A biological hazard is any biological substance, organism, or material that poses a risk to human health.
A biological hazard, or biohazard, refers to any biological agent or material — including bacteria, viruses, fungi, and certain biological toxins — capable of causing illness or infection in humans. Occupational exposure to biohazards can occur through direct contact, inhalation, ingestion, or injury from contaminated sharps, and is a particular concern in healthcare, laboratory, waste management, and agricultural settings. Biohazard controls typically include engineering measures such as biosafety cabinets, administrative practices like proper waste segregation and labeling, and PPE such as gloves, gowns, and respiratory protection, selected based on the specific biological agent and route of potential exposure.
A clinical laboratory technician handling patient blood samples wears gloves and a lab coat, disposes of used sharps in a puncture-resistant biohazard container, and works within a certified biosafety cabinet when processing samples that may contain infectious pathogens.
Healthcare, laboratory research, waste management, agriculture, and veterinary services are among the industries with the highest occupational biohazard exposure risk, given the frequent handling of bodily fluids, pathogens, animal waste, or biological samples inherent to that work.
Biohazards are commonly identified using the standardized biohazard symbol, along with color-coded containers (often red or orange) for biohazardous waste, and specific labeling requirements outlined in an organization's exposure control plan or hazard communication program.
The biosafety level (BSL) system, ranging from BSL-1 to BSL-4, classifies biological agents and the corresponding containment practices required based on the severity of risk they pose, from low-risk organisms unlikely to cause disease in healthy adults (BSL-1) to extremely dangerous pathogens requiring maximum containment (BSL-4). Understanding the appropriate biosafety level for a given agent helps determine the facility design, PPE, and procedural controls required for safe handling.
Part of SafetyIQ's EHS glossary: plain-English definitions of workplace health and safety terms.
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