section_path: Additives/Leaching
section_name: Leaching
paragraph_text: Leaching
  
  Additives may be weakly bound to the polymers or react in the polymer matrix. Although additives are blended into plastic they remain chemically distinct from it, and can gradually leach back out during normal use, when in landfills, or following improper disposal in the environment. Additives may also degrade to form other toxic molecules. Plastic fragmentation into microplastics and nanoplastics can allow chemical additives to move in the environment far from the point of use. Once released, some additives and derivatives may persist in the environment and bioaccumulate in organisms. They can have adverse effects on human health and biota. A recent review by the United States Environmental Protection Agency (US EPA) revealed that out of 3,377 chemicals potentially associated with plastic packaging and 906 likely associated with it, 68 were ranked by ECHA as "highest for human health hazards" and 68 as "highest for environmental hazards".