Arsine (AsH3)

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Arsine (AsH3)
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Arsine - Overview

• Highly poisonous, colorless, nonirritating,
  flammable gas
• Mild garlic odor at 0.5 ppm
• 2.5 times heavier than air
• Soluble in water
• Used commercially
• organic synthesis
• processing of electronic components

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Arsine - Toxicity

• Most acutely toxic form of arsenic
• Preferentially binds to hemoglobin
• Oxidizes to arsenic-dihydride intermediate and
  elemental arsenic, both hemolytic agents
• Direct and severe effect on the liver, spleen,
  kidneys, lungs, and other organs

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Arsine - Toxicity

• Major route of toxicity in inhalation
• Children may be more vulnerable
• Acute poisoning accidental
• OSHA standard 0.05 ppm (0.2mg/m3)
• NIOSH standard 0.002 mg/m3
• Mean lethal dose is unkown, but 250 ppm is
  instantly lethal

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Protective Equipment

• Chemical protective clothing not required
• Respiratory protection options
• Positive-pressure, self-contained apparatus
  (SCBA)
• Supplied-air respirator with full facepiece
• Gas mask with a chin-style, front or back mounted
  canister

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Detection

• Variety of arsine monitors and gas sensors
  available commercially
• Can detect arsine at levels as low as 0.05 ppm

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Decontamination

• For arsine gas only, additional decontamination
  is not required
• Remove victims immediately from exposure site to
  fresh air
• Exposure to solid arsenic salt may require
  further decontamination

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Signs and Symptoms

• Characteristic features
• Abdominal pain
• Bloody urine
• Jaundice

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Signs and Symptoms

• Initial Symptoms
• Headache, thirst, shivering, malaise, weakness,
  dizziness, dyspnea, abdominal and back pain,
  hepatomegaly, nausea and vomiting
• Development usually noted 2 to 24 hours post
  exposure
• Garlicky odor on the breath

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Signs and Symptoms

• EKG changes and dysrhythmias likely
• Severe exposure hypotension
• CNS disorders can develop days after severe
  exposure
• Peripheral nerve damage 1 to 2 weeks after
  exposure

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Signs and Symptoms

• Hematuria
• Light to dark red
• 4-6 hours after exposure
• Jaundice 12 to 48 hours later
• Hemolysis continues up to 4 days
• Unusual bronze skin discoloration

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Signs and Symptoms

• Hemoglobin destruction
• Clog kidneys
• Produce acute tubular destruction and renal
  failure
• Other toxic effects
• Lung, liver and heart damage
• Frostbite injury possible

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Laboratory

• Evident in peripheral smear
• Varying size/shape of red blood cells
• Red-cell fragments
• Heinz bodies
• Ghost cells
• Cell component affinity for basic dyes

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Laboratory

• Bone marrow unremarkable
• Coombs and Ham tests negative
• RBC fragility is normal

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Laboratory

• Urinalysis myoglobinuria
• Large amounts of protein and free hemoglobin
• Brown, red, orange, or greenish urine
• Elevated serum globulin, CPK and liver enzymes
• Prolonged prothrombin time

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Treatment

• Basic first aid for victims
• Prompt medical attention
• No specific antidote
• Supportive of respiratory, vascular and renal
  function
• Oxygen and fluids
• Bronchodilators
• Racemic epinephrine for children

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Treatment

• NIOSH treatment guidelines
• Blood exchange transfusion
• Administer dimercaprol BAL
• BAL standard dosing 3-5 mg/kg IM q4hr for 4
  doses
• May not be effective in acute toxic events

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Treatment

• Hemolysis
• Start urinary alkalinization
• Monitor serum electrolytes, Ca, BUN,
  creatinine, hemoglobin and hematocrit
• Start dialysis
• Consider BAL if suspicious of toxic arsenic
  levels

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Long-Term Medical Sequelae

• Anemia may persist several weeks
• Polyneuropathy and altered mental status reported
  1-6 months after poisoning
• Arsenic compounds are known human carcinogens
• Potential teratogenic agent

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Environmental Sequelae

• Environmental effects not reported
• Exposure to light
• Moist arsine decomposes quickly
• Deposits shiny black arsenic

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Summary

• Potential for terrorist use
• Lethal
• Can be dispersed as gas

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Summary

• Most acutely toxic form of arsenic
• Preferentially binds to hemoglobin
• Oxidizes to arsenic-dihydride intermediate and
  elemental arsenic
• Characteristic Features
• Abdominal pain, bloody urine, jaundice w/ severe
  hemolytic anemia

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Summary

• Hematuria
• Light to dark red w/in 4-6 hours
• Jaundice w/in 12-48 hours
• Acute tubular destruction and renal failure
• No antidote
• Supportive treatment
• Dialysis