Case Definition: Arsenic (Inorganic)

Clinical description

Acute ingestion of toxic amounts of inorganic arsenic typically causes severe gastrointestinal signs and symptoms (e.g., vomiting, abdominal pain, and diarrhea). These signs and symptoms might lead rapidly to dehydration and shock. Different clinical manifestations might follow, including dysrhythmias (prolonged QT, T-wave changes), altered mental status, and multisystem organ failure that ultimately might result in death (1-4).

Laboratory criteria for diagnosis

  • Biologic: A case in which elevated urinary arsenic levels (>50 µg/L for a spot or >50 µg total for a 24-hour urine) exist, as determined by commercial laboratory tests. Speciation is required in all cases where total urine arsenic is elevated to differentiate the amount of organic and inorganic arsenic.


  • Environmental: Detection of arsenic in environmental samples above expected background levels.

Case classification

  • Suspected: A case in which a potentially exposed person is being evaluated by health-care workers or public health officials for poisoning by a particular chemical agent, but no specific credible threat exists.
  • Probable: A clinically compatible case in which a high index of suspicion (credible threat or patient history regarding location and time) exists for arsenic exposure, or an epidemiologic link exists between this case and a laboratory-confirmed case.
  • Confirmed: A clinically compatible case in which laboratory tests have confirmed exposure.

The case can be confirmed if laboratory testing was not performed because either a predominant amount of clinical and nonspecific laboratory evidence of a particular chemical was present or the etiology of the agent is known with 100% certainty.

Additional resources

  1. Munday SW, Ford MD. Chapter 88: Arsenic. In: Nelson LS, Lewin NA, Howland MA, Hoffman RS, Goldfrank LR, Flomenbaum NE, eds. Goldfrank’s Toxicologic Emergencies. 9th ed. New York, NY: McGraw-Hill; 2011:1214-28.
  2. Bolliger CT, van Zijl P, Louw JA. Multiple organ failure with the adult respiratory distress syndrome in homicidal arsenic poisoning. Respiration 1992;59:57–61.
  3. Civantos DP, Lopez RA, Aguado-Borruey JM, Narvaez JA. Fulminant malignant arrhythmia and multiorgan failure in acute arsenic poisoning. Chest 1995;108:1774–5.
  4. Heyman A, Pfeiffer JB Jr, Willett RW, Taylor HM. Peripheral neuropathy caused by arsenical intoxication. A study of 41 cases with observations on the effects of BAL (2,3 dimercapto-propanol). N Engl J Med 1956;254:401-9.
  5. American Conference of Government Industrial Hygienists (ACGIH). Documentation of biological exposure indices. 7th edition. Cincinnati (OH): ACGIH Worldwide; 2001.
  6. NIOSH. NIOSH manual of analytical methods [online]. 2003. [cited 2013 Apr 5]. Available from URL:
  7. OSHA. Sampling and analytical methods [online]. 2010. [cited 2013 Apr 5]. Available from URL: icon.
  8. FDA. Food: Laboratory methods [online]. 2013. [cited 2013 Apr 5]. Available from URL: icon.
  9. EPA. Selected analytical methods: chemical methods query [online]. 2013. [cited 2013 Apr 5]. Available from URL: icon.
Page last reviewed: April 4, 2018