The Protocol on Environmental Protection to the Antarctic Treaty
The Madrid Protocol - Main Points - 11 slides

8 - Banned Materials - Some materials are completely banned from Antarctica, these include:

Polychlorinated biphenyls, PCBs - which have a range of health effects in wildlife and can be passed along food chains.

Polystyrene packaging beads - Antarctica is the windiest continent, these lightweight items could easily be blown away and spend decades or longer in the environment resisting breakdown.

Pesticides - there have been a few occasions where insect infestations have affected research stations, pesticides are not  permitted as they can be harmful to the environment, entering and persisting in food chains.