fatal hydrogen sulphide h2s poisoning in confined spaces this paper deals with the problem of fatal accidents that occur repeatedly in confined spaces with particular attention to exposure to hydrogen sulfide h2s this at high concentrations appears to be the most compatible with the dynamics of many recent incidents with sudden death h2s offers little chance to escape at high concentrations because of the smell that causes paralysis of olfactory nerves and sudden loss of consciousness besides the problem of acute exposure to high concentrations health effects may also be caused by prolonged and repeated exposures to lower doses at low concentrations can occur eyes irritation with keratoconjunctivitis and at higher concentrations the risk of pulmonary oedema or chronic central nervous system sequelae in this paper several aspects are detailed including an interpretative analysis of the content of articles 66 and 121 of legislative decree 812008 and subsequent amendments the work contexts where h2s is present as a raw material or product of the process and the effects on human health moreover due to few epidemiological initiatives at national level some aspects related to the accident dynamics are taken into account through the reconstruction of cases of fatal accidents occurred in italy in recent years and comparing it with that reported in the literature of other countries