Oxo-degradable plastic bags are also available today to substitute traditional LDPE plastic bags. The oxodegradable
plastic bags are not biodegradable but are designed to break down into small pieces after exposure to oxygen. The smaller pieces may lead to environmental problems if they are consumed by animals or if the small pieces are scattered over the ground. The “oxo-biodegradable” additives are usually incorporated in conventional plastics such as polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephtalate (PET) and sometimes also polyvinyl chloride (PVC) at the moment of conversion into final products. Narayan [53] has pointed out that oxo-degradable fragments may act to concentrate pesticide residues in the soil, as has been shown for PE and polypropylene (PP) remains found in
the marine environment [54,55]. There are also concern that degraded fragments may become cross-linked and hence persist in the environment [56]. Research into the toxicological impact of oxo-degradable additives [57] found no evidence of toxicity to tomato, cucumber or cress seeds. There is evidence that plastic debris in the marine environment can degrade to give fine particles that then become ingested and accumulate in marine organisms [58,59]. No evidence was found that oxo-degradable fragments have a harmful bio-accumulative effect but neither was there evidence that they do not. There is very little evidence for the fate of oxo-degradable fragments and this is an area identified as requiring further research.