The highest degree of hazard - severe hazard that a very short exposure could cause serious injury or death.
In the NFPA 704 labeling system, a rating of 4 in any quadrant indicates a high level of hazard. Specifically, it signifies that the material is extremely flammable, poses a significant health risk, or is highly reactive and can explode under certain conditions. This rating alerts responders to the need for extreme caution and specialized handling procedures.
Potential dangers.
Cyclohexane does not have a specific NFPA diamond classification since it is not considered a hazardous material under the NFPA 704 standard.
240
The first guide is from 1960.
0-0-0
The NFPA 704 diamond is a ring of smaller diamonds that are blue, red, yellow and white. A number or symbol in each section indicates the relative danger.
Fire Hazard: 2, Red square Special Information: 4 Health hazard: 1 Reactivity hazard: 3
A "4" in the blue quadrant of NFPA 704 indicates that the substance is known to be highly hazardous to an individual's health. The scale runs from 0 to 4 with 0 being essentially harmless and 4 being extremely harmful or potentially fatal. The number 4 means it is too dangerous to enter the liquid or vapor, as compared with number 3, which means you can work with it if you are fully protected.
The number 4 on the NFPA 704 placard indicates the highest hazard in any of the three categories (health, fire, reactivity).
The NFPA 704 rating for propane is 2 for health (blue), 4 for flammability (red), and 0 for reactivity (yellow). This indicates that propane poses a high flammability risk, being easily ignitable, but it has low toxicity and is stable under typical conditions. The rating system helps emergency responders quickly assess the hazards associated with propane during incidents.
Health (blue) 2 Fire (red) 0 Reactivity (yellow) 0