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Puzzle persists for 'degradeable' plastics, India's Plastics Waste Rules ignores it

Written By krishna on Thursday, April 28, 2011 | 9:19 AM

Note:it has been noted in the light of the science and experiences in Europe that oxo-degradable bags "are merely polyethylene bags with additives that cause them to fragment, eventually." In Europe, companies producing degradable bags are now being sued, because the claims are meaningless, and confuse both the consumer (thinking they are equal to compostable bags) and the composting facility (where they contaminate feedstocks). This type of litigation is underway in CA now too, where it is illegal to market products as degradable or biodegradable, because they cannot be substantiated with scientific standards (ASTM). Only compostability can be marketed, when backed up by ASTM tests, says Rhodes, a Environmental Writer and a Organics Recycling Consultant.

ToxicsWatch Alliance (TWA) had pointed out the "Objectionable Provisions in India's Plastics Waste (Management & Handling) Rules, 2011" saying "While the myth about biodegradable and compostable plastics continues to be perpetuated by the plastics industry, it is germane to inquire whether biodegradable and compostable mean one and the same?." TWA referred to Section 2 (d) of Plastics (Manufacture, Usage and Waste Management) Rules, 2011 which defines “Compostable plastics” as "plastic that undergoes degradation by biological processes during composting to yield CO2, water, inorganic compounds and biomass at a rate consistent with other known compostable materials and does not leave visible, distinguishable or toxic residue." TWA continues to argue that there are numerous questions about biodegradable and compostable plastics that require to be addressed before making a Rule that promotes biodegradable plastics.

TWA raised questions about Section 7 of the Rule that reads "Protocols for Compostable Plastic Materials:- Determination of the degree of degradability and degree of disintegration of plastic material shall be as per the protocols of the Bureau of Indian Standards".

Even these so called compostable or biodegradable plastic will persist long enough in the environment to present many of the same potential threats as the traditional plastics.

There has been no answers to questions like "Do biodegradable plastics contain the plasticizers, such as phthalates or bishneol-A, as the conventional non-biodegrabale plastics do?"

In response, it was stated on IPEN listserve that "Regarding bio degradability, the standards for this are set up the Bureau of Indian Standards. Any definition change is to be done by them. Currenlty they are following international standards and definitions."

Question remains as to whether India's 4328 municipalities will ever have the wherewithal to check and cross-check the plastics which are supposedly biodegradable?

Gopal Krishna

Eco-friendly plastics disintegrate, but might just linger in the environment.

Daniel Cressey

plastic bag Going nowhere fast: 'degradable' plastic bags are not as helpful to the environment as hoped.Punchstock

The environmentally friendly version of polythene might not be so friendly after all.

Polyethylene is one of the most widely used materials in the world, and the discarded plastic bag has become one of the most potent symbols of human impact on the environment. As worries over the vast scale of waste from this plastic has grown, so has the use of purportedly 'degradable' forms of it.

Adding transition metals such as iron and cobalt can promote the oxidation of the ethylene polymers and claims for the degradability or biodegradability of these materials are widespread on food packaging and plastic bags. But a review published last week in Environmental Science & Technology1, notes that there is no evidence that 'degradable polyethylenes' are actually all they suggest.

Although it is clear that 'degradable' plastic bags, for example, will fall apart in the environment, the resulting fragments can persist for a long time, and there are no long-term studies on these pieces. A key issue is that products can be described as biodegradable without reference to the timescale it takes them to fully biodegrade.

"There are a tremendous number of papers about degradable polyethylene but no one has really shown a high degradation," says Ann-Christine Albertsson, a polymer researcher at the Swedish Royal Institute of Technology (KTH) in Stockholm and lead author on the critical review. "Of course they degrade in one way – they are losing part of their properties. But if you mean it as a positive for nature, that has not been proved."

Developing-world countries such as China are also starting to use 'degradable' polyethylene, says Albertsson. Indian authorities have taken an interest in the subject, and recently sent a postdoc to work with her. Although sohttp://www.blogger.com/img/blank.gifme countries are already trying to move to genuinely degradable products based on starch-based polylactide, this is still expensive. And paper-based products may not be a suitable replacement because of the requirement to cut down trees.

[rest of story at http://www.nature.com/news/2011/110421/full/news.2011.255.html]
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