Phosphine (PH3)
Definition
The toxic gas liberated when aluminium phosphide reacts with water or gastric acid. It inhibits mitochondrial cytochrome c oxidase, generates reactive oxygen species and causes severe metabolic acidosis, myocardial depression and multi-organ failure.
- Chemical formula
- PH3
- Source
- Aluminium phosphide reacting with water or gastric acid
- Mechanism
- Inhibits mitochondrial cytochrome c oxidase
- Effects
- Reactive oxygen species, metabolic acidosis, myocardial depression
Common questions
Why is aluminium phosphide poisoning particularly hard to treat clinically?+
There is no specific antidote, and because phosphine gas forms inside the body once the tablet contacts stomach acid, treatment is largely supportive, focused on cardiovascular and metabolic stabilisation while toxic effects progress.
How is phosphine exposure confirmed in a post-mortem toxicology case?+
Analysts look for characteristic garlic-like odour at autopsy, headspace gas analysis for phosphine, and residual aluminium or zinc phosphide particles in gastric contents, since phosphine itself is unstable and hard to detect once dissipated.
Why does cytochrome c oxidase inhibition explain the severity of the poisoning?+
That enzyme is essential for cellular energy production, so its inhibition rapidly starves tissues of usable energy across multiple organs, which is why aluminium phosphide poisoning can progress to multi-organ failure within hours.
Related terms
- Acetylcholinesterase (AChE)
- The enzyme that hydrolyses acetylcholine at cholinergic synapses. Inhibition by organophosphates or carbamates causes accumulation of acetylcholine at muscarinic, nicotinic and central...
- Aging
- The irreversible loss of one alkyl group from the phosphorylated AChE-organophosphate complex, after which oximes can no longer reactivate the enzyme. Aging...
- Anupam Verma Committee
- An expert committee constituted by the Ministry of Agriculture in 2013 to review 66 pesticides already banned in other countries but still...
- DUMBBELS
- Mnemonic for the muscarinic side of the cholinergic toxidrome: Diarrhoea, Urination, Miosis, Bronchospasm and Bronchorrhoea, Bradycardia, Emesis, Lacrimation, Salivation.
- Intermediate Syndrome
- Proximal muscle and respiratory weakness appearing 24 to 96 hours after acute organophosphate exposure, requiring mechanical ventilation, distinct from the acute cholinergic...
- OPIDN
- Organophosphate-induced delayed polyneuropathy: a distal sensorimotor neuropathy appearing 2 to 3 weeks after exposure to certain OPs (TOCP, leptophos), mediated by neuropathy...