NFPA 704 

NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response, or NFPA 704 for short is the fire diamond things. They are typically placed on a door or a container and it gives warnings about what is inside of the container or behind the door. There are three colors and they each have a number 0 through 4 (0 being not present and 4 being extremely).

Red indicates flammability/combustibility (A material with a 4 will likely combust under normal atmospheric temperatures/pressures) (Propane has a flammability rating of 4) .

Blue indicates health hazards (a material with a 4 can cause death or serious harm upon exposure). (Hydrogen cyanide has a health rating of 4).

Yellow indicates reactivity/stability (a material with a 4 can detonate under normal temperatures) (nitroglycerin has a reactivity rating of 4)

The white section doesn't have a number and instead serves as a place for special warnings.
Examples of which include but are not limited to:

OX: indicates the substance is an oxidizer

SA: indicates the substance is a asphyxiant gas

BIO: indicates the substance carries a biological hazard (used for things such as viruses)
RA/RAD: indicates the substance is radioactive
ACID/ALK: indicates the substance is Acid or Alkaline respectively

A: Bro wtf is in this container?
B: Don't open it! the NFPA 704 says it's a health hazard
A: Fuckin nerd

NFPA 704 by Person12350 April 22, 2022

NFPA 704 

NFPA 704 is the official name for Fire Diamonds, which are rhombus-shaped sign that has 4 different colored squares that tell you how dangerous a substance is in four ways: Health (Blue), Reactivity (Yellow), Flammability (Red) and the white square is for Miscellaneous hazards. Each colored square is marked with a number ranging between zero and four. Zero/Empty means that that substance has no danger in that category. 1 = mildly hazardous, 2 = hazardous, 3 = extremely hazardous, and 4 = Lethal.

Hey, did you know that NFPA 704 are also called fire diamonds, saftey squares and figmenty pigmenty crosser tossers?

NFPA 704 by Jqoi Zunderlat March 4, 2021