5.1 Given an inhalation exposure, identify which substance is responsible.
5.2 Given an exposure with a cluster of patients, identify which chemical weapon of mass destruction is responsible.
5.3 Identify the toxicity and symptoms of chemical exposures.
5.4 Gases
5.4 Identify the toxicity and symptoms from exposure to gases.
a. Gas and aqueous forms found in fertilizers, refrigerants, cleaning solutions, explosives
i. Household cleaners concentration 5% to 10%
ii. Commercial cleaners concentration 25% to 30%
b. Alkaline. Corrosive on contact with moist tissues
c. Exposure may be dermal, ophthalmic, respiratory, or GI
i. Ammonia (Dermal)
ii. Ammonia (Ophthalmic)
iii. Ammonia (Respiratory)
iv. Ammonia (GI)
a. Ammonia combined with chlorine or hypochlorite solutions produce chloramine gas
b. Irritant.
c. Exposure is generally respiratory
d. S/S: Similar to chlorine gas exposure
i. Chloramine fumes cause pneumonitis
ii. Less water soluble than chlorine. Symptoms may be more delayed
e. Treatment
i. Remove from source
ii. High flow O2
a. Found in chemical manufacturing, bleaching, swimming pools, and disinfectants
i. Hypochlorite is aqueous solution of chlorine with water
b. Acidic. Irritant
i. Heavier than air
ii. Irritating odor; yellow-green gas
c. Exposure route dermal, respiratory, GI
d. S/S: Oxidative and corrosive when contacting moist tissues
Chlorine (Dermal)
Chlorine (Respiratory)
Chlorine (GI)
Chlorine Evaluation:
i. Watch for hypochloremia & acidosis
ii. ABG for hypoxia
iii. CXR for pneumonitis and pulmonary edema
a. Mild CNS depressants/asphyxiants.
i. Well absorbed by inhalation or ingestion.
ii. Usually rapidly excreted in the breath within 15-60 min
b. Exposure route usually dermal or respiratory
c. Freon S/S
i. Mild irritant
ii. Direct freezing of the skin
iii. Hepatotoxic with large exposure
iv. May potentiate cardiac arrhythmias by sensitizing the myocardium
a. Source is often inhaled zinc oxide; can have symptoms from welding, melting, and flame
cutting of galvanized metal
b. S/S
i. Fever
ii. Malaise
iii. Myalgia
iv. Headache
v. *Should not have hypoxia or pulmonary infiltrates
1. If present, suspect chemical pneumonitis from another source
c. Treatment
i. S/S should self-resolve
ii. No decontamination is required. By time of s/s onset, exposure is past
a. Byproduct of decaying organic material. Pools of sewage or sludge, liquid manure. Industrial processes often found in petroleum refineries, tanneries, mines, pulp-making factories, sulfur hot springs, carbon disulfide production, commercial fishing holds, hot asphalt fumes.
b. Knock-down gas
i. “pit gas” – heavier than air
ii. Known for rotten egg smell
iii. cellular asphyxia (similar to cyanide)
c. Exposure route generally respiratory
d. Hydrogen Sulfide S/S
i. Chemical irritant at low doses
1. Upper airway, eye, skin, irritation
2. Chemical pneumonitis, non-cardiogenic pulmonary edema
ii. Acute systemic effects
1. n/v, headache, dizziness, confusion, sz, coma,
iii. Massive exposure
1. Immediate cardiovascular collapse, respiratory arrest and death
e. Hydrogen Sulfide Treatment
i. Remove from source
ii. Possible use of nitrites (sodium nitrite and amyl nitrite)
1. To promote methemoglobin (binds a component of the poisonous gas)
2. May cause hypotension and impaired O2 delivery
iii. Possible use of hydroxycobalamin
1. Not proven
iv. Possible use of hyperbaric oxygen
a. Found in manufacture of dyes, resins, plastics, and pesticides; used as a war gas
b. Irritant
i. Heavier than air
ii. Smell of freshly mown hay
iii. Poorly water soluble
Enters lower airways
Does not cause immediate irritation
c. Phosgene S/S
i. Initial mild cough and minimal mucous membrane irritation
ii. Delayed dyspnea and hypoxemia (30 min-8 hrs)
iii. Resultant noncardiogenic pulmonary edema (up to 24 hrs)
d. Phosgene Treatment
i. Remove from source
ii. Remove clothes and decon
iii. Maintain airway
iv. Low threshold for intubation. Use large ETT (frequent suction)
v. monitor asymptomatic patient for 24 hrs after exposure
vi. No antidote