Reference Source

NFPA 704 fire diamond ratings by chemical

The NFPA 704 'fire diamond' rating for a chemical — the health (blue), flammability (red), instability (yellow) numbers and any special (white) notice — as published on that chemical's own datasheet. Each record is one chemical, with the four quadrants and the datasheet's own wording for what each value means. Answers 'what is the NFPA 704 rating for anhydrous ammonia', 'fire diamond numbers for thionyl chloride', and 'what does a 3 in the blue diamond mean'. NFPA 704 itself is a paywalled standard and the per-chemical ratings are scattered one page at a time across datasheets and SDSs, so no single free table exists — assembly, one source per record.

Records4
Sources4
Verified2026-08-06
Review by2028-08-05
LicenceCAMEO Chemicals is published by NOAA, a US Government agency; its datasheets are US Government works and not copyrightable. The ratings themselves are safety classifications, i.e. facts. The NFPA 704 standard document is not reproduced and must not be — only the per-chemical rating and the datasheet's own short attributed wording.

The data

ChemicalCAS numberHealth (blue)Flammability (red)Instability (yellow)What the rating meansSpecial (white)
AMMONIA, ANHYDROUS7664-41-7310Health | 3 | Can cause serious or permanent injury. | Flammability | 1 | Must be preheated before ignition can occur. | Instability | 0 | Normally stable, even under fire conditions. | Special | | | Note: The Refrigeration System Classification section of the International Mechanical Code requires a value of 3 for the red quadrant (flammability hazard) for indoor ammonia refrigeration equipment.
AMMONIUM NITRATE-PHOSPHATE MIXTURE57608-40-9003Health | 0 | No hazard beyond that of ordinary combustible material. | Flammability | 0 | Will not burn under typical fire conditions. | Instability | 3 | Capable of detonation or explosive decomposition or explosive reaction but requires a strong initiating source or must be heated under confinement before initiation. | Special | OX | Possesses oxidizing properties. | Note: NFPA ratings shown are for ammonium nitrate, CAS number 6484-52-2.OX
CYCLOPROPANE75-19-4140Health | 1 | Can cause significant irritation. | Flammability | 4 | Burns readily. Rapidly or completely vaporizes at atmospheric pressure and normal ambient temperature. | Instability | 0 | Normally stable, even under fire conditions. | Special | | |
THIONYL CHLORIDE7719-09-7402Health | 4 | Can be lethal. | Flammability | 0 | Will not burn under typical fire conditions. | Instability | 2 | Readily undergoes violent chemical changes at elevated temperatures and pressures. | Special | W Reacts violently or explosively with water.W

Where this came from

Every record above links the page it was taken from and quotes the sentence that states it. These are the 4 sources this dataset was assembled from.

Machine-readable

4 records. last verified against source 2026-08-06. due for re-check by 2028-08-05.

Licence. CAMEO Chemicals is published by NOAA, a US Government agency; its datasheets are US Government works and not copyrightable. The ratings themselves are safety classifications, i.e. facts. The NFPA 704 standard document is not reproduced and must not be — only the per-chemical rating and the datasheet's own short attributed wording.