Hydrogen (H2)

Hydrogen is a colourless, odourless, highly combustible gas, which forms an explosive mixture with air. Hydrogen is the lightest of the gases and it reacts violently with halogens and most halogen compounds.

Effect on the skin

Hydrogen flames are diffi cult to detect and will cause severe burns upon contact.

Inhalation

Pure hydrogen gas is not poisonous. Inhalation of hydrogen gas will make a person’s voice become high-pitched. In high concentrations it can displace oxygen and cause asphyxiation in confi ned spaces. Symptoms of oxygen defi ciency begin to appear when the oxygen concentration falls below 18%.

First aid

Move the exposed person immediately to give them fresh air, but do not enter any space with insuffi cient oxygen without a compressed air respirator. Provide oxygen or give mouth-tomouth resuscitation if necessary.