The presence of hydrogen sulfide, (H2S) in corrosive oil and gas production poses its own specific threat to the integrity of the production system. Many materials suffer from cracking of various forms when exposed to H2S which may result in the catastrophic failure of equipment with the attendant risk of releasing the contents into the environment. Beside the general risks associated with release of hydrocarbons in terms of pollution and fire, the release of H2S exposes persons in the vicinity to the risks of poisoning and death. For these reasons the materials’ engineer is mindfid of the need to select materials of proven resistance to cracking in H2S-containing environments. There is a clear driving force for appropriate materials’ requirements when exposed to H2S. There cannot be any excuse for ignorance of the risks involved.