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Hydrogen Cyanide. And the effects it has on the human body. Purpose. To understand the dangers of Hydrogen Cyanide and the possibilities of exposure for the personnel of the Helena Fire Dept. Objectives. Understand the unseen risks that are present in smoke.
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Hydrogen Cyanide And the effects it has on the human body
Purpose To understand the dangers of Hydrogen Cyanide and the possibilities of exposure for the personnel of the Helena Fire Dept.
Objectives • Understand the unseen risks that are present in smoke. • Learn about the more prevalent byproducts of combustion involved in a structure fire - specifically hydrogen cyanide. • Understand the effects of fire gases on the human body.
Objectives cont.. • Become informed of possible monitoring and treatment techniques that have been developed or tested. • Learn about what to do in the event of a possible exposure to a toxic byproduct.
Between 1997 and 2006, there were 30,564 fire deaths and 151,575 injuries attributable to fire. Only 1% of those represent burn injuries. The leading cause of fire death: SMOKE Inhalation.
Smoke defined Smoke: the gaseous product of burning materials especially of organic origin made visible by the presence of small particles of carbon. - Webster’s Dictionary
Anatomy of Fire Smoke The make-up of smoke can differ from fire to fire due to a number of different things • Although smoke from the majority of structure fires is mainly composed of particulate matters and heated gases. • Up to 80% of U.S fire related injuries and death are attributed to smoke inhalation.
Make-up cont.. • Irritants, asphyxiates, and toxins are a few of the very harmful agents found in smoke. • The major element of smoke that will be discussed today will be Asphyxiates. • Carbon Monoxide and Hydrogen Cyanide are also two of the most deadly gases present in a structure fire.
Asphyxiates • Asphyxiates are defined as an agent that causes death or injury by inhibiting the body from breathing normally • This can occur either at the cellular level, by not allowing oxygen to bind with red blood cells. • They can also cause a mechanical reaction such as swelling/edema of the airway.
Carbon Monoxide • Carbon monoxide (CO) is the most widely known gas that is produced from combustion. • CO is produced by the incomplete combustion of carbon materials and is both colorless and odorless.
CO cont.. • Carbon Monoxide is an asphyxiate that exerts its toxic effects by binding to the hemoglobin of the blood. • When CO is taken into the body, it will readily attach itself to the red blood cells. • CO is around 200-250 times more effective in binding to red blood cells than oxygen.
CO cont… • Carbon Monoxide becomes fatal by creating systemic hypoxia in all of the major organs of the body by not allowing oxygen to on load or off load from the red blood cells. • Exposure to low concentrations of CO (1-70 PPM) have been proven to be relatively benign.
CO cont… • People who have been exposed to more than 70 PPM will start to manifest symptoms. • Exposures of 150-200 PPM that are sustained will result in disorientation, unconsciousness and/or death.
Hydrogen Cyanide Hydrogen Cyanide (HC) is now becoming one of the more studied byproducts of combustion. Although CO is the usual focus, HC in fire smoke may be a significant factor in as many as 4000 fire related deaths and 20,000 injuries each year. HC is produced by the incomplete combustion of nitrogen containing substances.
Hydrogen Cyanide cont… These common materials such as – nylon, wool, polyurethane, silk, cotton, paper and PVC, as well as fiberglass insulation are used in all types of construction of structures and vehicles.
Hydrogen Cyanide cont.. Hydrogen Cyanide is a product of combustion under burning conditions where there is high temperature and low oxygen- The common house fire….. Each year there are 20,800 residential structure fires that are attributed to mattresses, pillows and bedding materials. • All of which burn two to three times hotter and faster than conventional materials.
Hydrogen Cyanide cont.. This in turn with the higher temperatures causes fires to reach flashover faster. Flashover-the high temp low oxygen condition that promotes the release of hydrogen cyanide.
Hydrogen Cyanide Cyanide is classified as a histo-toxin. All major organs that rely on oxygen are severely affected by cyanide poisoning. Early signs of small concentrations of cyanide poisoning could be mistaken for CO poisoning. The half life of HC is approximately one hour in blood.
Hydrogen Cyanide cont… These small exposures mimic CO by Hypoxia related symptoms- headaches, nausea, light headedness, anxiety and loss of judgment Exposures to large concentrations of cyanide manifest into cardiac arrhythmias (which can be delayed up to 2-3 weeks post fire exposure), stupor, coma or seizure that culminate into respiratory depression and death- The time of exposure to incapacitation and death is usually minutes.
Hydrogen Cyanide Cont… • The primary concerns regarding HC are its abilities to cause fatal health concerns and the inability or unavailability of assessing the problem. • Niosh has recognized that electrocardiogram changes can be observed two to three weeks after a fire related cyanide exposure.
Hydrogen Cyanide • This information alone raises many grave concerns as hundreds of firefighters succumb to heart attacks at fire scenes each year.
Hydrogen Cyanide cont… What is considered a lethal dose?
Threshold of odor Maximum safe exposure Slight symptoms (headache) Tolerated for ½ - 1 hour Fatal -1hour Fatal in ½ - 1 hour Fatal in 10 min Immediately fatal Hydrogen Cyanide cont… • 0.2-5.0 PPM • 10 PPM • 18-36 PPM • 45-54 PPM • 100 PPM • 110-135 PPM • 180 PPM • 280 PPM
Hydrogen Cyanide Cont… • TWA HCN- 4.7 PPM CO- 35 PPM • IDLH HCN- 50 PPM CO- 1200 PPM
Hydrogen Cyanide and Carbon Monoxide together Hydrogen Cyanide has been linked to increases in fire related deaths due to the fact of HC being an escape inhibitor. HC will also cause impairment of a victim so that they will not be able to think rationally or to be able to escape the fire. Low concentrations of HC have been shown to cause unconsciousness in fire victims.
HC and CO cont.. The theory of both of the gases working together is that HC will make escape for the victim very difficult. HC will also in turn make the victim lose consciousness more rapidly. Studies have shown that the person will then take in more of the toxic gases, such as CO, due to increased respirations from CO and the fact that they are unconscious.
Recognizing Acute Cyanide Poisoning Can you identify the possible victims in this picture?
Recognizing Acute Cyanide Poisoning Currently there is no diagnostic test to confirm cyanide poisoning in a rapid manner Even laboratory blood work performed at the hospital setting will not reveal cyanide poisoning in a timely manner Therefore cyanide poisoning should be suspected in any person exposed to smoke in a confined space- i.e. (A room and contents fire)
Rapid Breathing Dizziness Weakness Nausea/Vomiting Eye Irritation Pink or red skin color Rapid heart rate Perspiration Loss of consciousness Respiratory arrest Cardiac Arrest Coma Seizures Signs and Symptoms of Cyanide Poisoning
Pre-Hospital Treatment of Cyanide Poisoning • Basic life support of the victim includes removing the person from the source of exposure • Restoring or maintaining an open airway • Administering 100% supplemental oxygen via NRB or bag valve mask • Providing cardiopulmonary support and support of vital signs
Advanced Life Support • Aggressive advanced airway support such as intubation may be necessary • When necessary the administration of medications for seizures and cardiac arrest • If available the administration of a cyanide antidote kit
Cyanide Antidotes Currently there is only one FDA approved Pre-Hospital antidote kit available in the United States In 2006 the FDA approved Cyanokit for use in combating cyanide poisoning The antidote kit that is for sale includes the drug Hydroxocobalamin as well as intravenous tubing
Antidotes cont.. The drug hydroxocoblamin is a precursor to vitamin B-12, a relatively benign substance with minimal side effects The mechanism of action binds hydroxocoblamin to cyanide which then forms vitamin B-12, a non-toxic compound excreted in the urine Cyanokit can be administered to a pt suspected of cyanide poisoning without fear of any adverse reactions
Antidote cont… • The use of Cyanokit has been routinely used with documented success in Paris France • There the Paris Fire Brigade has routinely given Cyanokit to suspected cyanide poisoned victims with great success • From 1998-2002, 81 victims were given the antidote.
Antidote cont.. • Another study performed by DEY LABS, the company that produces Cyanokit, stated that Cyanokit had a 73% success rate when administered to 69 patients. • Subjects were over 15 years of age, presented with soot in the mouth and expectoration, and had altered neurological states.
Antidote cont.. Of the 69 patients given Cyanokit, 50 survived
Antidote cont… Cyanokit also had a 71% success rate with patients who either accidently or purposefully ingested/inhaled cyanide as well
Antidote cont… The Taylor kit, also referred to as the Lilly kit or the Pasadena Kit has been used in the hospital setting for many years. Although useful it has many adverse side effects that limit the effectiveness on smoke inhalation pts
Antidote cont… Other antidotes that have been in use outside of the United States for several years include • Dicobalt Ededate • 4-dimethylaminophenol (DMAP)
Detecting Hydrogen Cyanide Although HC is one of the most deadly fire gases produced in a structure fire, most fire departments do not monitor for it during an incident CO is one of the only gases that is monitored during the mop-up or salvage and overhaul stage of the fire
