC: 0779
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:
The substance decomposes on warming above 60C, when moist, producing carbon monoxide. Reacts as a weak oxidant violently with some combustible substances, reducing agents and strong bases.

OCCUPATIONAL EXPOSURE LIMITS:
TLV: 0.1 ppm as TWA (ACGIH 2004).
MAK: Sh Carcinogen category: 3B; Germ cell mutagen group: 3B; (DFG 2004).
ROUTES OF EXPOSURE:
The substance can be absorbed into the body by inhalation, by ingestion.

INHALATION RISK:
A harmful contamination of the air can be reached rather quickly on evaporation of this substance at 20C.

EFFECTS OF SHORT-TERM EXPOSURE:
The substance irritates the eyes, the skin and the respiratory tract. The substance may cause effects on the eyes. Exposure far above the OEL may result in 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, resulting in discolouration, inflammation and injury of the corneal epithelium.
PHYSICAL PROPERTIES
Boiling point: ca. 180C
Melting point: 116C
Solubility in water: poor
Vapour pressure, Pa at 20C: 12
Relative vapour density (air = 1): 3.7
Relative density of the vapour/air-mixture at 20C (air = 1): 1.0
Flash point: (see Notes) 38-93C
Auto-ignition temperature: 560C
Octanol/water partition coefficient as log Pow: 0.2
ENVIRONMENTAL DATA
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


LEGAL NOTICE Neither the CEC nor the IPCS nor any person acting on behalf of the CEC or the IPCS is responsible for the use which might be made of this information
IPCS, CEC 2005