It means there are two separate chemicals inside of the building. Each chemical would have their individual labels on their containers, but these external signs are for first responders who haven’t entered the building yet.
Let’s say there’s a fire. The red diamond tells them how likely it is that the chemicals are the cause of the fire, and where they should direct their efforts. The blue corner tells them what kind of PPE they need to use if they enter. The yellow tells them what kind of potential explosive risks the chemicals have. And the white one is especially important, because the W means the chemical reacts with water; If there’s a fire at the facility, they can’t simply use fire hoses to fight it.
The reason for listing them separately is because each individual chemical has its own ratings. You can’t simply take the highest of each and combine them into a single sign. For instance, in this case one chemical isn’t flammable but is explosive when heated. The other chemical is flammable but not explosive. So if you see a chemical on fire, you know it’s the second chemical and isn’t explosive. But if you see something that isn’t burning in a room full of fire, you know it’s a potential powder keg waiting to explode.
The reason for listing them separately is because each individual chemical has its own ratings. You can’t simply take the highest of each and combine them into a single sign. For instance, in this case one chemical isn’t flammable but is explosive when heated. The other chemical is flammable but not explosive. So if you see a chemical on fire, you know it’s the second chemical and isn’t explosive. But if you see something that isn’t burning in a room full of fire, you know it’s a potential powder keg waiting to explode.
Okay, so the two signs on the building have a weird combination.
The sign on the left indicates something that isn’t flammable, but reacts with water. The sign on the right indicates something that is flammable, but there’s no risk of reacting to water. If the building caught fire then a first responder on the scene has to read both signs at the same time. They can’t spray the building with water because the non-flammable substance would react with the water.
So why aren’t the signs combined? They have to be treated the same anyway.
But it’s just slapped on the side of the building with no indication of which chemicals the labels are for, I don’t think that’s how it’s supposed to be done. It’d be like mixing two chemicals into a bottle and then putting two labels on it.
I think there should just be one label that combines the warning levels of both i.e. 3-2-2-W
They generally have them on the containment units, and if they’re used elsewhere, on the pipes/machines carrying/using the chemicals.
Now, if they’ve been properly replaced since installation is a completely different question. I’ve seen far too many faded/shredded diamonds on the sides of things.
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 might make 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.
I’m no expert, so I can’t tell for sure, but my guess is that they’re storing two different chemicals. The left one looks like it’s a non-flammable, extremely hazardous material that shouldn’t be exposed to water (maybe an alkali metal, like lithium or sodium). The right one is a hazardous material that is a fire hazard above 93°C (200°F), but otherwise stable (maybe some kind of diesel?)
So… If I had to take a wild guess, diesel and lithium batteries?
Reading this made me wonder how metallic lithium is stored and, guess what, it’s stored in oil. So, which label do you use for a container holding lithium and oil? I’m guessing you need two, one for the lithium and one for the oil. And here we are.
No, I don’t think this building is filled with lithium and covered in oil, but I suspect there is more than one container containing metallic lithium covered in oil.
As others have said, these are NFPA signs.
What I want to know is why there are two different ones. What the hell does that mean?
It means there are two separate chemicals inside of the building. Each chemical would have their individual labels on their containers, but these external signs are for first responders who haven’t entered the building yet.
Let’s say there’s a fire. The red diamond tells them how likely it is that the chemicals are the cause of the fire, and where they should direct their efforts. The blue corner tells them what kind of PPE they need to use if they enter. The yellow tells them what kind of potential explosive risks the chemicals have. And the white one is especially important, because the W means the chemical reacts with water; If there’s a fire at the facility, they can’t simply use fire hoses to fight it.
The reason for listing them separately is because each individual chemical has its own ratings. You can’t simply take the highest of each and combine them into a single sign. For instance, in this case one chemical isn’t flammable but is explosive when heated. The other chemical is flammable but not explosive. So if you see a chemical on fire, you know it’s the second chemical and isn’t explosive. But if you see something that isn’t burning in a room full of fire, you know it’s a potential powder keg waiting to explode.
Okay, so the two signs on the building have a weird combination.
The sign on the left indicates something that isn’t flammable, but reacts with water. The sign on the right indicates something that is flammable, but there’s no risk of reacting to water. If the building caught fire then a first responder on the scene has to read both signs at the same time. They can’t spray the building with water because the non-flammable substance would react with the water.
So why aren’t the signs combined? They have to be treated the same anyway.
Two different chemicals to be aware of
But it’s just slapped on the side of the building with no indication of which chemicals the labels are for, I don’t think that’s how it’s supposed to be done. It’d be like mixing two chemicals into a bottle and then putting two labels on it.
I think there should just be one label that combines the warning levels of both i.e. 3-2-2-W
Why are you assuming the chemicals are mixed together inside the building? Two separate chemicals, two distinct risks.
But the building, as a whole, pesents the combined risk of both chemicals.
First responders need to know that there are two chemicals inside so that they don’t stop taking precautions when they encounter the first one.
They’re required to be individually labeled/categorized. And supposed to be on 2 exterior walls, and any doors, and on the containers themselves
I’m sure they’ll be labelled inside too.
Sure, but I don’t think the building should have two labels. I think it should have one label that reflects a warning for everything in the building.
Imagine you have a crate with two different chemicals. The chemicals are in different bottles so they aren’t mixed, and each bottle has its own label.
Should the crate have two unidentified labels like this, or one? There’s no indication what those labels refer to on the building.
if the chemicals are extremely different in hazard it could be useful to know that it’s not a mixture, like a superacid and a strong base.
i would hope that there would be labels inside the building that would indicate which is which, but who fucking knows with the us lol
They generally have them on the containment units, and if they’re used elsewhere, on the pipes/machines carrying/using the chemicals.
Now, if they’ve been properly replaced since installation is a completely different question. I’ve seen far too many faded/shredded diamonds on the sides of things.
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 might make 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.
I’m no expert, so I can’t tell for sure, but my guess is that they’re storing two different chemicals. The left one looks like it’s a non-flammable, extremely hazardous material that shouldn’t be exposed to water (maybe an alkali metal, like lithium or sodium). The right one is a hazardous material that is a fire hazard above 93°C (200°F), but otherwise stable (maybe some kind of diesel?)
So… If I had to take a wild guess, diesel and lithium batteries?
Reading this made me wonder how metallic lithium is stored and, guess what, it’s stored in oil. So, which label do you use for a container holding lithium and oil? I’m guessing you need two, one for the lithium and one for the oil. And here we are.
No, I don’t think this building is filled with lithium and covered in oil, but I suspect there is more than one container containing metallic lithium covered in oil.