The Auckland Council has successfully prosecuted a householder after a rubbish collector was hurt by a broken glass, and has two more prosecutions pending.
The council says the householder was ordered to pay $250 in reparation to the collector, whose hand was seriously injured by a broken tumbler.
Two other cases are in the pipeline after rubbish collectors suffered cuts to their legs caused by broken glass and a dinner plate.
The council says unwrapped sharp objects such as glass, needles and broken ceramics also pose a danger to other residents and animals once the bags are on the kerb.
It is warning people to wrap such objects before putting them in their bags. The maximum penalty for not doing so is $20,000.