Approved
January 2013
Approved by: President James L. Price, Jr.
Reaffirmed
June 2025
I. Purpose
To establish guidelines for air monitoring at structure fires.
II. Policy
This guideline applies to all Kent County, MD. Fire/EMS/Rescue Companies.
III. Guideline
Fire, smoke and its many bi-products of combustion present a serious health risk to
responders. Hydrogen Cyanide (HCN) and Carbon Monoxide (CO) are just a few of the
deadly gases that when exposed to can pose immediate and long-term health effects. HCN is
produced when materials such as insulation or synthetic materials are burned or heated. The
symptoms closely mirror those of carbon monoxide exposure; therefore, personnel must be
cognizant of its presence.
Vehicle fires and trash fires also generate high levels of HCN and CO, but because they
normally occur in an open environment the products of combustion dissipate quickly into the
atmosphere. However, when smoke is present the need for SCBA is vital for responder
protection.
IV. Safety
A. Safety of responders is the first priority, therefore SCBA are required until safe
atmosphere can be determined by the use of meters.
B. HCN exposure may be difficult to determine. Its symptoms are similar to that CO exposure, which may include headache, nausea, fatigue and dizzy spells at low levels and respiratory problems, unconsciousness, and cardiac arrest for high levels. If exposure is suspected transport to a health care facility should not be delayed.
V. Personal Protective Equipment
A. Self Contained Breathing (SCBA)
1. SCBA is the best preventive measure for smoke exposure, as inhalation is the primary
route of entry for exposure.
2. SCBA is required on all structure fires that present a smoke condition, to include
kitchen and cooking fires, until monitoring has taken place.
3. SCBA is required on all vehicle fires until completely extinguished and all smoke as
dissipated, or monitoring has taken place.
4. SCBA is required on all large trash receptacle fire until completely extinguished and all
smoke has dissipated.
B. Structural Turnout Gear
1. Turnout gear helps protect personnel from absorbing smoke, including HCN and CO
through the skin, which is a secondary route of exposure.
2. Personnel are should wash turnout gear following structure fires that heavily soil and
saturate gear with products of combustion.
VI. Monitoring
A. All structure fires are to be monitored by utilizing HCN and CO meters.
B. If a company with meters is not on scene the Incident Commander (IC) is to request a unit with a meter to respond.
C. Companies that have an HCN and CO meter are to turn on the meter and leave it at the Command Post to ensure its usage by the IC, RIT, and/or companies in staging.
D. SCBA are not to be removed until the atmosphere can be monitored and deemed safe.
E. The following conditions will warrant atmospheric monitoring.
1. When SCBA have been used during a working structure fire, ventilation is complete,
and the removal of SCBA is requested.
2. Any personnel are found operating inside the structure without SCBA.
a. The HCN meter is to be used immediately in the area where crews were found to be operating.
b. The HCN and CO level is to be communicated to the IC along with personnel who were found to be operating in the area.
c. The IC must determine the length of time the personnel were operating in the environment without SCBA, and the reported readings.
d. If readings and operating time period is of sufficient length and signs of exposure exist, then personnel are to be transported to the hospital for immediate evaluation (see section VII.A.)
3. Vehicle fires within a structure or in a parking garage.
4. Whenever deemed necessary by the IC.
5. Adjacent apartments or structures where smoke is reported.
F. The following conditions will not warrant atmospheric monitoring. This does not dismiss the need for SCBA, and if a meter is readily available monitoring is still encouraged.
1. Vehicle fires in the open atmosphere.
2. When burning order is detected and there is no visible smoke i.e. light ballast.
VII. Action Levels
A. The action level in order to operate without SCBA in an environment where HCN is present will be 5ppm (4.7ppm). This is the Short-Term Exposure Limit (STEL) for HCN as recommended by NIOSH.
1. STEL as defined by NIOSH is a 15-minute TWA (Time-Weighted Average) exposure
that should not be exceeded at any time during the workday.
2. Immediately Dangerous to Life and Health (IDLH) for HCN is 50ppm
B. The action level for CO will be 35ppm. The atmosphere must meet both the action level for HCH and CO in order for personnel to operate without SCBA.
VIII. Decontamination
A. Personnel should practice good personnel hygiene by washing hands prior to drinking and eating in rehab or back at the station.
B. If turnout gear has readings higher than 5ppm of HCN decontaminate the gear.
1. Use a PPV fan to blow off large particulates on the gear, and if needed use a soft
bristle brush.
2. If a fan is not available briefly rinse with a soft fog pattern to prevent saturation.
3. All personnel operating inside the structure should be decontaminated.
C. Gear should be washed as soon as possible in an approved gear extractor.
1. Turnout gear, flash hood, and helmet ear flaps should be washed in extractor.
2. Gloves should be washed by hand with a hose or in sink.
D. If a gear extractor is unavailable, then a garden hose and brush can be used. Allow gear to dry out of direct sunlight.
IX. Reporting
A. The reporting officer will be responsible for recording any significant exposures during a structure fire.
B. The following information will be supplied in narrative
1. The HCN and CO levels during the time of operation.
2. Areas monitored with corresponding reading.
3. How long personnel operated in the atmosphere.
4. The personnel operating in the hazardous atmosphere.
5. Specifics concerning the call. i.e. major materials that burned or were greatly heated.
C. Exposure reporting
1. Anytime personnel are operating outside the safe range without SCBA a notation is to
be made in the NFRIS report under Fire Personnel Causality section.
X. Exposure
A. The following three indicators are to be used to determine if a person has been exposed to HCN.
1. Exposed to fire or smoke in an enclosed area.
2. Soot found around the mouth and nose.
3. Altered mental status.
B. Hydrogen cyanide can cause rapid death due to metabolic asphyxiation. Death can occur within seconds or minutes of the inhalation of high concentrations of hydrogen cyanide. Sources report that 270ppm is fatal after 6 to 8 minutes, 181 ppm after 10 minutes and 135 ppm after 30 minutes. These levels were not uncommon during routine structure fires.
C. Acute exposure symptoms including weakness, headache, confusion, vertigo, fatigue, anxiety, dyspnea, and occasionally nausea and vomiting. Respiratory rate and depth are usually increased initially, and later stages become slow and gasping. Coma and convulsions occur in some cases. If cyanosis is present, it usually indicates that respiration has either ceased or has been inadequate for a few minutes. If large amounts of cyanide have been absorbed, collapse is usually instantaneous; unconsciousness; often with convulsion, is followed almost immediately by death.
D. If personnel are found to have been operating in an IDLH atmospheres or experiencing severe health effects, it is strongly recommended they be transported for advance medical evaluation. The safety officer that reports to hospital is to request the following;
1. HCN has a half-life of one hour, therefore it is imperative that the exposed personnel
be given immediate medical attention to include blood work and for tested for HCN
levels in the blood.
2. It is important that when transported the hospital be advised that the firefighter was
operating in a known hazardous environment containing hydrogen cyanide.
Betterton Volunteer Fire Company, Inc.
Chief Renny Grapes
YES NO NOT PRESENT
Chestertown Volunteer Fire Company, Inc.
Chief John Darling
YES NO NOT PRESENT
Community Volunteer Fire Company of Millington, Inc.
Chief Charles Boyles
YES NO NOT PRESENT
Galena Volunteer Fire Company, Inc.
Chief Albert (Bert) Piasecki, Jr.
YES NO NOT PRESENT
Kennedyville Volunteer Fire Department, Inc.
Chief James L. Price, Jr.
YES NO NOT PRESENT
Kent & Queen Anne’s Rescue Squad, Inc.
Chief Jason Lobley
YES NO NOT PRESENT
Rock Hall Volunteer Fire Company, Inc.
Chief Mike Pinder
YES NO NOT PRESENT
Kent County Emergency Service Board
Chair Lynn Sutton
Submitted for Emergency Service Board Approval on ____July 21st, 2025______________
Compliance Date _______August 19th, 2025________________________________________