Toxic

A toxic substance is poisonous and can cause severe harm or death. Exposure must be prevented by following the specified handling instructions and avoiding ingestion, inhalation and skin contact.

Chlorine is a toxic gas, so it must not be smelled deliberately. In a laboratory, it should be handled in a fume cupboard. Dampen a piece of blue litmus paper with a few drops of water: it should be damp, not soaking wet.