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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.

References:

Category
Firefighter Health and First Aid

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NWCG Latest Announcements

Leadership Committee IAP Flyer Now Available

Date:  May 8, 2026
Questions? 
Please contact: Leadership Committee

The NWCG Leadership Committee promotes and enables leadership development across the wildland fire service. The committee provides education, training opportunities, and support for leadership innovation and best practices throughout the community.

A new IAP flyer is now available on the committee website, offering an overview of the products, curriculum, and learning opportunities the Leadership Committee develops. This resource is ideal for posting in your office, sharing with new employees, or distributing through your incident management teams to engage new voices in the leadership journey and reinforce a culture of self‑reflection, development, and growth.

References:

Leadership Committee 2026 IAP Flyer

Incident Operations Subcommittee Updates the Next Generation Position Task Book for FFT1

Date:  May 7, 2026
Questions? 
Please contact: Incident Operations Subcommittee

The NWCG Incident Operations Subcommittee (IOSC) has updated the NWCG Position Task Book for Firefighter Type 1 (Squad Boss) (FFT1), PMS 311‑14. The FFT1 Position Task Book transitioned to the Next Generation (Next Gen PTB) format in June 2025 through the Incident Performance and Training Modernization effort. Since then, IOSC has received feedback from the wildland fire community regarding coding for one of the tasks. Task #13 has been updated to include the option of evaluation in a simulation.

See IOSC Memorandum 26‑01: Transition Plan for Implementation of Updates to the NWCG Position Task Book for Firefighter Type 1 (Squad Boss) (FFT1), PMS 311‑14 for more information.

References:

IOSC Memorandum 26-01: Transition Plan for Implementation of Updates to the NWCG Postion Task Book for Firefighter Type 1

NWCG Firefighter Type 1 Squad Boss Position Page 

NEW! S-212, Intermediate Faller (Online) Course Available Now 

Date:  April 23, 2026
Questions? 
Please contact: Hazard Tree and Tree Felling Subcommittee

NWCG is pleased to announce that the new S‑212, Intermediate Faller (Online), course is now available on the Wildland Fire Learning Portal (WFLP). This second course in the series provides students with the knowledge and skills required to perform the duties of an Intermediate Faller (FAL2), as described in the FAL2 Incident Position Description. This course is intended for individuals seeking to advance from Basic Faller (FAL3) to FAL2.

S‑212, Intermediate Faller is a fully online, self‑paced training program consisting of 13 units. Learners will engage with interactive, scenario‑based content designed to progressively build foundational skills and knowledge essential for the FAL2 role.

Students must be qualified as a Basic Faller (FAL3) prior to enrolling in S‑212, Intermediate Faller course.

Any changes to qualification pathways will take effect with the next update of the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1, scheduled for January 2027.

References:

S-212 Intermediate Faller (Online)

RMC Memo 26-01: Transition Plan for Implementing Updates to Intermediate Faller (FAL2) Position Qualifications

Intermediate Faller (FAL2) Position Page

NWCG Standards for Wildland Fire Chainsaw Operations, PMS 212

New Aircraft Flight Schedule Form, PMS 249

Date:  April 17, 2026
Questions? 
Please contact: National Coordination System Committee

A new publication from the National Coordination System Committee (NCSC) is now available. The NWCG Aircraft Flight Schedule Form, PMS 249, will be used for aviation crews and dispatch to share flight information that is needed for resource tracking, and if needed, for emergency procedures.

For further details, please contact your NCSC representative. 

References:

NCSC Memo 26-01: Implementation of NWCG Aircraft Flight Schedule Form, PMS 249

NWCG Aircraft Flight Schedule Form, PMS 249