The first guide is from 1960.
Cyclohexane does not have a specific NFPA diamond classification since it is not considered a hazardous material under the NFPA 704 standard.
240
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.
Potential dangers.
The number 4 on the NFPA 704 placard indicates the highest hazard in any of the three categories (health, fire, reactivity).
Health (blue) 2 Fire (red) 0 Reactivity (yellow) 0
Fire Hazard: 2, Red square Special Information: 4 Health hazard: 1 Reactivity hazard: 3
There are reports that tert-Butyl hydroperoxide has an NFPA 704 rating of 4-4-4, but it is not available in anything over 90 percent concentration, having 2-2-3. If you are ever in a place that needs such stuff, you are strongly urged to find a different job.
It is the yellow section.
The NFPA 704 symbol for acetylene is a blue diamond with a white flame symbol on top, a red health hazard rating of 4 (extreme), a blue flammability rating of 4 (extreme), and a yellow reactivity rating of 0 (stable).
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