Beware of washed-up toxic canisters

Canisters containing highly toxic rat poison are washing up on Australian beaches.

The Australian Maritime Safety Authority has received reports of 22-centimetre metallic canisters washing ashore along the country's east coast since 2012, most recently on western Cape York and Yeppoon in central Queensland.

They contain the industrial rat poison aluminium phosphide and when opened release highly toxic phosphine gas, which in severe cases can cause death.

AMSA says the gas could smell like garlic, rotting fish or urine.

Exposure can cause headaches, nausea, vomiting, difficulty breathing, dizziness, tightness of the chest, diarrhoea, fluid in the lungs, liver and kidney damage and death. The gas can also spontaneously ignite.

Aluminium phosphide is imported from China and Africa and AMSA suspects the canisters came from an unreported loss of shipping cargo some time before February 2012.

Queensland and NSW fire and emergency services have dealt with more than 40 of the items since 2012.

AMSA says anyone who sights any of the canisters should leave them alone and call 000.