This sign warns about storing Class 5 Oxidising Agents/Substances in places like buildings, vehicles, or containers. Class 5, Division 5.1, Oxidising Agents/Substances are substances that, in certain conditions, can make other materials or substances burn more easily.

The sign has a flame over a circle symbol with "OXIDISING AGENT" written below, followed by large, bold numbers "5.1". It's yellow with black wording and symbols.