Sniff a poison challenge

aka Toxicology Conundrum 027

As you review a patient you notice an unusual scent about his person…welcome to the ‘Sniff a Poison‘ Challenge!

How this works

Below is a list of odo(u)rs. For each different odour try to identify the poison(s) or toxin(s) that can give rise to it – then click on the odour (in blue) to show/hide the answer. If there are multiple answers, the number of answers listed is shown in brackets.

…Start sniffing!

  • ammonia
  • (its good to get off to an easy start…)
Bitter almonds
  • cyanide
  • (40% of people are genetically incapable of smelling this)
Burnt rope (2)
  • marijuana
  • opium
Disinfectant (2)
  • phenol
  • creosote
Fruity (12!)
  • nitriles
  • isopropyl alcohol
  • ketoacidosis
  • lacquer
  • ethanol
  • isopropanol
  • chloroform
  • trichloroethane
  • paraldehyde
  • chloral hydrate
  • methylbromide
  • nitrites (amyl, butyl)
Garlic (7)
  • phosphorus
  • tellurium
  • inorganic arsenicals and arsine gas
  • organophosphates
  • selenium
  • thallium
  • dimethyl sulfoxide
Fish or raw liver (musty) (3)
  • zinc phosphide
  • aluminum phosphide
  • nickel carbonyl
  • phosgene
Mint (2)
  • methylsalicylate (Oil of Wintergreen)
  • menthol
Mothballs (3)
  • napthalene
  • camphor
  • p-dichlorobenzene
  • chloral hydrate
  • o-chlorobenzylidene malonitrile (CS or tear gas)
  • pine oil
Rotten eggs (5)
  • Hydrogen sulfide (olfactory fatigue occurs after about 15 minutes at the potentially toxic level of 50 ppm. This happens even faster at higher concentrations – so the victim is at least spared the stench of rotten eggs…)
  • carbon disulfide
  • mercaptans
  • disulfiram
  • N-acetylcysteine (antidote)
Shoe polish
  • nitrobenzene
  • nicotine!
Vinegar (2)
  • acetic acid
  • hydrofluoric acid
  • turpentine (urinary metabolites)

The bonus question:

Q. A bite by which Australian snake could seriously impair your performance on the ‘Sniff a Poison’ challenge?

Show Answer

Potentially any of the venomous elapids in Australia as they their bites may be lethal!

However, at least one species can specifically impair the victim’s sense of smell: the Red-bellied Black Snake, Pseudechis porphyriacus, one of Australia’s most striking and beautiful snakes.

Victims may experience permanent alterations in their olfactory sense. Abnormalities include anosmia (loss of smell), cacosmia (the sensation of a foul smell – not good), dysosmia (a distorted perception of smell) and even phantosmia (the sensation of smell without stimulus).


  • Flomenbaum N, et al (2006). Goldfrank’s Toxicologic Emergencies (8th edition). McGraw-Hill Professional.
  • Sutherland SK, Tibballs J (2001). Australian animal toxins: the creatures, their toxins and care of the poisoned patient (2nd edition). Oxford University Press.

LITFL Toxicology Challenges


Toxicology Conundrum

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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