Division 4.3: Substances Which in Contact with Water Emit Flammable or Toxic Gases

This division includes materials are materials that, by contact with water, are liable to become spontaneously flammable or to give off flammable or toxic gas at a rate of 1 L/Kg of the material per hour.

Examples include calcium carbide, lithium metal, and sodium metal.

Image of two jars sitting side by side on a flat surface. A dark glass jar on the left with a white label and small black text. The jar on the right is silver metal with a blue diamond placard. A white flame is at the top of the placard, with the words Dangerous When Wet in the middle, and a white number 4 at the bottom.