This sign indicates that the substance in question is a serious risk to health and can cause death.
Explosive Substances
This sign indicates that the substance in question may explode if ignited in air or exposed to heat. Explosions may also occur as a result of a sudden shock or friction.
Harmful Substances
A variant of the sign to the left, displayed with an "h". The sign indicates that the substance is harmful and is a clear health risk, but it is not as harmful as toxic substances.
Oxidizing Substances
This sign indicates that the substance in question may produce lots of heat as they react with other materials, creating a fire risk.
Corrosive Substances
This sign indicates that the substance in question may destroy living tissue, including the eyes and skin.
Highly Flammable Substances
This sign indicates that the substance in question, which could be a solid, liquid or gas, may easily catch fire in a laboratory under normal conditions.
Irritant Substances
A variant of the sign to the left, displayed with an "i". The sign indicates that the substance is not corrosive, but may cause blistering or reddening of the skin. The effect can be immediate or appear after long or repeated contact with the substance.