Occupational Hazards of Benzene

Welcome to this Chemscape presentation on benzene. In this video, we will review the hazards of benzene and how to work safely with the product.

What is Benzene?

Benzene is a common chemical. It is a clear, colorless, and extremely flammable liquid with a sweet odor.

Major Sources of Benzene Exposure

Benzene is a frequently used and produced chemical in manufacturing as well as the oil and gas industry. It is a natural part of crude oil and gasoline. Benzene is a raw material used to make other chemicals, including plastics, lubricants, rubbers, dyes, detergents, drugs, and pesticides. 

Major Sources of Benzene Exposure

Benzene can be found in crude oil and natural gas condensate, drilling fluids, emissions from stacks, flares, hydrocarbon storage facilities, and glycol dehydrators, gasoline, vehicle exhaust, solvents and reagents in laboratories, cigarette smoke.  

Side Effects of Benzene Exposure

Benzene has both physical and health hazards. It is a highly flammable liquid and vapor. It is an irritant to the skin and eyes. Prolonged exposure may cause genetic defects, cancer, and damage to the blood system. Inhalation is the most common route of entry for benzene, followed by skin absorption. Breathing in high doses of benzene can affect the nervous system, which can lead to drowsiness, dizziness, headaches, tremors, confusion, and/or unconsciousness. 

Long-Term Effects of Benzene Contamination

Consuming foods or fluids contaminated with high levels of benzene can cause vomiting, stomach irritation, dizziness, sleepiness, convulsions, and a rapid heart rate. In extreme cases, inhaling or swallowing very high levels of benzene can be deadly. Exposure to benzene liquid or vapor can irritate the skin, eyes, and throat. Benzene left on skin can result in redness and blisters. Long-term exposure to benzene mainly harms the bone marrow, the soft inner parts of bones where new blood cells are made. This can result in anemia, a low red blood cell count, which can cause a person to feel weak and tired, a low white blood cell count, which can lower the body's ability to fight infections and might even be life-threatening, a low blood platelet count, which can lead to excess bruising and bleeding. 

There is evidence that long-term exposure to benzene might harm reproductive organs. Some women who have breathed in high levels of benzene for many months have had irregular menstrual periods and ovary shrinkage. It is not known if benzene exposure affects the fetus in pregnant women or fertility in men. Benzene is a confirmed human carcinogen. Long-term exposure to benzene may increase the incidence of leukemia and lymphomas. Your health and safety legislation will have general and specific requirements related to benzene. An occupational exposure limit, OEL, for benzene will be provided. This limit applies to workers directly involved with tasks using benzene or products containing benzene and to other workers in the workplace who may be exposed to benzene indirectly from these operations. It is important to note that OELs represent standards for the protection of the healthiest workers. Steps must be taken to keep benzene levels as low as reasonably achievable. 

Minimizing Benzene Exposure with the Hierarchy of Controls

Now, let's review safe work practices using the hierarchy of controls to limit your exposure to benzene. Preventing exposure to benzene is the best way to protect health. While it is difficult to eliminate the presence of benzene in many petroleum industries, it's still important to eliminate benzene where you can in jobs like cleaning, furnishing, or painting.  

Substitution

One option to control exposure to benzene is to use other solvents when practicable. For example, some alcohols and cyclohexane can be substituted for benzene as a solvent in laboratory procedures. For example, heptane, which has a similar chemical formula to benzene, is also often used as a substitute. However, substitution may not always be possible when benzene is the raw material for the manufacture of another product. In addition, the substitutes may have their own health hazards. 

Engineering Controls

Engineering controls are processes used to reduce exposure to a substance. You should understand and be trained on the proper operation and maintenance of these systems. Local exhaust ventilation hoods, fume hoods, glove boxes, and automatic pumps are common examples of engineering controls. Work practices that can be used in the workplace to reduce exposure to benzene include training programs for chemical handling and emergency situations, restricting access to areas where products containing benzene are used, risk assessments, work permits, and safe operating procedures, eating, drinking, and smoking in areas separate from the workplace where products containing benzene are used or stored, washing hands and face before eating, drinking, or smoking, practice basic hygiene practices such as decontamination at the end of the work shift, including changing out of work clothes, washing hands, and showering if possible. 

Administrative Controls

Air monitoring is often needed to ensure that the occupational exposure limit is not exceeded. Occupational health professionals are needed to take valid measurements. Protection from benzene exposure may require you to wear protective clothing, like coveralls. If you work in the petroleum industry, it should be flame-resistant. If benzene fluids contact your skin, you should wash it off without delay. A respirator protects you from inhaling airborne vapors. Use the respirator and cartridge recommended. It has been chosen based on airborne concentrations of benzene at the worksite. Organic vapor cartridges should be used to filter benzene. Since benzene and benzene vapors can be absorbed through the skin, chemical-resistant gloves and other protective clothing are needed for workers who handle the chemical or may be exposed to airborne vapors. 

Personal Protective Equipment (PPE)

Safety glasses can be a site minimum for PPE, but workers who are at risk of contact with fumes or liquid need to wear close-fitting goggles or full-face respirator masks to protect the eyes from irritation or splashes, cleaning up spills quickly and properly using appropriate PPE and clothing, eliminate heat and ignition sources. For major spills, put on an escape-type respirator and immediately exit the area. 

Storage guidelines. Benzene is extremely flammable, so controlling the sources of ignition and heat are important. Containers need to be tightly closed when not in use or empty to control vapors. Store product in cool, well-ventilated areas out of direct sunlight and away from heat and ignition sources. Products with benzene need to be kept separate from incompatible materials like oxidizers and corrosives. Store in an approved fire-resistant area, clear of combustible and flammable materials. 

Limit Benzene Exposure

Electrically bond and ground containers. Vehicles need to be grounded during transfer of products with benzene. Benzene exposure is cumulative, so it is important to reduce benzene exposure in all areas of life. Cigarette smoke is a major source of benzene exposure. Limit exposure to gasoline fumes. Avoid skin contact with gasoline. Limit the time you spend near idling car engines, as exhaust fumes contain benzene. Limit or avoid exposure to fumes from solvents, paints, and art supplies, especially in unventilated spaces. An administrator can run a report in the SDS binder system to identify benzene. The resulting list of products will contain benzene in the ingredients. Stay safe at work so you can stay healthy in your personal life. If you have further questions regarding this topic, please contact your health and safety representative.