ingenieur Vol.87 July-Sept2021 Vol 87 2021 | Page 55

Styrofoam - > PP or fibre boxes
Plastic straw - > paper straw
Conventional plastic bags - > degradable bags
� It is misleading to say that styrofoam cannot be recycled . Styrofoam can actually be fully recycled , just that it is often not recycled because it is too lightweight and not feasible economically in terms of logistics ( imagine you are transporting > 95 % of air ).
� Polypropylene ( PP ) boxes can be a better alternative only if the PP box is cleaned up after use and segregated for recycling . Otherwise , it will end up at the landfills , and the impact could be worse because it is heavier . Both are plastics that will stay in the landfills for centuries .
� Boxes made from fibre are generally coated with a layer of plastics , and thus they are still not recyclable and not fully degradable . The carbon footprint could also be higher due to heavier weight and production footprint .
� Plastic straws should be avoided if not necessary , although there is the possible concern about hygiene from direct contact with the cup / glass .
� Use of paper straw as replacement is inexplicable , as the paper straw is coated with plastics or wax or unknown materials , which makes the straw not recyclable . Conventional plastic straws are fully recyclable if properly segregated .
� Even worse , there is no control on the quality of paper straws in the market to ensure it is a food grade product , especially from health perspective whether there is any use of colouring , bleaching agent or chemicals .
� Using a metal straw could be the most reasonable replacement but it is questionable how many people will carry a metal straw around in the pocket .
� There are many replacements for conventional plastic bags now in the market , whether they are “ degradable ”, “ biodegradable ” or some claim to be “ oxodegradable ”.
� Oxo-degradable bags are particularly confusing because it is physically impossible to differentiate whether bags are oxo-degradable or just normal plastic bags printed with the word “ oxo ” on them .
� Plastic bags made of food starch ( such as corn or tapioca starch ) are degradable for sure , but probably it makes more sense to feed the starch to people rather than making them into plastic bags , considering that the world hunger has increased to more than 100 million in 2020 .
� Any degradable plastic mixed in the waste stream will distort the entire effort to recycle conventional plastics , unless they are completely segregated out from the plastic waste stream .
� One better option is to use “ recycling bags ” made from non-woven fibre as a replacement for “ plastic ” bags . However , non-woven fibre is actually also made of non-recyclable plastics . Thus , the bags should be used as many times as possible , as otherwise it will not be more environment friendly .
Table 2 : Replacement for plastic products
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