zeroresidue.io
US

NFPA 704 Generator

The NFPA 704 standard defines the familiar fire diamond used by emergency responders to size up a material at a glance.

NFPA 704 fire diamond — health 0, flammability 0, instability 0NFPA 704 diamond. Health 0 (blue, left), flammability 0 (red, top), instability 0 (yellow, right). Special hazards (white, bottom): none.000
Ratings (0–4)
Health
0
Flammability
0
Instability
0
Special hazards (white)

Reference / generator only — not a substitute for professional hazard classification; verify against your SDS.

How to read an NFPA 704 diamond

The NFPA 704 “fire diamond” is a square set on its point and split into four quadrants. Three carry a hazard rating from 0 (minimal) to 4 (severe); the fourth flags specific special hazards with a symbol. The colors and positions are fixed, so a compliant placard reproduces them exactly.

  • Left · blue · Health
    How dangerous the material is to a person exposed to it, from minimal (0) to deadly on brief contact (4).
  • Top · red · Flammability
    How easily the material ignites and burns, graded mainly by its flash point, from will-not-burn (0) to ignites at ordinary conditions (4).
  • Right · yellow · Instability
    How readily the material releases energy on its own — through decomposition, polymerization, or reaction with water — from stable (0) to detonates readily (4).
  • Bottom · white · Special hazards
    Reserved for a small set of standard symbols that flag a specific reactive hazard; it carries no 0–4 rating.

Health scale (blue)

0
No health hazard beyond that of an ordinary combustible material; standard firefighting gear is sufficient.
1
Exposure would cause irritation or minor, reversible injury; ordinary protective equipment is adequate.
2
Intense or prolonged exposure could cause temporary incapacitation or lasting injury unless treated promptly; respiratory protection is warranted.
3
Short exposure could cause serious temporary or moderate lasting injury; protective equipment covering all skin is required.
4
Very brief exposure could be fatal or cause major residual injury; entry demands fully encapsulating, specialized protection.

Flammability scale (red)

0
Will not burn under typical fire conditions (for example, it withstands 816 °C (1500 °F) for five minutes without igniting).
1
Must be preheated before it will ignite; flash point at or above 93 °C (200 °F).
2
Ignites after moderate heating or when the surroundings are hotter than normal; flash point between 38 °C and 93 °C.
3
Ignites under nearly all ambient temperatures; flash point below 23 °C with a boiling point at or above 38 °C, or a flash point between 23 °C and 38 °C.
4
Vaporizes rapidly at ordinary temperature and pressure and burns readily; flash point below 23 °C (73 °F) and boiling point below 38 °C (100 °F).

Instability scale (yellow)

0
Normally stable, even when exposed to fire, and does not react with water.
1
Normally stable, but can turn unstable at raised temperature and pressure.
2
Undergoes a violent chemical change at raised temperature and pressure, reacts violently with water, or can form explosive mixtures with water.
3
Can detonate or explosively decompose, but needs a strong initiating source, heating under confinement, or reacts explosively with water.
4
Readily detonates or explosively decomposes at normal temperature and pressure.

Special-hazard symbols (white)

OX
Oxidizer. Supplies oxygen and can start or intensify a fire even without an outside air supply — for example ammonium nitrate or many peroxides.
W̶
Reacts with water. Reacts with water in a hazardous way, so water should not be used to fight the fire — for example sodium metal or calcium carbide. Drawn as a W with a horizontal bar through it.
SA
Simple asphyxiant. A gas that displaces breathable air. Under NFPA 704 this mark is reserved for nitrogen, helium, neon, argon, krypton, and xenon.

Marks such as COR, ACID, ALK, BIO, CYL, or the radioactive trefoil appear on some placards in the field but are not defined by NFPA 704. This generator emits only the three standard symbols above.

Reference only. Not legal or regulatory advice. Verify against the primary source before you act.

How it works

The NFPA 704 standard defines the familiar fire diamond used by emergency responders to size up a material at a glance. Four quadrants — blue for health (left), red for flammability (top), yellow for instability (right), and white for special hazards (bottom) — encode the worst-case hazards of a substance as stored.

Set each 0–4 rating and toggle any standard white-quadrant symbol; the diamond redraws as you go, and you can download the result as an SVG. The three ratings come from your safety data sheet or an authoritative NFPA source — this tool draws the diamond, it does not classify the substance for you.

The colors, 0–4 scale, and the OX / W̶ / SA symbols are the reproducible NFPA 704 notation. Rating descriptions here are written in original prose; consult NFPA 704 for the authoritative definitions.

Related tools

last updated 2026-07-06