Toxin

Phosphine Toxicity

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Phosphine Toxicity, Phosphine Gas, Phosphine

  • Background
  1. Phosphine (PH3) is released when metal phosphides such as aluminum come into contact with water
  2. Phosphine is used to manufacture semiconductors (Phosphorus introduced into silicon crystals)
  3. Other uses include fumigation, polymer synthesis, synthesis of flame retardants
  4. Also found in grain storage
  5. Solid phosphides may also release Phosphine Gas
  6. Phosphine is shipped as a liquefied and compressed gas
  • Mechanism
  • Toxicity
  1. Phosphine exposure may result in life-threatening toxicity
  2. Phosphine Toxicity directly affects alveolar capillary membranes
  3. Phosphines inhibit multiple enzymes that affect cell membranes
    1. Lipid peroxidation
    2. Protein denaturation
  4. Toxic dose
    1. Oral Lethal Doses
      1. Aluminum Phosphide: 500 mg
      2. Zinc Phosphoide: 4 grams
    2. Inhaled Gas toxicity
      1. Dangerous toxicity: 50 ppm
      2. Lethal exposure: 400 o 600 ppm (at <30 min of exposure)
  • Symptoms
  1. Exposure occurs with inhalation, ingestion or transdermal contact
    1. Symptoms below follow inhalation and ingestion exposure
  2. Inhalation is primary exposure
    1. Phosphine Gas smells like Garlic or decaying fish (may be odorless)
    2. Odor is not sufficient warning to prevent Inhalation Injury
  3. Gastrointestinal
    1. Nausea or Vomiting
    2. Diarrhea
  4. Respiratory
    1. Airway Irritation
    2. Chest Tightness
    3. Shortness of Breath
    4. Respiratory distress
  5. Neurologic
    1. Headache
    2. Ataxia
    3. Numbness or Paresthesias
    4. Tremor
    5. Muscle Weakness
    6. Coma (severe exposure)
    7. Seizures (severe exposure)
  6. Cardiovascular (severe exposure)
    1. Hypotension or shock
    2. Dysrhythmias
    3. Congestive Heart Failure
    4. End organ injury (liver, Kidney)
  • Labs
  1. No clinically relevant test for Phosphine available
  2. Arterial Blood Gas or Venous Blood Gas
    1. Metabolic Acidosis
    2. Respiratory Alkalosis
  • Diagnostics
  1. Electrocardiogram
    1. Evaluate for Dysfunction
  2. Echocardiogram
    1. Evaluate for Left Ventricular Failure, dilitation or hypokinesis
  • Imaging
  1. Chest XRay
    1. May demonstrate infiltrates
  • Management
  1. Decontamination
    1. See Decontamination
    2. Immediately remove from exposure
    3. Give charcoal 1 g/kg for ingestions
  2. Supportive care
    1. Advanced Airway as needed for acutre lung injury
    2. Intravenous Fluids and Vasopressors as needed for Hypotension
  3. Specific Management (experimental)
    1. N-Acetylcysteine
    2. Gastric Lavage
      1. Perform with Potassium permanganate (1:10,000) or Sodium Bicarbonate
  4. Disposition
    1. Observe for at least 24 hours for symptomatic inhalations or ingestions
    2. Observe for several hours if asymptomatic
  • Resources
  1. Phosphine Toxicity (CDC)
    1. https://www.cdc.gov/niosh/ershdb/emergencyresponsecard_29750035.html#:~:text=Inhaling%20phosphine%20causes%20respiratory%20irritation,adverse%20effects%20on%20the%20eyes.
  2. Metal Phosphides (EMDocs)
    1. http://www.emdocs.net/toxcard-metal-phosphides/
  • References
  1. Koch (2016) Crit Dec Emerg Med
  2. Sciuto (2016) Ann N Y Acad Sci 1374(1):41-51 +PMID: 27219283 [PubMed]
    1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4975009/