Hydrogen Sulfide Gas (H²S)

Hydrogen sulfide (also known as H²S, sewer gas, swamp gas, stink damp, and sour damp) is a colorless gas known for its pungent "rotten egg" odor at low concentrations. It is extremely flammable and highly toxic. Oil and gas production across the western United States has increased dramatically and can have an impact on fire suppression operations and expose fire personnel to health hazards. Naturally occurring coal seams can produce potentially toxic gases as well.
Hydrogen sulfide is used or produced in a number of industries, such as:

• Oil and gas refining
• Mining
• Tanning
• Pulp and paper processing
• Rayon manufacturing

Hydrogen sulfide also occurs naturally in sewers, manure pits, well water, oil and gas wells, and volcanoes.
At higher concentrations, H²S can result in respiratory paralysis, asphyxia, seizures, and death. Characteristics of a significant exposure are rapid knock down, respiratory depression, tremors, blurred vision, cyanosis, seizures, and elevated heart rate. H²S vapor can also travel considerable distances to a source of ignition and flash back explosively, giving off corrosive, and poisonous oxides of sulfur upon combustion.

To avoid exposure to H²S, here are some DO’s and DON’Ts concerning fire operations near oil and gas operations:

Do's:

• If you are responding to a known oil and gas pad or coal seam areas, DO contact local petroleum engineer or resource advisor.
• If your unit has known oil and gas operations or coal seams, DO ensure that every firefighter is provided with training on H²S.
• If you happen upon a remote oil and gas pad area, DO cordon off the area with flagging, deny entry, and modify suppression tactics to avoid the area.
• DO avoid low-lying drainages, ravines, and gullies near oil and gas pads and coal seams as they tend to accumulate higher air concentrations of potentially toxic gases, especially during early morning hours when air has the tendency to sink.
• If you suspect that someone has been exposed to H²S, DO seek medical care immediately at the nearest hospital.

​Don'ts:

• DON’T locate fire camps, Incident Command Posts (ICP), or helispots on, or near oil and gas pads.
• DON’T depend on sense of smell for warning – H²S causes rapid deterioration of sense of smell.
• DON’T attempt fire suppression on or near oil and gas pads. Local petroleum engineers or resource advisors may recommend safe working distances, and firefighters may also be given H²S monitors when working near oil and gas pad operations and/or coal seams.
• DON’T wait to seek medical attention if H²S exposure is suspected.