Skip to main content

6MFS

6MFS Committee

All 6MFS Topics

6MFS Calendar

Aviation

Airtankers

Felling Safety

Fire Communication

Firefighter Health & First Aid

Leadership

Misc Fireline Hazards

Operational Engagement

This Day in History

Vehicles - Roads

Weather - Fire Behavior

Week of Remembrance

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.

 

Category
Firefighter Health & First Aid
References
Maverick Lessons Learned Review
NWCG Incident Response Pocket Guide, PMS 461
Interagency Standards for Fire & Fire Aviation Operations (Red Book)

6MFS Suggestion Form


Have an idea or feedback?

Share it with the NWCG 6MFS Subcommittee
 


Follow NWCG on X and Facebook
 


 

Last Modified / Reviewed:

Print PDF

NWCG Latest Announcements

NEW! S-130, Firefighter Training (Blended) Now Available

Date: June 10, 2025
If you have questions, please visit our FAQ page. 
If your question is not answered there, you can 
submit your question using our Contact Us form. 
 

The S-130, Firefighter Training (Blended), equips new wildland firefighters with essential skills through a mix of online learning and hands-on training. The course features a required online component and an instructor-led exercise, reinforcing online concepts with practical performance-based training.

The course builds competencies in wildland fire operations, safety, and equipment use, applicable across various operational environments. Both the online component and instructor-led field exercise must be completed to receive a certificate of completion. Students are required to finish the prerequisite S-190, Introduction to Wildland Fire Behavior, before enrolling in S-130, Firefighter Training (Blended).

References:

S-130, Firefighter Training (Blended)

S-190, Introduction to Wildland Fire Behavior

Wildland Fire Learning Portal

EMC Memo 25-001: Interim Rapid Extraction Module (REMS) Training and Qualification Requirements

Date: June 3, 2025
Questions?  Please contact:
Emergency Medical Committee

The Emergency Medical Committee has issued interim guidance for Rapid Extraction Module Support (REMS) teams. Until further notice, Type I and II REMS teams must designate a team leader qualified at Firefighter Type 1 Squad Boss (FFT1) or higher. This temporary change replaces the Single Resource Boss (SRB) requirement, which is currently not feasible due to administrative barriers.

This memorandum does not include any other changes to the NWCG Standards for Rapid Extraction Module Support, PMS 552. This interim change takes effect immediately and will remain in place until further notice.

References:

EMC Memo 25-001: Interim Rapid Extraction Module (REMS) Training and Qualification Requirements

NWCG Standards for Rapid Extraction Module Support, PMS 552

Equipment Bulletin 25-002: Chaps, Chain Saw, M-2020, Nonconformities Affecting Use, Appearance, and Serviceability

Date: June 2, 2025
Questions?  Please contact:
Equipment Technology Committee

The Equipment Technology Committee issued Equipment Bulletin: 25-002 to address a manufacturing nonconformity affecting Forest Service specification, 6170-4K Chain Saw Chaps. The issue applies to chaps manufactured in 2024 and 2025 and distributed through FedMall. These chaps may have incorrectly bound edges that expose inner protective layers.

Independent purchasers should inspect all chain saw chaps received from FedMall beginning in 2024, prior to use. Review the full Equipment Bulletin: 25-002 for inspection criteria and recommended actions.

References:

NWCG Alerts

ETC Equipment Bulletin: 25-002

2024 Wildland Fire Emergency Medical Service Awards

Date: May 22, 2025
Questions?  Please contact:
Emergency Medical Committee

The NWCG Emergency Medical Committee (EMC) is proud to announce the recipients of the 2024 Wildland Fire Emergency Medical Service Awards. Each year, EMC recognizes individuals and groups who have demonstrated exceptional actions or accomplishments that go above and beyond their normal mission or job duties.

Congratulations to all the awardees and nominees. Through leadership and initiative, they have made significant contributions to the safety and well-being of the wildland fire community. These honors are well deserved.

References:

2024 Wildland Fire EMS Awards

NWCG Emergency Medical Committee