A biological hazard, or biohazard, is a living organism or a substance produced by one that can cause illness or injury. Examples include bacteria, viruses, fungi and mold, parasites, blood and body fluids, and toxins from plants, animals and insects.
Biological hazards are present in healthcare and laboratories, but also in agriculture, waste management, wastewater treatment, construction, landscaping, food processing and any job that involves contact with people, animals or contaminated materials.
Common Examples of Biological Hazards
- Bloodborne pathogens: hepatitis B, hepatitis C and HIV in blood and certain body fluids
- Airborne infections: tuberculosis, influenza and other respiratory diseases
- Mold and fungi: mold in water-damaged buildings, and histoplasmosis from bird or bat droppings
- Vector-borne diseases: Lyme disease from ticks and West Nile virus from mosquitoes for outdoor workers
- Animal-related hazards: zoonotic diseases from livestock, wildlife or laboratory animals
- Sewage and waste: bacteria and viruses in wastewater, garbage and medical waste
Which OSHA Rules Apply?
OSHA does not have a single standard covering all biological hazards. Instead, several requirements may apply:
- Bloodborne Pathogens (29 CFR 1910.1030): covers occupational exposure to blood and other potentially infectious materials, and requires the fluorescent orange or orange-red biohazard symbol on regulated waste and contaminated items.
- Respiratory Protection (29 CFR 1910.134): applies when respirators are used to protect against airborne biological agents.
- Personal Protective Equipment (29 CFR 1910.132): requires hazard assessment and appropriate PPE.
- Sanitation (29 CFR 1910.141): covers washing facilities, toilets and waste disposal.
- General Duty Clause: requires employers to protect workers from recognized serious hazards, including biological ones not covered by a specific standard.
Laboratories often follow the CDC and NIH publication Biosafety in Microbiological and Biomedical Laboratories, which defines Biosafety Levels 1 through 4 based on the risk of the agents handled.
How to Control Biological Hazards Step by Step
- Identify the hazards. Use a risk assessment to find tasks involving people, animals, waste, water damage or outdoor exposure.
- Eliminate or reduce sources. Fix leaks that cause mold, control pests and use safer sharps or closed systems.
- Use engineering controls. Ventilation, biosafety cabinets, isolation rooms and barriers reduce exposure.
- Set work practices. Require hand hygiene, safe handling and disposal, and cleaning and disinfection procedures.
- Provide PPE. Gloves, eye and face protection, gowns and respirators as the hazard requires.
- Offer vaccination and medical follow-up. Make vaccines available where appropriate, such as hepatitis B for exposed workers.
- Train employees. Explain the hazards, controls, symptoms and how to report exposures.
Common Mistakes to Avoid
- Assuming biological hazards only matter in healthcare.
- Dry sweeping bird droppings or moldy materials, which spreads spores.
- Ignoring tick and mosquito protection for outdoor crews.
- Not having a clear procedure for reporting and following up on exposures.
How SMS360 Helps
SMS360's Risk Assessment module helps teams identify biological hazards by task or location, rate the risk, and document the controls in place. Required improvements can be assigned as actions with owners and due dates, so hazards are tracked through to resolution.
Frequently Asked Questions
What are the four levels of biohazard?
Laboratories use Biosafety Levels 1 through 4, defined by the CDC and NIH. BSL-1 covers agents not known to consistently cause disease in healthy adults, while BSL-4 covers dangerous agents that pose a high risk of life-threatening disease and have no available vaccine or treatment. Each level adds stricter containment and practices.
Is mold a biological hazard?
Yes. Mold is a biological hazard that can cause allergic reactions, asthma symptoms and other respiratory effects, especially for sensitive individuals. It commonly grows in water-damaged buildings, and remediation work should use controls that prevent spreading spores.
Does OSHA have a biological hazards standard?
Not a single comprehensive one. The Bloodborne Pathogens standard covers blood and certain body fluids, and other standards such as respiratory protection, PPE and sanitation apply. For other biological hazards, the General Duty Clause requires employers to protect workers from recognized serious hazards.
