Phosphine (PH3)

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Phosphine (PH3)
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Phosphine - Overview

• Physical properties
• Colorless gas
• Heavier than air
• Odorless in pure form
• Garlic odor added commercially
• Low odor threshold of .15 ppm
• Highly explosive

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Phosphine - Overview

• Semiconductor industry
• Fumigant and polymerization initiator
• Metallic salts used as grain fumigants and
  rodenticides
• Useful to terrorists seeking to disable groups of
  people more so than killing them

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Phosphine - Toxicity

• Major route is inhalation
• No effect on the skin or eyes
• Liquefied or compressed gas may cause frostbite
• Gas at room temperature
• Metallic phosphides ingestion or prolonged dermal
  exposure may cause systemic toxicity

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Phosphine - Toxicity

• Children vulnerable
• Greater lung surface area to body weight ratio
• Increased minute ventilation per kg
• Short stature

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Phosphine - Toxicity

• OSHA
• 0.3 ppm averaged over 8-hour work shift
• NIOSH IDLH 50 ppm
• Level of 0.5 ppm
• Maximum airborne concentration
• Exposed up to 1 hour without experiencing or
  developing serious adverse health effects

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Protective Equipment

• Positive-pressure, SCBA advised
• Chemical-protective clothing not required
• Use rubber gloves and aprons

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Detection

• Odor cannot be trusted
• Variety of monitors and gas sensors are available
  commercially

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Decontamination

• Remove individuals from contaminated area
• Remove, double-bag clothing and personal
  belongings

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Decontamination

• Eye exposure
• Flush eyes with water
• Skin exposure
• Brush visible particles from skin and hair
• Flush with water
• Wash with soap and water

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Decontamination

• Avoid hypothermia in children elderly
• Secondary contamination
• Exposed only to phosphine gas do not pose risk
• Metallic phosphides on clothes, skin, or hair can
  off-gas after contact with water or moisture
• Vomitus containing phosphides can off-gas

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Signs and Symptoms

• Clinical Diagnosis
• Respiratory tract irritant
• Attacks cardiovascular, respiratory systems
• Peripheral vascular collapse, cardiac arrest and
  failure, and pulmonary edema

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Signs and Symptoms

• Enzyme, protein synthesis interference
• Cation disturbances alter transmembrane
  potentials, primarily in the mitochondria of
  heart and lung cells
• Clinical manifestations
• Hypotension, reduced cardiac output, tachycardia,
  irregular heart beat

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Signs and Symptoms

• Affects small peripheral vessels
• Decrease in systemic vascular resistance
• Severe hypotension
• Cardiac arrest and peripheral vascular collapse
  can occur
• Most deaths cardiovascular related

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Signs and Symptoms

• Respiratory toxicity
• Chest tightness, cough, shortness of breath
• Severe exposure
• Pulmonary edema, delayed onset of up to 72 hours
• Pulmonary edema and pneumonitis results from
  direct cytotoxicity to pulmonary cells

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Signs and Symptoms

• CNS depressant effects
• Headache, restlessness, dizziness, loss of
  feeling, impaired gait, trembling of the
  extremities during movement, and double vision
• Severe exposure
• Seizures and coma

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Signs and Symptoms

• GI symptoms
• First symptoms to occur
• Liver damage
• Evident 48 - 72 hours later
• Jaundice, hepatomegaly, elevated serum
  transaminases and bilirubin
• Centrilobular necrosis reported
• Hematuria, proteinuria, and acute kidney failure

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Signs and Symptoms

• Laboratory
• Blood gas analysis reveal respiratory and
  metabolic acidosis
• Abnormal cardiac isoenzymes, liver enzymes, and
  urine findings
• Significant hypomagnesemia or hypermagnesemia
• Massive focal myocardial damage

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Signs and Symptoms

• Chronic exposure at low concentrations
• Anemia
• Bronchitis
• Nausea and other GI disturbances
• Nasal and pharyngeal inflammation
• Weakness, dizziness, jaundice
• Other liver effects
• Increased bone density
• Visual, speech, and motor disturbances

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Signs and Symptoms

• Chronic exposure
• More serious for children
• Potential longer latency period

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Treatment

• Basic first aid for victims
• No specific treatment
• Care is primarily supportive
• Steroid efficacy not proven
• Hemodialysis for renal failure
• Exchange transfusion effectiveness questionable

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Treatment

• Follow ABCs
• Comatose, hypotensive, or seizing patients
• Supportive care with intravenous fluids, pressor
  agents, sodium bicarbonate, or anticonvulsants

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Treatment

• Adult victims
• Shock or severe hypotension
• 1,000 mL bolus of IV saline or lactated Ringers
  solution over one hour
• Follow with infusion at 150 to 200 mL/hour
• Systolic pressure over 90 mmHg
• Begin fluid infusion without the initial bolus

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Treatment

• Children
• 20 mL/kg bolus normal saline over 10 to 20
  minutes
• Follow with infusion at 2 to 3 mL/kg/hour
• Significant acidosis
• Sodium bicarbonate intravenously
• Additional therapy guided by arterial blood gas
  measurements

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Treatment

• Pulmonary support
• Supplement O2 for dyspnea or hypoxia
• Observe for at least 72 hours
• IPPB, PEEP mask or, intubation may delay or
  minimize pulmonary edema and reduce hypoxia

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Treatment

• Aerosolized bronchodilators acute bronchospasm
• Consider myocardial health when choosing
  bronchodilator
• Racemic epinephrine aerosol for children who
  develop stridor
• Dose 0.250.75 mL of 2.25 racemic epinephrine
  solution in water
• Repeated every 20 minutes

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Treatment

• Ingestions
• Remove quickly from GI tract
• DO NOT induce emesis
• Gastric lavage with potassium permanganate
  solution
• Oxidizes phosphine in stomach to form phosphate
• Follow lavage with activated charcoal slurry
• Mineral oil cathartic recommended

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Treatment

• Routine laboratory studies
• CBC, basic metabolic panel, renal function tests,
  liver-function tests and serial cardiac
  isoenzymes
• Diagnostic studies
• ECG, chest radiography, pulse oximetry, blood
  gases, and PFl3

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Long-Term Medical Sequelae

• Most survivors show no permanent disabilities
• Myocardial infarct or stroke are possible
• Subacute poisoning may cause reactive airways
  dysfunction syndrome months later
• EPA determined not classifiable (Group D)

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Environmental Sequelae

• Changed to less harmful chemicals
• less than one day in air
• Removed from air by contact with moist soil
• Disappears from soils of 50 or more water
  content in less than 5 weeks
• Majority is recoverable as orthophosphate

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Summary

• Terrorist use may cause disruption and fear
• Pulmonary irritant systemically affects
  cardiovascular respiratory systems
• Metallic phosphides produce systemic effects when
  ingested

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Summary

• Clinical manifestations
• Hypotension, pulmonary edema, reduced cardiac
  output, tachycardia, and irregular heart beat
• Cardiac arrest and peripheral vascular collapse
• No specific treatment
• Most survivors show no permanent disabilities