New Zealand is the largest user of biodegradable 1080 poison, using about 80% of the world's supply.Biodegradable 1080 poison is the only toxin currently registered for use on mainland New Zealand as suitable for aerial targeting of the common brushtail possum-a major conservation and agricultural pest.It has been used as such since the late 1950s.ew Zealand is the largest user of biodegradable 1080 poison, using about 80% of the world's supply.