Discomfort arising from Inhalation of Gases

Nature/Causes:

Discomfort after inhaling a small amount of gas/vapour (e.g. sulphur dioxide, bromine or ammonia) from reaction mixtures or town gas from leaking gas taps.

Safety Precautions:

• Experiments involing harmful gases/vapour should be done on a small scale and inside a fume cupboard.
• Microscale chemistry apparatus can also be used to reduce the generation of harmful gases/vapour.
• Good ventilation of the laboratory should always be maintained by opening the windows, switching on the ceiling fans and exhaust fans as appropriate. It is helpful to leave the fan of the fume cupboard operating during the whole practical lesson when these experiments are being done.
• When testing for the odour of a gas, students should be trained to fan the gas gently to the nose but not smell it directly over the container.
• Do not allow asthmatics to smell harmful or irritating gases/vapour.