variola virus, refer to biological substances that pose a threat to the health of living organisms, viruses

alert anthrax area attention bacteria bio biohazard biohazards biologic biological biology black caution chemical contaminated danger dangerous ebola epidemic fever forbidden hazard hazardous hazards health hemorrhagic hot icon indicating lab laboratory living marburg medical organisms poison pose presence protect protection refer render research restricted risk sars science scientific scientist security sign substance substances symbol that threat toxic triangle variola virus viruses yellow zone