Benzene

Hazard Overview

What is benzene?

Benzene is the simplest of a group of hydrocarbon compounds known as aromatic hydrocarbons and has the molecular formula C₆H₆. Aromatic hydrocarbons such as benzene have a circular structure that allows electrons known as pi electrons to be delocalized (or “shared”) among all the carbon atoms.

What are some common uses of benzene?

Although benzene is a common impurity in gasoline from the refining of crude oil [and from coal tar], benzene is most commonly produced using manufacturing processes. Benzene has a diverse application in industry where it is used as a solvent, a chemical intermediate, and a constituent in motor fuels.

The United States produced 5,155 metric tons of benzene in 2017. Refineries produce benzene as a by-product of gasoline production and account for around 60% of US benzene production.

What are the hazards associated with benzene?

Physical hazards associated with the use of benzene arise from its flammability. Benzene, which has a boiling point of 176.2 deg. F, is a Category 2 flammable liquid with a flash point of 12.2 deg. F and lower and upper explosion limits of 1.3% and 8% by volume, respectively. Additional information about the physical properties and sampling method(s) for benzene, as well as a summary of exposure limits, can be found on the OSHA Occupational Chemical Database.

Health hazards associated with benzene include skin and eye irritation, neurological symptoms, and it can affect the bone marrow, resulting in aplastic anemia. However, the predominant health effect associated with exposure to benzene is the development of cancer, in particular acute myeloid leukemia (AML).

Solutions

What can I do to protect myself and others?

Engineering and Work Practice Controls. When possible, substitute less hazardous chemicals for benzene. Work involving the use of benzene should be conducted in well-ventilated areas and away from ignition sources.

Personal Protective Equipment (PPE). When substitution is not feasible and engineering controls are not adequate to maintain airborne exposures below the permissible exposure limit (PEL) for benzene, appropriate respiratory protection must be used in conjunction with an effective respiratory protection program. In addition, appropriate skin protection and hand protection, such as chemical resistant gloves, should be worn when contact with benzene is reasonably anticipated.

What resources are available to assist employers?

• Presentations on a variety of topics associated with the use of benzene are available to assist employers in training their staff. These include: hazard communication; respiratory protection; and personal protective equipment. Each of these presentations should be modified to address site-specific conditions and hazards. A list of additional presentations, with hyperlinks, can be found on the NCDOL website at OSH Presentations.  

• Example safety and health programs are available are available for employers to download and adapt to their specific conditions. Safety and health programs relative to benzene include: hazard communication program; personal protective equipment program; hazardous chemical program, and respiratory protection program.

More information related to benzene can be found on the A-Z topics pages for flammable liquids, hazard communication, personal protective equipment, and respiratory protection. In addition, the NCDOL Library offers free safety and health videos and related research assistance on consensus standards (i.e., ANSI, NFPA, NEC). The education, training and technical assistance bureau provides free online safety and health training and outreach services (i.e., speaker's bureau requests, safety booths) upon request. Lastly, the consultative services bureau provides free and confidential onsite consultation regarding worksite safety and health hazards.

Regulations

Which standards apply?

The OSH Division has adopted the following standards which are applicable to occupational exposure to benzene in North Carolina:

General Industry

• 29 CFR 1910 Subpart G - occupational and environmental controls

  • 29 CFR 1910.94 - ventilation

• 29 CFR 1910 Subpart H - hazardous materials

  • 29 CFR 1910.106 - flammable liquids

  • 29 CFR 1910.107 - spray finishing using flammable and combustible materials

  • 29 CFR 1910.120 - hazardous waste operations and emergency response

• 29 CFR 1910 Subpart I - personal protective equipment

  • 29 CFR 1910.132 - general requirements

  • 29 CFR 1910.133 - eye and face protection

  • 29 CFR 1910.134 - respiratory protection

  • 29 CFR 1910.138 - hand protection

• 29 CFR 1910 Subpart Z - toxic and hazardous substances

  • 29 CFR 1910.1000 - air contaminants

  • 29 CFR 1910.1028 - benzene

  • 29 CFR 1910.1200 - hazard communication

Maritime

• 29 CFR 1915 Subpart C - surface preparation and preservation

  • 29 CFR 1915.32 - toxic cleaning solvents

• 29 CFR 1915 Subpart Z - toxic and hazardous substances

  • 29 CFR 1915.1000 - air contaminants

  • 29 CFR 1915.1028 - benzene

  • 29 CFR 1915.1200 - hazard communication

Construction

• 29 CFR 1926 Subpart D

  • 29 CFR 1926.55 - gases, vapors, fumes, dusts and mists

  • 29 CFR 1926.57 - ventilation

  • 29 CFR 1926.59 - hazard communication

    • 29 CFR 1910.1200 - hazard communication

  • 29 CFR 1926.65 - hazardous waste operations and emergency response

• 29 CFR 1926 Subpart E - personal protective and lifesaving equipment

  • 29 CFR 1926.102 - eye and face protection

  • 29 CFR 1926.103 - respiratory protection

    • 29 CFR 1910.134 - respiratory protection

• 29 CFR 1926 Subpart Z

  • 29 CFR 1926.1128 - benzene

The Which OSHA Standards Apply webpage can also help identify other standards that may be applicable to this topic.

Learn More

Where can I learn more?

• Industry Guide 48 - OSHA Construction Standards Requiring Programs, Inspections, Procedures, Records and/or Training highlights standards with special requirements in construction.

• Industry Guide 49 – OSHA General Industry Standards Requiring Programs, Inspections, Procedures, Records and/or Training highlights standards with special requirements in general industry.

• Industry Guide 53 - OSHA Shipyard Employment Standards Requiring Programs, Inspections, Procedures, Records and/or Training highlights standards with special requirements in shipyard employment.

If you would like to receive interpretive guidance on this or any other OSH standard or topic, you can submit your questions using the Ask OSH web form, by e-mail to ask.osh@labor.nc.gov or by calling 919-707-7876.