TIME-WEIGHTED AVERAGE (TLV-TWA): 0.5 ppm - Carcinogenicity Designation A1 - Skin

STEL: 2.5 ppm

TLV BASIS - CRITICAL EFFECT(S) : Cancer

CARCINOGENICITY DESIGNATION A1 - Confirmed Human Carcinogen: Substance is carcinogenic to humans based on convincing evidence from human studies. For a substance assigned a TLV, exposure should be controlled to levels as low as reasonably achievable below the TLV. Workers exposed to a substance without an assigned TLV should be properly equipped to eliminate virtually all exposure to it.

"SKIN" NOTATION: Contact with skin, eyes, and mucous membranes can contribute to the overall exposure and may invalidate the TLV. Consider measures to prevent absorption by these routes.

BIOLOGICAL EXPOSURE INDICES (BEIs): The ACGIH has adopted a BEI for this chemical. BEIs provide an indication of worker exposure by measuring the chemical or its breakdown products in the body or by measuring biochemical changes resulting from exposure to the chemical. Consult the BEI documentation for further information.

NOTE: This is a substance for which the TLV is higher than the OSHA Permissible Exposure Limit (PEL) and/or the NIOSH Recommended Exposure Limit (REL).

NOTE: This substance has been identified by other sources as a suspect or confirmed human carcinogen.

NOTE: In many Canadian jurisdictions, exposure limits are similar to the ACGIH TLVs. Since the manner in which exposure limits are established, interpreted, and implemented can vary, obtain detailed information from the appropriate government agency in each jurisdiction.

Extremely flammable liquid. Vapours can readily ignite at room temperature. Liquid can accumulate static charge by flow or agitation. Vapour can be ignited by a static discharge. Vapour is heavier than air and may travel a considerable distance to a source of ignition and flash back to a leak or open container. Liquid can float on water and may travel to distant locations and/or spread fire. During a fire, irritating/toxic gases may be generated. benzene can accumulate in confined spaces, resulting in a toxicity and flammability hazard. Containers may explode in heat of fire.

Benzene is normally stable.

Static charge, sparks, open flames, heat and other ignition sources.

61 ppm (detection); 97 ppm (recognition). Reported values range from 0.78-160 ppm.

POOR - Odour threshold is above the TLV.

This material is EXTREMELY FLAMMABLE and VERY TOXIC (CANCER HAZARD). Before handling, it is extremely important that engineering controls are operating and that protective equipment requirements and personal hygiene measures are being followed. Whenever possible, closed handling systems for processes involving this material should be used. Only authorized personnel should have access to this material. They should be properly trained regarding its hazards and its safe use. Maintenance and emergency personnel should be advised of potential hazards.

If benzene is released, immediately put on a suitable respirator and leave the area until the severity of the release is determined. Immediately report leaks, spills or ventilation failures. Have suitable emergency equipment for fires, spills and leaks readily available. Be aware of typical signs and symptoms of poisoning and first aid procedures. Any signs of illness should be reported immediately to supervisory personnel.

Eliminate all ignition sources, (e.g. sparks, open flames, hot surfaces). Keep away from heat. Post "NO SMOKING" signs. It is very important to keep areas where this material is used clear of other materials which can burn. Use non-sparking ventilation systems, approved explosion-proof equipment and intrinsically safe electrical systems in areas of use. Keep aisles and exits free of obstruction.

Use in smallest possible amounts in appropriate labelled, containment deices (fume hood, glove box, safety cabinets, isolation cabinets). Containment devices should be made of smooth, unbreakable, compatible material. Maintain containment devices at appropriate air flow and negative pressure. Check regularly. Use benzene in a well ventilated area separate from the storage area. Do not use with incompatible materials such as sodium peroxide, potassium peroxide and many other chemicals. Contact with these materials could lead to vigorous, violent reactions with fire and explosion.

Avoid generating vapours or mists. Prevent the release of vapours and mists into the workplace air. To avoid splashing, carefully dispense into sturdy containers made of compatible materials. Never transfer liquids by pressurizing the original shipping containers with air or inert gas.

Attach appropriate warning signs to laboratory entrance, storage area and to containment devices. Use in clearly labelled, designated area(s). Control access to designated area. Access doors must remain closed while this material is present. Keep a record of acquisition date, opening date and quantity used. Cover work surfaces with compatible, chemical resistant and/or disposable material for easier containment and clean-up of spills. Keeping work areas clean is essential. Use work surfaces that can be easily decontaminated. Do not contaminate air or water systems with this material when used in conjunction with vacuum devices. Protect vacuum lines. Use separate vacuum pump inside or vented into appropriate chemical hood. If possible, air flow in laboratory should move from area of lower contamination potential to area of higher contamination potential. Maintain good personal hygiene.

Do not dispense in storage area unless dispensing area is segregated by fire-resistant construction. Only use portable containers and dispensing equipment (faucet, pump, drip can) approved for flammable liquids. Electrically ground all drums, transfer vessels, hoses and piping. Ground clips must contact bare metal. When dispensing in other than a closed system, ensure dispensing container is bonded to receiving transfer equipment and container. Liquid can accumulate charge. Increase conductivity with additive designed for that purpose, reduce flowrate in transfer operations, increase time the liquid remains in transfer piping and/or handle at lower temperature. Never return contaminated material to its original container. To reduce the fire/explosion hazard, consider the use of an inert gas in the container or storage vessel. For large scale operations, consider the installation of leak and fire detection equipment along with a suitable, automatic fire suppression system.

Label containers. Open containers carefully on a stable surface. Keep them closed when not in use. Avoid damaging them. Assume that empty containers contain hazardous residues. Never perform any welding, cutting, soldering, drilling or other hot work on an empty vessel, container or piping until all liquid and vapours have been cleared.

Follow handling precautions on Material Safety Data Sheet. Have suitable emergency equipment for fires, spills and leaks readily available. Practice good housekeeping. Maintain handling equipment. Comply with applicable regulations.

Engineering control methods to reduce hazardous exposures are preferred. Methods include mechanical ventilation (dilution and local exhaust), process or personnel enclosure, control of process conditions, and process modification (e.g., substitution of a less hazardous material). Administrative controls and personal protective equipment may also be required. Because of the high potential hazard associated with this substance, stringent control measures such as enclosure or isolation may be necessary. Use a non-sparking, grounded ventilation system separate from other exhaust ventilation systems. Exhaust directly to the outside. Supply sufficient replacement air to make up for air removed by exhaust systems.