Print
Chemical Datasheet

BENZENE

3 - Flammable liquid

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 71-43-2   (BENZENE)
  • 1114
  • Flammable Liquid
  • BNZ
NIOSH Pocket Guide International Chem Safety Card
Benzene
  • BENZENE
NFPA 704
Diamond Hazard Value Description
3
2 0
Blue Health 2 Can cause temporary incapacitation or residual injury.
Red Flammability 3 Can be ignited under almost all ambient temperature conditions.
Yellow Instability 0 Normally stable, even under fire conditions.
White Special
(NFPA, 2010)
General Description
A clear colorless liquid with a petroleum-like odor. Flash point less than 0°F. Less dense than water and slightly soluble in water. Hence floats on water. Vapors are heavier than air.

Hazards

Reactivity Alerts
Air & Water Reactions
Highly flammable. Slightly soluble in water.
Fire Hazard
Behavior in Fire: Vapor is heavier than air and may travel considerable distance to a source of ignition and flash back. (USCG, 1999)
Health Hazard
Dizziness, excitation, pallor, followed by flushing, weakness, headache, breathlessness, chest constriction, nausea, and vomiting. Coma and possible death. (USCG, 1999)
Reactivity Profile
BENZENE reacts vigorously with allyl chloride or other alkyl halides even at -70°C in the presence of ethyl aluminum dichloride or ethyl aluminum sesquichloride. Explosions have been reported [NFPA 491M 1991]. Ignites in contact with powdered chromic anhydride [Mellor 11:235 1946-47]. Incompatible with oxidizing agents such as nitric acid. Mixtures with bromine trifluoride, bromine pentafluoride, iodine pentafluoride, iodine heptafluoride and other interhalogens can ignite upon heating [Bretherick 5th ed. 1995]. Benzene and cyanogen halides yield HCl as a byproduct (Hagedorn, F. H. Gelbke, and Federal Republic of Germany. 2002. Nitriles. In Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH Verlag GmbH & Co. KGaA.). The reaction of benzene and trichloroacetonitrile evolves toxic chloroform and HCl gases. (Hagedorn, F., H.-P. Gelbke, and Federal Republic of Germany. 2002. Nitriles. In Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH Verlag GmbH & Co. KGaA.).
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

No information available.

Response Recommendations

Isolation and Evacuation
Excerpt from 130 Polymerizable warning [Flammable Liquids (Water-Immiscible / Noxious)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 50 meters (150 feet) in all directions.

LARGE SPILL: Consider initial downwind evacuation for at least 300 meters (1000 feet).

FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2020)
Firefighting
Excerpt from 130 Polymerizable warning [Flammable Liquids (Water-Immiscible / Noxious)]:

CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient.

SMALL FIRE: Dry chemical, CO2, water spray or regular foam.

LARGE FIRE: Water spray, fog or regular foam. Avoid aiming straight or solid streams directly onto the product. If it can be done safely, move undamaged containers away from the area around the fire.

FIRE INVOLVING TANKS OR CAR/TRAILER LOADS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2020)
Non-Fire Response
Excerpt from 130 Polymerizable warning [Flammable Liquids (Water-Immiscible / Noxious)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. A vapor-suppressing foam may be used to reduce vapors. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. Use clean, non-sparking tools to collect absorbed material.

LARGE SPILL: Dike far ahead of liquid spill for later disposal. Water spray may reduce vapor, but may not prevent ignition in closed spaces. (ERG, 2020)
Protective Clothing
Excerpt from NIOSH Pocket Guide for Benzene:

Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact.

Wash skin: WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated.

Remove: WHEN WET (FLAMMABLE) - Work clothing that becomes wet should be immediately removed due to its flammability hazard (i.e., for liquids with a flash point <100°F).

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift.

Provide:
• EYEWASH - Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substances; this is irrespective of the recommendation involving the wearing of eye protection.
• QUICK DRENCH - Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (NIOSH, 2023)
DuPont Tychem® Suit Fabrics
Normalized Breakthrough Times (in Minutes)
Chemical CAS Number State QS QC SL C3 TF TP RC TK RF
Benzene 71-43-2 Liquid imm >480 >480 >480 >480 >480 >480
> indicates greater than.
"imm" indicates immediate; having a normalized breakthrough time of 10 minutes or less.

Special Warning from DuPont: Tychem® and Tyvek® fabrics should not be used around heat, flames, sparks or in potentially flammable or explosive environments. Only...

(DuPont, 2023)

First Aid
EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. Volatile chemicals have a high risk of being aspirated into the victim's lungs during vomiting which increases the medical problems. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. IMMEDIATELY transport the victim to a hospital. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital.

OTHER: Since this chemical is a known or suspected carcinogen you should contact a physician for advice regarding the possible long term health effects and potential recommendation for medical monitoring. Recommendations from the physician will depend upon the specific compound, its chemical, physical and toxicity properties, the exposure level, length of exposure, and the route of exposure. (NTP, 1992)

Physical Properties

Chemical Formula:
  • C6H6
Flash Point: 12°F (NTP, 1992)
Lower Explosive Limit (LEL): 1.4 % (NTP, 1992)
Upper Explosive Limit (UEL): 8 % (NTP, 1992)
Autoignition Temperature: 1097°F (USCG, 1999)
Melting Point: 41.9°F (NTP, 1992)
Vapor Pressure: 60 mmHg at 59°F ; 76 mmHg at 68°F (NTP, 1992)
Vapor Density (Relative to Air): 2.77 (NTP, 1992) - Heavier than air; will sink
Specific Gravity: 0.879 at 68°F (USCG, 1999) - Less dense than water; will float
Boiling Point: 176.2°F at 760 mmHg (NTP, 1992)
Molecular Weight: 78.11 (NTP, 1992)
Water Solubility: 1 to 5 mg/mL at 64°F (NTP, 1992)
Ionization Energy/Potential: 9.24 eV (NIOSH, 2023)
IDLH: 500 ppm ; A potential occupational carcinogen. (NIOSH, 2023)

AEGLs (Acute Exposure Guideline Levels)

Interim AEGLs for Benzene (71-43-2)
Exposure Period AEGL-1 AEGL-2 AEGL-3
10 minutes 130 ppm 2000 ppm 1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account. 9700 ppm 2-flame icon indicates value is 50-99% of LEL. Extreme safety consideration against explosions must be taken into account.
30 minutes 73 ppm 1100 ppm 5600 ppm 1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account.
60 minutes 52 ppm 800 ppm 4000 ppm 1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account.
4 hours 18 ppm 400 ppm 2000 ppm 1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account.
8 hours 9 ppm 200 ppm 990 ppm
Lower Explosive Limit (LEL) = 14000 ppm
1-flame icon indicates value is 10-49% of LEL. Safety consideration against explosions must be taken into account.
2-flame icon indicates value is 50-99% of LEL. Extreme safety consideration against explosions must be taken into account.
(NAC/NRC, 2023)

ERPGs (Emergency Response Planning Guidelines)

Chemical ERPG-1 ERPG-2 ERPG-3
Benzene (71-43-2) 50 ppm star-in-circle icon indicates that odor should be detectable near ERPG-1. 150 ppm 1000 ppm
star-in-circle icon indicates that odor should be detectable near ERPG-1.
(AIHA, 2022)

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Benzene (71-43-2) 52 ppm 800 ppm 4000 ppm 1-flame icon indicates value is 10-49% of LEL. LEL = 14000 ppm
1-flame icon indicates value is 10-49% of LEL.
(DOE, 2018)

Regulatory Information

EPA Consolidated List of Lists

Regulatory Name CAS Number/
313 Category Code
EPCRA 302
EHS TPQ
EPCRA 304
EHS RQ
CERCLA RQ EPCRA 313
TRI
RCRA
Code
CAA 112(r)
RMP TQ
Benzene ᵃ 71-43-2 10 pounds 313 U019

(EPA List of Lists, 2022)

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

No regulatory information available.

OSHA Process Safety Management (PSM) Standard List

No regulatory information available.

Alternate Chemical Names