HYDROGEN CYANIDE THE OTHER SILENT KILLER COURSE OBJECTIVES
HYDROGEN CYANIDE THE OTHER SILENT KILLER
COURSE OBJECTIVES The goal of this program is to provide the learner with a thorough understanding of Hydrogen Cyanide including the following: Awareness and Recognition Prevention Protection Detection Diagnosis & Treatment
COURSE CONTENTS Chemical Properties HCN and CO – “The Toxic Twins” Literature Review Case Studies & Research Columbia Fire Department Fort Worth, Texas Equipment Response Protocol Hands-on Training
Would you work here without SCBA? CHLORINE GAS
…so then why do it here? Ammonia Dioxin Benzopyrine Formaldehyde Chloromethane Benzene Phosgene Methane Ethylene Oxides of Nitrogen Carbonyl Fluoride Carbon Dioxide Carbon Monoxide Furfural Sulfur Dioxide PCB’s Bromomethane Hydrogen Sulfide Alcohols Hydrogen Cyanide Acetic Acid Acrolein
Chemical Properties Physical Properties and Health Effects of Hydrogen Cyanide
Properties of HCN Hydrogen cyanide is a chemical compound with chemical formula HCN. It is a colourless, extremely poisonous liquid that boils slightly above room temperature at 26 °C (79 °F). HCN has a faint, bitter, burnt almond-like odour that only some people are able to detect owing to a genetic trait. The volatile compound has been used as inhalation rodenticide and human poison. Cyanide ions interfere with iron -containing respiratory enzymes.
Properties of HCN – Exposure Limits IDLH – 50 ppm (Carbon Monoxide is 1200 ppm) NIOSH REL – 5 ppm (Carbon Monoxide is 25 ppm) OSHA PEL – 10 ppm EPA AEGL 3 (Life threatening effects or death) 10 minutes – 27 ppm 30 minutes – 21 ppm EPA AEGL 2 (Long lasting effects or impairment) 10 minutes – 17 ppm
Properties of HCN Extremely poisonous, Extremely flammable LEL 5. 6% - UEL 40% Vapour Density - 0. 93 (slightly lighter than air) Vapour Pressure – 630 mm. Hg Molecular Weight = 27. 03 Ionization Potential = 13. 6 e. V Odour Threshold = 0. 58 ppm* *Burnt almond odour. Firefighters will not be able to smell HCN amongst burning materials. 40% of the population cannot smell HCN.
Properties of HCN NIOSH – Physical Dangers Hazardous concentrations may develop quickly in an enclosed environment or poorly ventilated areas Mixes well with air, explosive mixtures are easily formed 24 times more toxic than Carbon Monoxide Magnifies the toxicity of HCN when combined with CO (“Toxic Twins”) http: //en. wikipedia. org/wiki/Hydrogen_cyanid
Health Effects – Signs & Symptoms MODERATE EXPOSURE Headache Confusion Anxiety Blurred vision Loss of judgment Increased respiratory rate SERIOUS EXPOSURE Dyspnea Cardiac dysrhthmia Seizures Coma Death
Health Effects Potential Symptoms: Asphyxia and death at high levels, preceded by seizures, coma with abolished deep reflexes and dilated pupils, paralysis, weakness, dizziness, numbness, tremor, loss of visual acuity, headaches, nausea, vomiting, loss of appetite, weight loss, increased rate and depth of respiration, or slow and gasping respiration, eye irritation, rash, chemical burns on skin, enlargement of the thyroid gland. [NIOSH]
Health Effects Long Term Effects/Repeated Exposures Respiratory problems Weakness Heart disease Heart attack Stroke Brain damage Thyroid cancer
Health Effects Workers exposed to concentrations of 412 ppm periodically over a period of 7 years showed an increase in symptoms of headache, weakness, irritation of throat, change in taste and smells, and nervous instability [ACGIH 1991] Workers exposed to low concentrations of Hydrogen Cyanide have developed enlarged thyroid glands [NLM 1995]
Health Effects – Signs & Symptoms “Exposure to smaller concentrations can initially cause respiratory activation (manifested by rapid breathing and tachycardia) in an attempt to compensate for lack of oxygen. Early manifestations include headache, anxiety, blurry vision, and loss of judgment. As cyanide accumulates further, signs and symptoms of poisoning reflect the effects of oxygen deprivation on the heart and brain. These include cardiac dysrhythmias, seizure, coma, and death. ” “The time between exposure and incapacitation or death is typically minutes, but varies depending on the concentration of cyanide and other toxicants. ” O’Brien, DJ, Walsh, DW, Cyanide and Smoke Inhalation, 2010
HCN – Reference Materials UN 1051, Class 6 (Subclass 3) ERG Guide #117 – “Gases – Toxic – Flammable (Extreme Hazard) (Initial Isolation Zone of 60 M for a small release) NIOSH Pocket Guide Page #168 NFPA 704 – Health 4, Flammability 4, Reactivity 2
Case Studies and Research Let’s look at some of the current studies and stats regarding HCN
Cyanide Poisoning of Providence RI Firefighters March 23 rd 2006 Firefighter Kenneth Baker was confirmed to have cyanide poisoning due to a fire call He suffered a heart attack and died at a structure fire later that same shift As a result, all FF’s who were at the first call were tested 8 of 27 firefighters tested had high levels of HCN in their systems CLICK HERE FOR PROVIDENCE REPORT - review pages 2 & 3 of the report
Thyroid Testing – During Physicals Largo (FL) Fire Rescue Ultra Sound 8 employees with thyroid nodules, 2 resulted in cancer and 1 yet to be determined 1 aneurysm 1 70% blocked carotid arteries Las Vegas Fire Department 8 thyroid cancers 3 brain cancers
Columbia Fire Department Study Eight month study monitoring CO and HCN at fire calls (approximately 40 structure fires) Found staggering results with extremely high HCN levels at calls Found no correlation between CO and HCN production Worst offenders for HCN production were: “Pot on a stove”/cooking fires (average small kitchen fire produces 75 ppm of HCN) Car fires Dumpster fires Overhaul operations
Fort Worth Texas Test Burns Conducted “open-air” burn study to capture HCN levels off of different materials Significant levels obtained in an “open-air” environment Highest levels were recorded at incipient stages of fire production and during smoldering periods This study confirmed what was being readily assumed about HCN levels in air during fires CLICK HERE FOR THE FORT WORTH STUDY
Prevention, Protection & Detection Let’s look at how we can protect ourselves from HCN exposure
Prevention and Protection Most important prevention tool is AWARENESS – we need to be educated on HCN Recognizing Signs & Symptoms of exposure PPE (use & cleaning) Monitoring for HCN Establishing action levels Reporting levels and exposures Decontamination procedures HCN Standard Operating Guideline (CLICK
Detection Sensit P 100 Single Gas HCN detector Located on secondary vehicles To be used at all fire related calls Can be used to monitor the atmosphere at incidents as well as readings off of PPE
Operational Implementation HCN air monitoring shall be conducted at all fire occurrences and will help determine: Scene perimeter and the locations of rehab, accountability, other agencies, etc. (extremely valuable tool for the ISO) The need for “on scene” gear decontamination and/or replacement (worst offenders for HCN retention are balaclavas and helmet ear flaps) The severity of smoke inhalation cases for firefighters and civilians (signs and symptoms) When we can operate off-air at an occurrence (action levels) LETS DISCUSS EACH OF THESE POINTS IN
Review HCN is more dangerous than Carbon Monoxide The IDLH of CO is 1200 ppm, while the IDLH of HCN is 50 ppm Low CO levels present a false security to the presence of HCN has a short half-life, this can make it difficult to fully diagnose the level of exposure Early detection is imperative to the safety of personnel HCN symptoms in lower level exposures are similar to heat related illness and CO poisoning
Review cont…. . HCN symptoms in severe or acute cases mirror that of a heart attack More firefighter and civilian deaths are being linked to HCN poisoning Poor firefighter PPE usage leads to increased exposure of HCN and CO Wear your SCBA at all fire calls PROTECT YOURSELF!
Additional Resources & Info AFTERMATH VIDEO - CLICK HERE TO WATCH Very informative video about HCN exposure, repsonse and treatment 37 minutes long “Smoke”, Dr. David Penney – CLICK HERE TO READ “Cyanide and Modern Fires”, EMD Serano Pharmaceuticals – CLICK HERE TO READ
Additional Resources & Info www. firesmoke. org Great resource for HCN and smoke related material Articles Research studies Etc. Login to access all the available information Username: joness@burlington. ca Password: firefighter
Final thought…. .
How many of us have been somewhere like this? 38 PPM of HCN! -Actual incident photo and monitoring results from Columbia FD Study
- Slides: 31