Section 4.2.3.3 of NFPA 704 guides how to handle multiple chemicals.
You can combine the worst of each category into a composite, list each individually, or do a hybrid option.
The posts saying there are two chemicals are true but likely incomplete… There are probably several different chemicals and they decided to go with the hybrid method.
My guess is that they combined the worst rating of everything that doesn’t need special handling, and have a stand alone for the chemical that is incompatible with water (or even combined for several chemicals that are incompatible with water).
That makes sense, but it’s still strange because it means in the case of a fire the entire building has to be treated the same anyway because there is something in the building that reacts with water even if its separate.
I guess it is helpful to indicate that there are multiple substances that have different reaction profiles, but it still seems strange to me.
Yeah it’s really there to guide how fucked up it can be and not really be mega prescriptive. It’s not like quantities are on there, either.
Ideally a fire department shows up, sees the signs and then gets in contact with the building owner to start being more specific about what’s ahead of them before they just start dumping a ton of water on the building.
Section 4.2.3.3 of NFPA 704 guides how to handle multiple chemicals.
You can combine the worst of each category into a composite, list each individually, or do a hybrid option.
The posts saying there are two chemicals are true but likely incomplete… There are probably several different chemicals and they decided to go with the hybrid method.
My guess is that they combined the worst rating of everything that doesn’t need special handling, and have a stand alone for the chemical that is incompatible with water (or even combined for several chemicals that are incompatible with water).
That makes sense, but it’s still strange because it means in the case of a fire the entire building has to be treated the same anyway because there is something in the building that reacts with water even if its separate.
I guess it is helpful to indicate that there are multiple substances that have different reaction profiles, but it still seems strange to me.
Yeah it’s really there to guide how fucked up it can be and not really be mega prescriptive. It’s not like quantities are on there, either.
Ideally a fire department shows up, sees the signs and then gets in contact with the building owner to start being more specific about what’s ahead of them before they just start dumping a ton of water on the building.