biohazard sign of biological threat alert black yellow triangle signage text , large detailed sticker closeup

abstract acid agent alert bacteria bacterial beware bio biohazard biologic biological biology black caution chemical chemistry closeup contagious contaminated contamination danger dangerous disaster disease diseases emergency environment epidemic experiment forbidden hazard hazardous hazmat health icon ill illness infected infectious isolated lab label laboratory leak macro medical medicine notice organic poison protect protection quarantine reactor research restricted risk safety science scientific security sign signage signal substance symbol text threat toxic triangle virus viruses warfare warn warning waste weapon yellow