Blue. Yellow is reactivity, red is fire.
red= fire harzard blue= health hazard yellow= reactivity hazard white= special hazard
Fire Hazard: 2, Red square Special Information: 4 Health hazard: 1 Reactivity hazard: 3
3
The number 4 on the NFPA 704 placard indicates the highest hazard in any of the three categories (health, fire, reactivity).
The biological hazard marking is a circle overlaid by 3 linked broken circles. While it identifies something that is alive and dangerous to people, the symbol itself has no meaning.
NFPA 704 Hazmat color codes:blue -- health hazard (4 being deadly)red -- fire hazard (4 being flash point below 73 F)yellow -- reactivity (4 may detonate) andwhite -- specific hazard (no water, radioactive, acid, alkali, corrosive, oxidizer)Read more: What_does_the_National_Fire_Protection_Association_704_blue_color_code_stand_for
Right isosceles triangle with a blue background and red lettering
Fragmentation hazard
hazard substance
Right isosceles triangle with blue background and red lettering
Yellow 3