6 Smoke Exposures It’s pretty simple - How Much? How Long?
7 Oxides of Nitrogen - NOx Deep lung irritant – may produce pulmonary edema A by-product of high-temperature combustion, NOX is produced when Oxygen and Nitrogen combine OSHA PEL: 5 ppm IDLH : 20 ppm Target Organs: CVS, Respiratory system
8 Oxides of Nitrogen - NOx - Strong irritants, particularly to mucous membranes. - When inhaled will damage tissues in the respiratory tract - Threshold limit value: 5ppm -Least amount causing immediate irritation to the throat: 62 ppm -Dangerous for short exposure: 117 to 154 ppm -Rapidly fatal for short exposure: 240 to 775 ppm
Oxides of Nitrogen - NOx Severe cases of non- cardiogenic pulmonary edema: up to 2 liters of fluid in the lungs. Onset can be delayed up to 6 hours
10 Formaldehyde Water soluble Heavier than air Flammable Gas at room temp Probable human carcinogen Sources: resins, plastics, preservatives, drying agent, tobacco smoke
11 Formaldehyde Acute health effects: Inflammation of lungs and respiratory tract, pulmonary edema. 2-3 ppm: nasal irritation 20-30 ppm: Breathing is difficult (IDLH) 50-100 ppm: Serious injury; pulmonary edema
12 Vinyl Chloride Key component of plastics industry (PVC) Known carcinogen Affects liver, CNS, lymphatic system Toxic by inhalation and absorption OSHA PEL: 1ppm
13 Poly Vinyl Chloride Wire insulation, electrical conduit, plumbing pipe, molded plastic furniture, etc. Decomposition temperature: 450-500 degrees F
14 Do you think it’s a reasonable proposition to inhale microscopic shards of glass coated with phenol- formaldehyde? Fiberglass – SMF’s
15 Particulates - Soot - Byproduct of incomplete combustion - Known human carcinogen; lung cancer - PAH’s – polycyclic aromatic hydrocarbons OSHA PEL: 0.2 mg/m3 Toxic by inhalation, ingestion
17 Cyanide produced by combustion of both synthetic and natural substances Most common source of acute cyanide poisoning in the US Contributes significantly to smoke inhalation injury and death Fire Smoke A Source of Cyanide
18 Natural substances Wool Silk Cotton Paper Synthetic substances Plastics Other polymers Plastics Sources of Cyanide in Fire Smoke
19 Cyanide Compounds 10 ppm: Threshold limit value 20-40 ppm: Slight Symptoms after several hours of exposure 50-60 ppm: Maximum amount that can be inhaled for1 hour without serious disturbance 120-150 ppm: Dangerous in 30 minutes to 1 hour 3000 ppm: Rapidly fatal
20 Cyanide Compounds Half-life of cyanide in the body is about 1 hour Cannot be detected by smell in 40%-60% of the population Deficit is greater in men by 3:1 35 times more toxic than CO
HCN – An Invisible Threat... Absence of a rapidly returnable diagnostic test for cyanide poisoning reinforces the perception of carbon monoxide as the primary contributor to smoke inhalation injuries and deaths. Eckstein M, Maniscalco PM. Prehosp Disast Med. 2005;21:s49-s55. Watson WA, et al. 2004 Annual Report of the American Association of Poison Control Centers Toxic Exposure Surveillance System.
... or Just Ignored? Substrates for hydrogen cyanide frequently found in modern buildings (natural and synthetic substances containing carbon and nitrogen, such as wool, silk, and some plastics) Release of hydrogen cyanide highly probable and to be expected in enclosed-space fires Cyanide can act independently from carbon monoxide Eckstein M, Maniscalco PM. Prehosp Disast Med. 2005;21:s49-s55. Alaire Y. Critical Reviews in Toxicology. 2002;32;259-289. Flomenbaum NE, et al. Goldfrank’s Toxicologic Emergencies. McGraw-Hill. 2006.
Toxicity of Fire Smoke: Conclusions Cyanide is likely to be present in appreciable amounts in fire victims’ blood Cyanide is a common product of combustion – which is treatable if diagnosed. Frequent co-exposure to carbon monoxide and cyanide occurs Although carbon monoxide is likely a major toxicant in fires, cyanide can sometimes be the principal cause of death Numerous deadly toxicants exist in toxic fire smoke, which if exposed acutely or chronically (NOT ON AIR) – can cause disease or death. Alaire Y. Critical Reviews in Toxicology. 2002;32:259-289.