 thumb|200px|right|the international symbol for biological hazard. biological hazards, also known as biohazards, refer to biological substances that pose a threat to the health of living organisms, primarily that of humans. this can include medical waste or samples of a microorganism, virus or toxin (from a biological source) that can affect human health. it can also include substances harmful to other animals. the term and its associated symbol are generally used as a warning, so that those potentially exposed to the substances will know to take precautions. the biohazard symbol was developed in 1966 by charles baldwin, an environmental-health engineer working for the dow chemical company on the containment products. it is used in the labeling of biological materials that carry a significant health risk, including viral samples and used hypodermic needles. in unicode, the biohazard symbol is u+2623 (â£).u+2623 ==classification== bio hazardous agents are classified for transportation by un number:usda policies and procedures on biohazardous waste decontamination, management, and quality controls at laboratories and technical facilities * category a, un 2814- infectious substances affecting humans and animals: an infectious substance in a form capable of causing permanent disability or life-threatening or fatal disease in otherwise healthy humans or animals when exposure to it occurs. * category b, un 2900- infectious substances affecting animals only: an infectious substance that is not in a form generally capable of causing permanent disability of life-threatening or fatal disease in otherwise healthy humans and animals when exposure to themselves occurs. * category c, un 3373- biological substance transported for diagnostic or investigative purposes. * regulated medical waste, un 3291- waste or reusable material derived from medical treatment of an animal or human, or from biomedical research, which includes the production and testing of biological products. == levels of biohazard ==   the united states centers for disease control and prevention (cdc) categorizes various diseases in levels of biohazard, level 1 being minimum risk and level 4 being extreme risk. laboratories an
Biological_hazards Safety Security