Any ideas what these signs on this building mean?
Any ideas what these signs on this building mean?
Aside of these signs and the address numbers, the building is completely unmarked.
52 comments
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Those diamonds indicate what chemical hazards are inside the building, for fire and rescue operations.
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Thank you!
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So in that building there's a nonflammable reactant that's super dangerous to life and reacts with water, and a flammable chemical that is quite toxic.
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What's interesting is they could have made one compound NFPA diamond that encompasses the worst ratings of everything in the building instead of two individual diamonds. The primary intent of these on buildings is to inform first responders of what they might be rushing into.
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One diamond might give conflicting or incorrect info if there's several things that would react to logically correct answers when firefighting. Last thing you need is to start a reaction when everything is already on fire because while it lists one reactant, it supercedes another reactant that would have been displayed on a secondary diamond.
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Those are hazardous chemical markers. You commonly see them on tanker trucks as well.
The numbers range from 0 to 4, with higher numbers indicating more risk. The red top corner is flammability. The right yellow corner is instability; How likely it is to react with other things around it. The left blue corner is risk to health; Even if a chemical isn’t unstable or flammable, it can still be hazardous. The bottom white is for special markings. In this case, one of those chemicals is marked with a W, meaning it reacts to water.
So if there’s a fire at the warehouse, this tells the responding crew “hey just so you know, there’s some nasty shit in here. One presents a severe health hazard, becomes potentially explosive when heated, and reacts with water… But at least it isn’t flammable. The other is flammable and can present a moderate health risk. Because of the one on the left, it would be a bad idea to use water to fight this fire.”
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100% correct answer.
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They’re NFPA 704 signs.
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Thank you!
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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?
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Two different chemicals to be aware of
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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
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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).
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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.
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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?
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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.
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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.
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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.
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Here's my favourite warning, can you guess what it is?
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Chlorine trifluoride! Nasty, NASTY shit. Guess which industry I worked in as safety!
Edit: I remembered this quote about ClF3 from John D. Clark's book "Ignition!" and wanted to share. For the non-scientists, hypergolic means it'll ignite on contact with another substance without an outside energy source, like a spark.
It is, of course, extremely toxic, but that’s the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively. It can be kept in some of the ordinary structural metals-steel, copper, aluminium, etc.-because of the formation of a thin film of insoluble metal fluoride which protects the bulk of the metal, just as the invisible coat of oxide on aluminium keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.
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https://www.science.org/content/blog-post/things-i-won-t-work-dioxygen-difluoride
Probably related to this, very fun column to read.
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404 not found
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Holy shit fours on blue AND yellow, AND it's an oxidizer? My guess is some kind of halogenation agent, likely fluorine based. The lack of flammability with those stats makes me think it's an inorganic compound, probably some wretched fluorine abomination.
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If I'm to understand mic_check_one_two@lemmy.dbzer0.com correctly, it's something that's:
Extremely hazardous,
non flamable, Extremely unstable, Reactive to waterAnd if ox means oxidising, reacts to exposure to oxigen.
I thought Lithium, but that catches fire and this is non-flammable.
I haven't a clue what this could be, but now I'm curious.
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Similar to the markings used on trucks hauling hazardous materials. Might be for the fire dept if the place goes up in flames.
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Likely it's a water treatment plant, probably a dosing plant for drinking water. Signs indicate which kind of chemical hazards are present, stored in relatively large and concentrated quantities.
No other signage because it's critical infrastructure, and if you need to know, you know.
Dosing buildings like this are common downstream from dams and reservoirs. Where I live, they are also mostly unmarked and heavily fenced off. Same as electrical substations, phone exchanges and other infra.
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