Hoffman Estates Fire Department Hydrogen Cyanide Monitoring PDF

HOFFMAN ESTATES FIRE DEPARTMENT STANDARD OPERATING GUIDELINES SOG Category & Identification Number: EFFECTIVE DATE: SAFETY OPERATIONS - 012 January 1, 2022 NIMS COMPLIANT SOG Titl...

HOFFMAN ESTATES FIRE DEPARTMENT STANDARD OPERATING GUIDELINES SOG Category & Identification Number: EFFECTIVE DATE: SAFETY OPERATIONS - 012 January 1, 2022 NIMS COMPLIANT SOG Title: Hydrogen Cyanide Monitoring Revision: 5 APPROVED BY: NUMBER OF PAGES: Re-evaluation Date: Alan Wax January 1, 2025 Fire Chief 4 PURPOSE To establish a guideline for monitoring the atmosphere for hydrogen cyanide at structure fires or other incidents deemed necessary. POLICY It shall be the policy of the Hoffman Estates Fire Department to monitor the atmosphere for hydrogen cyanide at structure fires or other incidents where it may be present. PROCEDURE Hydrogen cyanide (HCN) is a deadly gas and bi-product of combustion present at nearly every structure fire. It is produced when materials such as insulation or synthetics are burned or heated. HCN has been known to be a product of combustion, but just recently has its significance been acknowledged. The symptoms closely mirror those of carbon monoxide exposure; therefore personnel must be cognizant of its presence. Vehicle fires also generate a high level of HCN, 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. I. Safety a. Safety of responders is the first priority; therefore SCBA use is required until a safe atmosphere can be determined. b. Hydrogen cyanide exposure may be difficult to determine. Its symptoms are similar to that of carbon monoxide exposure, which may include headache, nausea, fatigue and dizzy spells at low levels and respiratory problems, unconsciousness, and cardiac arrest at high levels. c. Hydrogen cyanide is a combustible gas and should be treated with caution. 1 II. Properties a. NIOSH describes the appearance and odor of HCN as a colorless gas or bluish-white liquid with a bitter almond odor. An air odor threshold concentration for hydrogen cyanide of 0.58 ppm has been reported. b. The most common environment likely to possess HCN is a structure fire. The common appearance and odors associated with hydrogen cyanide will be severely masked by smoke. c. HCN is lighter than air and will rise in the heated atmosphere of a structure fire. In an enclosed environment without ventilation, vapors will linger. III. Personal Protective Equipment a. Self-Contained Breathing Apparatus (SCBA) 1. SCBA is the best preventive measure for HCN exposure, as inhalation is the primary route of entry for exposure. 2. SCBA is required on all structure fires that present a smoke condition including kitchen and cooking fires or as directed by the Incident Commander. 3. SCBA is required on all vehicle fires until completely extinguished and all smoke has dissipated. b. Structural Turnout Gear 1. Turnout gear helps protect personnel from absorbing HCN through the skin which is a secondary route of exposure. 2. Personnel should wash turnout gear that is heavily soiled and saturated with the products of combustion following firefighting activities. IV. Monitoring a. All structure fires shall be monitored utilizing one of the approved HCN meters. This will not replace the current practice of monitoring for carbon monoxide levels, but shall be conducted concurrently. b. Meters will be stored on Tower 22. c. SCBA use shall not be discontinued until the atmosphere can be monitored and deemed safe. If an operational HCN is not available at the scene and personnel will be operating for an extended period of time SCBA shall be used. d. The following conditions will warrant atmospheric monitoring: 1. When SCBA has been used during a working structure fire, ventilation is complete and the removal of SCBA is requested. 2. When 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 level is to be communicated to the Incident Commander along with information about personnel who were found to be operating in the area. 2  c. The Incident Commander must then determine the length of time the personnel were operating in the environment without SCBA, and the reported readings. d. If readings of greater than 10 ppm and exposure time period are greater than 15 minutes, personnel are to be transported to the hospital for immediate evaluation. 3. Vehicle fires within a structure or in a parking garage. e. The following conditions will not warrant atmospheric monitoring. 1. When the fire is contained to the cooking container where only food has burned and no damage was caused to the container. 2. Vehicle fires in the open atmosphere. 3. When a burning odor is detected and there is no smoke visible or only a light haze. V. Action Levels a. Hydrogen cyanide is thirty five times more dangerous than carbon monoxide. Because of this the action level for HCN is lower than CO. The action level in order to operate without SCBA in an environment where HCN is present will be 4.7 ppm. This is the NIOSH recommended airborne exposure limit (REL), which should not be exceeded at any time. b. 1. STEL as defined by NIOSH is a 15-minute TWA (Time-Weighted Average) exposure that should not be exceeded at any time during a workday. 2. Immediately Dangerous to Life and Health (IDLH) for HCN is 50 ppm. c. The action level for carbon monoxide will remain the same at 35ppm. The atmosphere must be below the action level for both HCN (4.7 ppm) and CO (35 ppm) in order for personnel to operate without SCBA. VI. Decontamination a. Personnel should practice good personal hygiene by washing hands prior to drinking and eating in rehab. b. Once the incident is placed under control, a random selection of personnel known to have operated in the structure should have their PPE scanned with the hydrogen cyanide monitor. c. If turnout gear has a reading higher than 4.7 ppm; a hose line is to be used to rinse off the gear. In inclement weather, gear is to be taken out of service and washed per department policy. VII. Reporting Anytime personnel are operating outside the safe range (above 4.7 ppm) without SCBA; annotation is to be made in the Firehouse (NFIRS) report. VIII. Calibration a. Meters shall be calibrated every 90 days (per manufacturer recommendations). 3  b. If meters are exposed to a high concentration and register “out of range” on the LED display, the meter will need calibration. IX. Exposure a. 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 270 ppm is fatal after 6 to 8 minutes, 181 ppm after 10 minutes and 135 ppm after 30 minutes (Hathaway et al, 1991). b. 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 at 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 convulsions, is followed almost immediately by death (Hathaway et al, 1991). c. If personnel are found to have been operating in IDLH atmospheres or experiencing severe health effects, it is strongly recommended they be transported for advanced medical evaluation. 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 tested for HCN levels in the blood. 2. Because this is somewhat new information, it is likely test results will be delayed, but personnel will still be treated and monitored by advanced medical personnel. 3. It is important that when transporting, the hospital be advised that the firefighter was operating in a known hazardous environment containing hydrogen cyanide. DEFINITIONS EXCEPTIONS Where MABAS Illinois Policies and Procedures current online reference or MABAS 1 Operating Guidelines/Policy Statements are in conflict with HEFD Standard Operating Guidelines, HEFD Standard Operating Guidelines will take precedence. REFERENCES MABAS Illinois Policies and Procedures current online reference MABAS 1 Operating Guidelines/Policy Statements Dudley HC, Sweeney TR, Miller JW. Toxicology of acrylonitrile (vinyl cyanide). II. Studies of effects of daily inhalation. J Ind Hyg Toxicol 23:255-258. Flury F, Zernik F. Schädliche gase dämpfe, nebel, rauch- und staubarten. Berlin, Germany: Verlag von Julius Springer, p. 404 (in German). Hathaway GJ, Proctor NH, Hughes JP, and Fischman ML. Proctor and Hughes' chemical hazards of the workplace. 3rd ed. New York, NY: Wiley and Sons. Patty FA, ed.. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., 1988 United States Department of Labor End of Document 4