The present invention relates to a biodegradable plastic made from a combination of at least one synthetic plastic polymer, at least one natural polymer and a natural polymer attacking agent and articles made therefrom.The present invention further relates to a method of eliminating hydrocarbon contaminating a region subjected to extreme temperatures by contacting the region with hydrocarbon-degrading microorganisms and adjusting the temperature of the region for optimum growth.The present invention also relates to a method of treating aspirin-treatable conditions comprising administering to a patient in need of such treatment a compound of Formula I ##STR1## In addition, the present invention relates to a method of protecting a philatelic item bearing a mark identifying an expert or owner of the item and possibly an additional distinguishable mark specific to the philatelic item from alteration.