Blood-borne viruses (BBVs)

Blood-borne viruses are viruses that some people carry in their blood. They may cause severe disease in some people and few or no symptoms in others. Some of the main BBVs are:

• hepatitis B, C and D viruses, which cause the liver disease hepatitis
• human immunodeficiency virus (HIV), which causes AIDS (acquired immune deficiency syndrome) and affects the body's immune system

Occupations that may be at risk include work in the refuse and recycling industry, laundry work, laboratory work, vehicle recovery and repair, correctional work, emergency response, mortuary work, hairdressing, beauty therapy, dentistry, needle exchange services, plumbing, local authority work, tattooing and health care. These precautions can reduce the risk of infection:

• put in place an infection control policy that sets clear guidelines for everyone
• avoid contact with blood or body fluids where possible, and cover breaks in exposed skin with waterproof dressings or gloves
• treat all blood and blood products as if they were infectious
• use engineering controls, for example needle-safe systems
• use safe work practices, with documented procedures for handling and disposing of contaminated sharps, handling specimens, and handling contaminated laundry, items and surfaces
• wear suitable PPE to avoid contamination, for example gloves, goggles or a visor, and disposable protective clothing such as aprons
• offer appropriate vaccination where available, particularly hepatitis B for relevant exposure; there is no vaccine for HIV or hepatitis C, so vaccination does not replace exposure prevention
• have emergency procedures and post-exposure plans for anyone who has an exposure incident, such as a needle-stick injury
• follow good basic hygiene, including washing hands before and after wearing gloves and avoiding hand-to-mouth or hand-to-eye contact

Carbon monoxide

Carbon monoxide (CO) is a colourless, tasteless poisonous gas that can build up to dangerous levels when petrol-powered equipment and gas appliances are used. It can kill.

The most common symptoms of CO poisoning are headache, dizziness, weakness, nausea, vomiting, chest pain and confusion. People who are asleep, or who have been drinking alcohol, can die from CO poisoning before ever having symptoms.

Workers may be exposed to harmful CO levels in boiler rooms, warehouses, petroleum refineries, pulp and paper production and steel production, and around docks, blast furnaces and coke ovens.

To reduce the chance of CO poisoning at work, employers should:

• install an effective ventilation system that removes CO from work areas
• keep equipment and appliances that can produce CO, such as water heaters, space heaters and cooking ranges, in good working order, to promote safe operation and reduce CO formation
• consider switching from petrol-powered equipment to equipment powered by electricity, batteries or compressed air, if it can be used safely
• prohibit petrol-powered engines or tools in poorly ventilated areas
• provide personal CO monitors with audible alarms where exposure is possible
• test the air regularly in areas where CO may be present, including confined spaces
• use a full-facepiece pressure-demand self-contained breathing apparatus (SCBA), or a combination full-facepiece pressure-demand supplied-air respirator with an auxiliary self-contained air supply, in areas with high CO concentrations, meaning atmospheres that are immediately dangerous to life and health
• do not assume a dust mask or ordinary gas filter protects against CO, or that any filtering respirator supplies oxygen. RPE selection for known CO conditions needs specialist assessment; unknown, oxygen-deficient or immediately dangerous atmospheres require a fully planned specialist response, not improvised entry
• educate workers about the sources and conditions that can lead to CO poisoning, its symptoms, and how to control exposure. For necessary confined-space entry, testing must address oxygen, CO and other assessed toxic or flammable hazards; a normal oxygen reading does not show that CO is absent
• report to the employer any situation that might cause CO to accumulate
• be alert to ventilation problems, especially in enclosed areas where the gases of burning fuels may be released
• report complaints of dizziness, drowsiness or nausea promptly
• avoid gas-powered engines, such as those in pressure washers, heaters and forklifts, in enclosed spaces

Summary notes for Element 7 · Cheat sheet · Glossary. A study aid, not published or endorsed by NEBOSH.