Danger Diamond

The danger diamond is a symbol that came to Europe from the United States. It was defined by the National Fire Protection Association (NFPA) (National Fire Protection Association) and is described in the NFPA 407 standard. This sign is mainly used by emergency services to quickly identify a hazardous substance. The specific properties of this substance, the health hazard and the method of extinguishing a fire of this substance. It consists of four colored fields with numbers from 0 to 4. The colors and numbers mean:

Blue field – health hazard

0. No health hazard in case of normal contact.
1. May cause temporary health damage.
2. Contact may cause temporary health damage with risk of complications.
3. Short contact may cause serious poisoning
4. Very short contact may cause death or serious poisoning

Red field – fire hazard/flammability

0. Non-flammable substance.
1. The material must be heated strongly to ignite. Flash point above 93ºC.
2. The substance must be heated to ignite. Flash point 38 ÷ 93ºC
3. Liquids and solids that ignite at room temperature. Flash point 27 ÷ 38ºC
4. The substance immediately disperses in air, creating an explosive mixture.

Yellow field – instability/reactivity

0. Stable under normal conditions, does not react with water, does not react with open flames.
1. Stable under normal conditions, but may become unstable under increased pressure or at higher temperatures.
2. Undergoes dangerous chemical changes at elevated temperatures and pressures, reacts with water, or as a result of reaction with it produces explosive products.
3. Capable of detonation, or explosive decomposition under the influence of a strong stimulus, must be heated to  initiate the reaction, reacts explosively with water, or explodes from shock.
4. A substance capable of detonation or vigorous decomposition under normal conditions of temperature and                                                           pressure.

White field – additional information

OXY or OX – Oxidant.
W – Reacts vigorously to contact with water. Often in an unpredictable manner. In case of fire, do not extinguish with water.
SA – Asphyxiating gas.
COR – Corrosive/corrosive substance (acid or base).
CRIO or CRY – Cryogenic substance generating low temperatures (e.g. dry ice).
BIO – Biological hazard.
POI – Poison.

💡 Application in the Netherlands

The danger diamond can be used to supplement GHS markings, especially in large industrial plants, but cannot replace mandatory GHS markings.