Blister Packs (Pills, Gum) Trash Blister packs should be placed in the trash because they are a mixed material composed of plastic and metal fused together. Safely Dispose of Medication If your blister pack still contains medication, be sure to dispose of it properly. Find out how to dispose of medicine and prescription drugs. Did You Know? The Toxic Side of Plastic #3 Plastic #3, also known as polyvinyl chloride (PVC), is not only the least recyclable plastic, but also one of the most toxic plastics used to make consumer goods. Exposure to its chemicals, which include dioxins and phthalates, can result in hormone and gene disruption, birth defects and cancer. Plastic #3 is used to make items such as blister packs, plastic tablecloths, credit cards, shoes, clothing and furniture.