PE bags less damaging to environment vs bags based on biodegradable polymers?

Bags made from Polyethylene are found to be less damaging in the environment terms when compared to bags based on biodegradable polymers currently in the market in the European region. This is an interesting finding by Germany’s Institute for Energy & Environment Research (IFEU) during a detailed life cycle analysis of plastics waste bags. The study shows that, when all environmental factors are considered, the least environmentally damaging option for plastics waste bags is to use recycled PE, followed by virgin PE. The current biodegradable options, including both petrochemical and renewably-sourced plastics, performed the worst in this analysis. Oxo-degradable bags/products have not been considered. The study looked at 20 and 120 liter plastics waste bags on the market in Germany and a 30-litre size popular in France, comparing both virgin and recycled PE resins with commercially-available biodegradable alternatives including starch and PLA-based formulations. According to IFEU, the environmental profile of each waste bag is dominated by the raw material production process, with conversion to bags and transport to point-of-sale relatively minor contributors in most cases. The environmental impact of each bag type considered in the study will be lower for thinner bags. In fact, virgin PE and recycled PE score well in environmental terms because they enable significant down-gauging. Bio degradable film of 20 liter is in the range of 15-25 microns compared to virgin PE bags of only 12.5 micron thickness. The IFEU analysis also takes into account future anticipated improvements in the biodegradable plastics sector in terms of polymer manufacturing efficiency and material performance. However, the study authors point out that none of its forecast future scenarios result in the materials outperforming PE in general waste bag applications. In a separate study, the European Plastics Recyclers Association warned that oxo-degradable polymers have the potential to do more harm to the environment than good. Oxo-degradable plastics are made to degrade in the presence of oxygen and sunlight. If these bags get buried in a landfill, they probably won't degrade at all because there is no light or oxygen. Studies of one brand in the US, commissioned by the Biodegradable Products Institute, found that breakdown is very dependent on temperature and humidity. It goes slow in cold weather, while high humidity virtually stops the process. A recent Swedish study found that polyethylene containing manganese additive stops breaking down when put in compost, probably due to the influence of ammonia or other gases generated by microorganisms in the compost. The National Association for PET Container Resources- PET being a widely used plastic packaging material. NAPCOR recently called on food companies to eschew use of these degrading chemicals in packaging until their efficacy is proven. One of NAPCOR's concerns is that unless degradable and nondegradable plastics are handled separately, they could wind up being recycled together - creating plastic products that fall apart in sunlight and air. Another potential hazard is that the substance in the plastic causing its degradation could become airborne and enter the food chain, with unknown effects. Oxo-biodegradable plastics are traditional plastics that incorporate additives which affect their chemical stability. Thus, they are identified and classified according to their chemical structure and finish together with the other plastic waste in the recycling streams. In this way, they bring their degration additives to the recyclate feedstock. As a consequence the recyclates may be destabilised, which will hinder acceptance and lead to reduced value. Studies have shown that these degraded plastics can accumulate toxic chemicals such as PCB, DDE and others from the environment and act as transport medium in marine environments. Such persistent organic pollutants in the marine environment were found to have negative effects on marine resources. The United Nations Environment Programme (UNEP) stresses that littering is a behavioural problem and must be resolved by raising environmental awareness and by the establishment of appropriate waste management systems. "Oxo-biodegradable" plastics are not specified as a solution by UNEP. Long standing efforts for the prevention of littering could actually be damaged by giving users of plastic items the impression that those items might vanish harmlessly if discarded in the environment.