Scientists racing to tackle plastic pollution have created a surprising new contender: a biodegradable packaging film made partly from milk protein. Researchers at Flinders University blended calcium caseinate with starch and natural nanoclay to form a thin, durable material designed to mimic everyday plastic. In soil tests, the film fully broke down in about 13 weeks, pointing to a realistic alternative for single-use food packaging.
Milk based plastic was one of the first man made plastics produced back in 1890. Not 1980, 1890.
https://en.wikipedia.org/wiki/Timeline_of_plastic_development