Fighting Today’s Fires Fires are decreasing over the years Advancement in firefighter equipment NFPA Study –1970 the ratio was 1.8 death per 100,000 fires –2000 the ratio is 3.0 per 100,000 fires * Fahj, Rita Fire Service fatalities in Structure Fires. 1977-2009 NFPA qurvey MA June 2010
Fighting Today’s Fires Legacy vs. modern http://www.youtube.com/watch?v=aDNPh q5ggoE
The Fuels changed and so did the smoke Partial List of Fire Produced Gases and Vapors Carbon Monoxide Carbon Dioxide Hydrogen Cyanide Hydrogen Chloride Nitrous Gases Phosgene Hydrogen Sulfide Sulfur Dioxide Acrolein Ammonia Formaldehyde Glutaraldehyde Acetaldehyde Benzaldehyde Benzene Various PNAs
Historically, carbon monoxide asphyxiation has been considered the primary cause of deaths of those overcome by smoke –Focus of gas monitoring There is mounting evidence that hydrogen cyanide is directly responsible for many more deaths than previously assumed –Cumulative effect with CO worse than either individually The Fuels changed and so did the smoke
Hydrogen Cyanide (HCN) Hydrogen Cyanide in Smoke
Cyanide production in a fire Hydrogen cyanide is produced by incomplete combustion of nitrogen and carbon containing substances (H-C≡N) Natural fibers (wool, silk, cotton, paper) Synthetic polymers (nylon, polyurethane) Synthetic rubber Melamine (resins for molding, laminating, etc.) Hydrogen Cyanide (HCN)
HCN RELEASING POLYMERS Synthetic polymers found extensively in structures Insulation Cushioning Carpets Bedding (mattresses and pillows) Building materials Materials can burn up to 2-3 times hotter and faster than natural materials Quicker flashovers increase speed of HCN release Hydrogen Cyanide (HCN)
Two independent studies performed on CN toxicity Paris France (1988-89) 109 fire victims( 66 survivors and 43 fatalities) 114 controlled individuals(drug intoxication, CO poisoning, major trauma) Dallas County Texas 144 smoke inhalation patients at University of Texas Health Science Center Emergency Department 43 deceased individuals at Dallas County medical examiners office. The New England Journal of Medicine Vol. 325 No. 25 Dec. 19, 1991 Hydrogen Cyanide (HCN)
Most notorious incident of deaths from toxic mix of hydrogen cyanide and carbon monoxide was at West Warwick, Rhode Island nightclub fire Feb 20,2003 Pyrotechnics instantly set substandard sound suppressing foam to sheet of flame HCN and CO levels soar and people are quickly overcome by the smoke 462 occupants in attendance 100 deaths and 200 injuries Hydrogen Cyanide (HCN)
Thursday March 23 2006 10:31 hrs 1197 Broad Street Providence Rhode Island Firefighters responded to a fast food restaurant relatively uneventful. Hydrogen Cyanide (HCN)
Engine 3’s crew member experienced symptoms of headache, dizziness, difficulty breathing a cough, and at times talking incoherently. Transported to Rhode Island Hospital Level 1 Trauma Center. Tested for HCN to find high levels of blood cyanide at 57 ug/dl Placed on antidote therapy Upon learning of Engine 3’s firefighter department contacted all members responding to the call 16 members sought medical attention. 14 members went to Rhode Island Hospital 4 found to have whole blood cyanide levels above 20 ug/dl Hydrogen Cyanide (HCN)
March 24, 2006 02:07 Hrs. 70 Ralph Street Providence firefighters responded to a kitchen fire in a two story occupied dwelling. Fire apparently started in bathroom. All firefighters responding had previously responded to the Knight Street fire. 02:23 hrs Firefighter Kenneth Baker collapsed suffering a heart attack. Hydrogen Cyanide (HCN)
In light of the cyanide cases from the previous day testing was conducted on Firefighter Baker. Lab test showed that FF. Baker had whole blood cyanide level of 66ug/dl After consulting with doctors at Rhode Island Hospital, all members who responded to any of the three fires were instructed to go to Rhode Island Hospital if they experienced any symptoms to cyanide poisoning. 28 members sought medical care 27 had their cyanide levels tested 8 members tested high (above 20 ug/dl) for cyanide Fire Chief David Costa appointed a five member committee to investigate the causes of cyanide poisoning, review existing policies and procedures, and make recommendations to prevent this from happening again. Hydrogen Cyanide (HCN)
Hydrogen cyanide is a cellular asphyxiate. - Inhaled HCN has a high affinity for a key enzyme cytochrome c oxidase in the aerobic respiratory pathway. - Sufficient quantities shuts down the aerobic pathway at the sub- cellular (mitochondia) level leaving cells to rely on anaerobic respiration, resulting in lactic acidosis and other toxic substances in the tissues and organs. Carbon Monoxide is a cellular asphyxiate -Inhaled CO binds to the hemoglobin with an affinity 200-300 times that of oxygen, creating carboxyhemoglobin greatly reducing oxygen capacity.. -Binds to other enzymes, myoglobin, cytochrome oxidase. Accumulation of CO has a half-life of 2-5 hours as the concentration decreases. Effects of HCN
Hydrogen cyanide is a cellular asphyxiate. - Inhaled HCN has a high affinity for a key enzyme cytochrome c oxidase in the aerobic respiratory pathway - Sufficient quantities shuts down the aerobic pathway at the sub-cellular (mitochondia) level leaving cells to rely on anaerobic respiration, resulting in lactic acidosis and other toxic substances in the tissues and organs. There is no quick test that allows on-site confirmation of HCN toxicity There are some signs that can lead to assumption of HCN exposure and administration of countermeasures: - Disorientation, weakness, drowsiness - Shortness of breath/chest tightening - Headache - Bright red discoloration of skin - Smell of almonds on breath - Soot around mouth and nose/ burns - Carbonaceous sputum HYDROGEN CYANIDE IN FIRE OPERATIONS HEALTH EFFECTS
HCN Effects HYDROGEN CYANIDECARBON MONOXIDE Onset of signs and symptoms is rapid after inhalation. Headache Nausea Dizziness Difficulty breathing: -Simple removal to outside air or oxygen administration will not correct problem. Short term exposures include: Headache Dizziness Confusion Disorientation Memory Loss Fainting Seizures Difficulty breathing: -Simple removal to outside air or oxygen administration will help correct the problem.
HCN Effects There are some signs that can lead to assumption of HCN exposure and Administration of countermeasures: - Disorientation, weakness, drowsiness - Shortness of breath/chest tightening - Headache - Bright red discoloration of skin - Smell of almonds on breath - Soot around mouth and nose/burns - Carbonaceous sputum
HCN Effects HYDROGEN CYANIDE CARBON MONOXIDE Breathing problems: Respiratory depression/respiratory arrest Chest pain: cardiac arrhythmia to cardiovascular collapse Eye irritation to vision dimming Palpitations Headaches Loss of appetite Weakness in extremities to paralysis Enlargement of thyroid glands Cardiac complications Neurological Syndrome: memory loss, confusion, seizures, depression/anexity,hallucinations. Syncope Weakness Incontenence-uninary/fecal Coma Death
HCN Exposure Limits 0-15 seconds: Transient Hypernea 0-15 seconds: Transient Hypernea 6-8 minutes: Cardiac Arrest 30-45 seconds; Convulsions 2-3 minutes Respiratory Depression 060120180240 Increasing rate and depth of respiration Medical Management of Chemical Casualties Handbook
HCN effects Narcotic effects of HCN blamed for bizarre and irrational behavior instances where victims, including firefighters fought with rescuers until becoming totally overcome by the smoke.
Toxicity Concentrations mg/m3 ppm Effect 300 mg/m3 270 ppmImmediately Lethal 200mg/m3 180 ppmLethal after 10 minutes 150mg/m3 135 ppmLethal after 30 minutes 120-150mg/m3 108-135 ppmHighly dangerous (Fatal) after 30-60 minutes 20-40mg/m3 18-36 ppmLight symptoms after several hours
Toxicity Toxicity /Flammability ratio between HCN/CO 35 Times! HCN CO TWA 4.7 ppm 35 ppm IDLH 50 ppm 1200 ppm LEL 5.6% 12.5% UEL 40% 74%
Recommendations for protection against the toxic gases Removal of respiratory equipment during overhaul can potentially expose firefighters to a variety of toxic gases Overhaul phase of fire lasts an average of 30 minutes Liberated gases, vapors and particulates may remain in overhaul environment for extended periods of time Vapors may use airborne particulates as entry vehicle into firefighters’ lungs Maximum concentrations of selected contaminants can exceed occupational exposure limits Adverse health effects may occur from exposure to mixture of products even if individual components are below exposure limits Monitoring CO concentrations alone should not be used to predict presence of other contaminants found in the overhaul environment. Bolstad-Johnson, et al
Behavior Change Without the use of respiratory protection, firefighters are overexposed to irritants, chemical asphyxiates and carcinogens. Respiratory protection is recommended during fire overhaul SCBA should be utilized in atmospheres with CO > 150 ppm Post-fire fuels are still off-gassing, SCBA’s should be used. Cyanide
Break Time Further Questions ? 15 minutes break.
RECAP KEY POINTS WE WANT TO LEAVE YOU WITH How does HCN effect you? Cellular asphyxiate HCN- shuts down aerobic pathway creating lactic acidosis and other toxic substances in tissues and organs. CO- hemoglobin bonds 200-300 times that of oxygen. Half life 2-5 hours as concentration decreases Acute exposures- Disorientation, weakness, headaches, fainting Chronic exposures- respiratory, cardiac,neurological syndrome, enlargement of thyroid glands
KEY POINTS WE WANT TO LEAVE YOU WITH How to protect yourself ? Be Aware, Use Your Air! Atmospheric Monitoring Gas Detection Post Fire decontamination – Including Nomex hoods Department wide education as to the awareness of HCN and CO.
HCN CO Part II Think “Working towards the safety of tomorrows firefighters today.”
HCN CO Part II DISCLAIMER: Tests were conducted according to NFPA 1403 “Standards on Live Fire Training Evolutions utilizing Florida Certified Live Fire Instructors and Certified Fire Videographer. Atmospheric air monitoring application taught through division of State Fire Marshall Florida State Fire College Minimum Standards since 2007. Atmospheric instrumentation gas calibrated day of testing.
BASIC FIRE BEHAVIOR 101 OBJECTIVES OF FIRE DYNAMICS IS TO DEVELOP HOW FIRE : DEVELOPS GROWS SPREADS FIRE IS AN EXOTHERMIC OXIDATIVE REACTION THAT PROCEEDS AT SUCH A RATE THAT IT GENERATES DETECTABLE HEAT AND LIGHT. IN ORDER FOR FIRE TO OCCUR IT MUST HAVE: 1.Combustible fuel present 2.An oxidizer(such as oxygen in the air) must be available in sufficient quantity. 3.Energy as some means of ignition( heat) must be applied. 4.The fuel and oxidizer must interact in a self-sustaining chain reaction. HEAT IS TRANSFERRED IN THREE FUNDAMENTAL WAYS: CONDUCTION CONVECTION RADIATION ENERGY THROUGH MATERIAL CIRCULATING/MOVING ELECTROMAGNETIC WAVES HCN CO Part II
Fire Development in a Compartment Basic Fire Behavior 101 Fire in an unconfined area, heat produced dissipates into atmosphere through radiation and convection. Outdoor fires typically have enough oxygen only limiting factor is the fuel. HCN CO Part II
Fire Development in a Compartment Basic Fire Behavior 101 Fire within a confined area – walls, ceiling, floors, and other objects absorbs radiant heat by fire Radiant heat not absorbed is reflected back continuing to increase temperatures of the fuel and rate of combustion HCN CO Part II
Fire Development in a Compartment Basic Fire Behavior 101 Hot smoke / air becomes more buoyant Contact with cooler materials, heat conducted, raising temperature Transfer process raises temperature of all materials Nearby fuel is heated, begins to pyrolize, causing fire extension
HCN CO Part II Fire Development in a Compartment Basic Fire Behavior 101 Sufficient oxygen within compartment Fire development is controlled by the characteristics and configured of the fuel, said to be fueled controlled!
HCN CO Part II Fire Development in a Compartment Basic Fire Behavior 101 Insufficient oxygen within a compartment Reaches a point where fire becomes limited by the available air supply, said to be ventilation controlled!
HCN CO Part II Fire Development in a Compartment Basic Fire Behavior 101 Fire has not yet influenced environment to a significant extent Temperature only slightly above ambient, concentration of products of combustion low Radiant heat warms adjacent fuel and continues the process of pyrolysis Hot gases and fire spread horizontally across ceiling and conducts heat to other materials increasing overall temperatures Transition to growth happens quickly INCIPIANT PHASE
HCN CO Part II Fire Development in a Compartment Basic Fire Behavior 101 GROWTH PHASE Fire influences environment within compartment by configuration and amount of ventilation Ceiling and walls affect the plume of hot gases rising from the fire Unconfined fires draw air from all sides, entertainment for air cools the plume of hot gases rising from the fire reducing flame length and vertical extension
HCN CO Part II Fire Development in a Compartment Basic Fire Behavior 101 FULLY DEVELOPED Energy release is at maximum rate is limited only by availability of fuel and oxygen. Hottest phase of fire and the most dangerous for anybody trapped within.
HCN CO Part II Fire Development in a Compartment Basic Fire Behavior 101 DECAY STAGE Fuel is consumed and energy release diminishes, and temperature decreases Products continue to pyrolyze to form carbon monoxide and other gaseous fuel as well as toxic gases, solid soot, liquid aerosols, and other fuels in the form of smoke During this stage, fire goes from ventilation controlled to fuel controlled
HCN CO Part II Atmospheric Air Monitoring Is it Really Necessary? Hazardous Materials Response All aspects of today’s fires are Hazardous Materials Response! Your nose and lungs are not a good indicator to determine a safe environment 4 gas monitors can provide a false sense of security, if only CO and O2 are with acceptable levels
HCN CO Part II Atmospheric Air Monitoring Why Should We Deploy It? Tactical use for zoning of HOT ZONE for protection of Incident Commander and others at the fire scene It should be deployed during all 4 phases of fire
HCN CO Part II Atmospheric Air Monitoring Here’s the Reason Why! OSHA’s 29CFR 1910.134 Paragraph (d)(1)(iii) states: “The employer shall identify and evaluate the respiratory hazard(s) in the workplace; this evaluation shall include a reasonable estimate of employee exposure to respiratory hazards and an identification of the contaminant’s chemical state and physical form. Where the employer cannot identify or reasonably estimate the employee exposure, the employer shall consider the atmosphere to be Immediately Dangerous to Life and Health (IDLH)”. IDLH is defined as one that “poses an immediate threat to life, would cause irreversible adverse health effects, or would impair an individual’s ability to escape from a dangerous atmosphere.”
HCN CO Part II Atmospheric Air Monitoring But, Keep This in Mind… Based on knowledge of the potential range of “unknown products” of combustion during a structure fire and with limited means of ability to evaluate respiratory hazards, it may be correct to say that all phases of a structure fire have the potential to produce an IDLH atmosphere. If this is the case, then the only remedy allowed by OSHA is an atmosphere- supplying respirator, meaning, “a respirator that supplies the respirator user with breathing air from a source independent of the ambient atmosphere, and includes supplied air respirator (SAR’s) and self contained breathing apparatus (SCBA) units” as found in 29 CFR 1910.134(b) &(d)(2)(i). This would negate the use of filter masks, as well as air purifying respirators since neither provides “breathing air from a source independent of the ambient atmosphere.”
HCN CO Part II Example of Toxic Reading Incipient Phase LEL 0.0 OXYGEN 20.9 HCN 1.7 H 2 S 0.0 CO 14 Fuel consisted of wood cribbing
HCN CO Part II Example of Toxic Reading Growth Phase LEL 0.0 OXYGEN 20.9 HCN 2.3 H 2 S 0.0 CO 24 Fuel consisted of wood cribbing
HCN CO Part II Example of Toxic Reading Fully Developed Phase LEL 0.0 OXYGEN 20.3 HCN 2.8 H 2 S 9.0 CO 46 Fuel consisted of wood cribbing, microfiber recliner, synthetic rug, wooden coffee table, 12” x 12” x 10” polyurethane foam cushion
HCN CO Part II Example of Toxic Reading Decay Phase LEL 0.0 OXYGEN 00.0 HCN 0.0 H 2 S 0.0 CO 70 PPM Fuel consisted of wood cribbing, microfiber recliner, synthetic rug, wooden coffee table, 12” x 12” x 10” polyurethane foam cushion NOTE: THESE READINGS WILL NOT DEPICT YOUR ATMOSPHERIC AIR MONITOR RESPONSES TO THIS TYPE OF FIRE.
HCN CO Part II Example of Toxic Reading Permeation of Smoke Through PPE LEL 0.0 OXYGEN 00.0 HCN 3.9 H 2 S 0.0 CO 0 Fuel consisted of wood cribbing, microfiber recliner, synthetic rug, wooden coffee table, 12” x 12” x 10” polyurethane foam cushion
HCN CO Part II Example of Toxic Reading “Off-Gasing” Gear LEL 0.0 OXYGEN 00.0 HCN 1.3 H 2 S 0.0 CO 0 NOTE: THESE READINGS WILL NOT DEPICT YOUR ATMOSPHERIC AIR MONITOR RESPONSES TO THIS TYPE OF FIRE. - Off gasing gear in apparatus or personal vehicles upon completion of the fire - Off gasing gear within the bay of the fire station, permeating into other gear close by
HCN CO Part II Washer extractors wash frequently according to: NFPA 2008 requirements Manufacture specifications Department S.O.P’S Negative pressure decontamination on scene Electric fans to purge toxic contaminants from the inside out of turnout gear. DO NOT USE GAS DRIVEN FANS! KEEP GEAR OUT OF LIVING QUARTERS!
HCN CO Part II Example of Overall Toxic Reading Why Is it Important? LEL 8.0 OXYGEN 19.60 HCN 3.80 H 2 S 11.0 CO 645 Documentation of every event is extremely important for future evidentiary purposes and health- related concerns. This should be downloaded and attached to the Fire Report.
Special Thanks Special Thanks… St. Johns Fire Rescue Hazardous Materials team St. Augustine Florida Retired Jacksonville Fire Captain Rick Rochford Administration of First Coast Technical College St. Augustine, Florida Instructors of First Coast Technical College St. Augustine, Florida Draeger technical assistance team