b'Products and FacilitiesSour Crude Oil(DOT ERG 131),Sour Gas(DOT ERG 117)Products containing little or no sulfur are often referred to as sweet, where- as,productscontaininghighconcentrationsofsulfurandhydrogensulfide (H 2 S)arecommonlyreferredtoassour.Hydrogensulfideisacolorless,https://vimeo.com/436591302flammable,corrosiveandextremelytoxicgaswithanoffensiverottenegg odor.It is created naturally by the bacterial breakdown of sulfur-containing organicmaterials.Industrialactivitiesthatcanproducehydrogensulfide includepetroleum/naturalgasdrillingandrefining,wastewatertreatment, coke ovens, tanneries, and paper mills.In natural gas and crude oil, it is a contaminantthatmustberemovedbeforeproductsaresenttocommercial markets.Hydrogen sulfide can be dissolved in liquids and may be released by agitation, depressurization, or heating.Since hydrogen sulfide is heavier than air, it will collect in low places. Refer to Appendix A for additional leak and hazard information. Hydrogen sulfides offensive odor is readily detect-ableatverylowconcentrations.However,smell cannotbereliedupontoforewarnofdangerous concentrationsbecauseitrapidlydegradesthe senseofsmellduetoparalysisoftheolfactory nerve. A longer exposure to lower concentrations hasasimilardesensitizingeffectonthesenseof smell. Exposure to relatively low levels of hydro-gen sulfide can be fatal. The physical effects of vari-ous concentration levels are shown below. ppmPhysical Effects1Can be smelled (rotten egg odor) 10Obvious and unpleasant odor(Permissible 8 hour exposure levelOSHA)50Loss of sense of smell in 15 minutes(10 minute exposure level once only if no other measurable exposureoccursOSHA)100Loss of smell in 315 minutes, stinging in eyes and throat, altered breathing(Immediately Dangerous to Life and HealthOSHA)500Unconscious quickly, death will result if not rescued promptlyNOTE The range of flammable limits for H S (4 percent to 44 percent2in air by volume) is much greater than the range of flammable limits fornatural gas (4 percent to 16 percent).17 2022 by Pipeline Association for Public Awareness'