Toxin

Boric Acid Poisoning

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Boric Acid Poisoning, Boric Acid, Othorboric Acid, Boric Acid Toxicity, Borate, Borax

  • Background
  1. Boric Acid is a boron compound
    1. Available as a a fine white powder and in up to 5% solutions
  2. Boric Acid and related Borates have been used in various commerical products
    1. Insecticide (cockroaches, ants)
    2. Topical disinfectant
    3. Mouthwash and toothpaste
    4. Antimicrobial in Vulvovaginal Candidiasis
    5. Food preservative
  3. Borates are also used in industrial products
    1. Glazes and enamels
    2. Glass fibers
  • Mechanism
  • Toxicity
  1. Poisoning is typically by ingestion, but may also be absorbed via abraded skin
  2. Mitochondrial injury by boron hydroxyl complexes
  • Pharmacokinetics
  1. Ingestion <100 mg is typically asymptomatic
  2. Severe symptoms at >50 mg/kg
  3. Lethal dose: 15-20 g (2-3 g for infant)
  4. Renal Excretion
  5. Half-Life: 10-20 hours
  6. Volume of Distribution: 0.17 to 0.5 L/kg
  1. General
    1. Hyperthermia
  2. Cardiovascular Effects
    1. Hypotension
  3. Neurologic Effects
    1. Headache
    2. Lethargy to Coma
    3. Lightheadedness
    4. Irritabilty
    5. Seizure
  4. Gastrointestinal Effects
    1. Nausea
    2. Vomiting (blue-green appearance)
    3. Diarrhea (blue-green appearance)
    4. Abdominal Pain
    5. Mucositis
  5. Dermatologic Effects
    1. Diffuse skin erythema over face, axilla, inguinal region (red-orange coloration similar to boiled lobster)
    2. Rash progresses to Desquamation
  6. Renal Effects
    1. Acute Kidney Injury with Anuria (due to Acute Tubular Necrosis)
  • Labs
  1. Obtain full toxicologic workup
    1. See Unknown Ingestion
  2. Comprehensive Metabolic Panel
    1. Liver Function Test abnormalities (Transaminitis)
    2. Metabolic Acidosis with Anion Gap
    3. Osmolar Gap
  3. Boric Acid Levels
    1. Measured in urine and whole blood
    2. Borate levels poorly correlate with toxicity levels
  • Management
  1. See Unknown Ingestion
  2. Decontamination
    1. Remove contaminated clothing and wash skin with soap and water (topical exposure)
    2. Consider small bore nasogastric lavage (if recent large ingestion within last hour)
    3. Poor absorption by Activated Charcoal
  3. ABC Management
  4. Intravenous Fluid
    1. Promotes more rapid excretion
  5. Vasopressors (e.g. Norepinephrine) indicated in Hypotension refractory to Intravenous Fluids
  6. Hemodialysis Indications
    1. Severe Toxicity
    2. Acute Kidney Injury with Anuria
  7. Upper Endoscopy Indications
    1. Large ingestion with persistent gastrointestinal symptoms
  8. Medical admission indications
    1. Symptomatic patients (more than mild gastrointestinal symptoms)
    2. Neurologic findings
    3. Acute Kidney Injury
  • References
  1. Carroll and Yakey (2025) Crit Dec Emerg Med 39(6): 46
  2. Tomaszewski (2021) Crit Dec Emerg Med 35(2): 28
  3. Leikin (1995) Poisoning and Toxicology, Lexicomp, p. 870-1