Live shotgun shells and dead animals are some of the hazards for personnel at Wastenet Southland.
The recycling company says about 9% of material collected from yellow bins for recycling is contaminated. Dead dogs, pigs heads, and gas bottles are among such items.
Overseer Ian Beker said live shotgun shells have exploded while going through the processing machinery.
Seventy four letters were sent to offending households in July and 56 have been so far sent this month.
WasteNet may start withdrawing bin services to those who continue to misuse the system.
