Hydrogen sulphide gas is heavier than air and it may accumulate in low lying areas and sumps etc. Entry into such areas must only be performed using full respiratory protection. Hydrogen sulphide is not usually segregated for storage. Heat or ignition sources may ignite product. Sulphur dioxide is one of the products of combustion of hydrogen sulphide.
Sulphur dioxide is a severe respiratory irritant.
Commence CPR if breathing has stopped. Keep at rest. Call for medical attention. Summon medical aid immediately. It is not normally segregated or stored but is normally piped directly to a nearby sulphur plant where it is oxidized to elemental sulphur.