Hazard symbol

Malay: Simbol bahaya · Chinese: 危险符号

A hazard symbol is a standard, internationally recognised sign printed on a chemical container to warn of a specific danger. Each symbol stands for one kind of hazard, for example a flame for flammable substances, a corrosion picture for corrosive substances, and a skull-and-crossbones for toxic substances. Because the symbol is understood without words, it tells anyone in the laboratory how the chemical must be handled before they even read the name. Recognising these symbols and stating the correct safety precaution is a standard question in the SPM Chemistry papers (4541).

For example, if a bottle shows the corrosive symbol, you know to wear safety goggles and gloves and to avoid skin contact; if it shows the flammable symbol, you keep it away from a naked flame or a hot Bunsen burner. The point of the symbol is to prompt the right precaution before the chemical is used, not after an accident. In an exam answer you should name both the hazard the symbol shows and the precaution it calls for, because a precaution without the reason, or a hazard without the action, usually earns only part of the mark.

The confusion to avoid is mixing up the hazard symbol with the chemical label. The symbol is the picture warning of the danger, while the label is the fuller written information, the substance’s name, its concentration and its hazards in words. A second slip is treating the symbol as decoration; it is a specific instruction to take a specific precaution.

Within this chapter, hazard symbols open the safety section and lead directly into the paired terms corrosive and toxic, and into wearing goggles and using a fume cupboard. Our teachers help you match each symbol to its precaution so the safety marks are secure.