Ammonia toxicity

Background

• Liquid form common in cleaning products
• Ammonia gas used as chemical weapon
• Injury due to inhalation, skin/eye contact, and/or ingestion
• Extent of injury contingent upon concentration and duration of exposure
  • Even fairly low airborne concentrations (50 ppm) of ammonia produce rapid onset of eye, nose, and throat irritation; coughing; and narrowing of the bronchi.

Clinical Features

Routes of Exposure

• Inhalation
  • Nasopharyngeal and tracheal chemical burns, upper airway obstruction
  • Bronchiolar/alveolar edema and narrowing
  • Laryngospasm (can occur immediately upon exposure)
  • Respiratory distress/failure, hypoxia
  • Cough
• Skin contact
  • Dilute (e.g. household cleaners) rarely burn but may be irritating
  • Corrosive injury if contact with concentrated (e.g. industrial cleaners >25%)
    • Skin chemical burns, blistering, pain, necrosis, particularly on moist skin areas
    • Contact with compressed liquid ammonia (stored at -28 °F) can cause frostbite injury and deep ulcerating burns
• Eye contact
  • Greater tendency to penetrate/damage eye than other alkali
  • Temporary or permanent vision loss if contact with high concentrations of the gas or with concentrated ammonium hydroxide, due to swelling/sloughing of eye surface cells
    • Extent of damage may not be apparent for up to a week
• Ingestion
  • Corrosive damage/chemical burns to oropharynx, esophagus, stomach
    • --> Nausea/vomiting, chest pain, abdominal pain, drooling

Differential Diagnosis

Caustic Burns

• Caustic ingestion
• Caustic eye exposure (Caustic keratoconjunctivitis)
• Caustic dermal burn
• Airbag-related burns
• Hydrofluoric acid
• Tar burn
• Cement burn

Chemical weapons

• Blister chemical agents (Vesicants)
  • Lewisite (L)
  • Sulfur mustard (H)
  • Phosgene oxime (CX)
• Pulmonary chemical agents (Choking agents)
  • Ammonia toxicity
  • Methyl isocyanate
  • Methyl bromide
  • Hydrochloric acid
  • Chlorine gas
  • Phosgene
• Incendiary agents
  • Agent orange
  • White phosphorus
• Cyanide chemical weapon agents (Blood agents)
  • Prussic acid (AKA hydrogen cyanide, hydrocyanic acid, or formonitrile)
• Nerve Agents (organophosphates)
  • Acetylcholinesterase inhibitors
  • Household and commercial pesticides (diazinon and parathion)
  • G-series (sarin, tabun, soman)
  • V-series (VX)
• Lacrimating or riot-control agents
  • Pepper spray
  • Chloroacetophenone
  • CS

Evaluation

• Decontaminate
• Evaluate for extent of injury, co-intoxicants

Management

• Diuretics and corticosteroids not shown to be effective
• Inhaled beta agonists e.g. albuterol for bronchoconstriction
• See caustic ingestion
• See caustic burns

Disposition

• Dependant on clinical severity

See Also

• Pulmonary chemical agents