Correcting point of view for article titled “Oxo degradable plastic bags disastrous to environment”

On August 20, 2018 an article appeared in the prestigious daily DAWN newspaper with the title “‘Oxo degradable plastic bags disastrous to environment’” (https://www.dawn.com/news/1428026).

The following is a correcting point of view for the article.

On August 20, 2018 an article appeared in the prestigious daily DAWN newspaper with the title “‘Oxo degradable plastic bags disastrous to environment’” (https://www.dawn.com/news/1428026).

The following is a correcting point of view for the article.

The article published in DAWN Newspaper on 20th August 2018 shows lack of understanding on the topic of oxo-biodegradable technology, compostable technology as well as use of paper and cloth bags by the contributors. The article repeatedly mentions oxo-degradable instead of oxo-biodegradable plastic products.

The Sindh Environment Protection Agency through the Sindh Environmental Act 2014 has banned use of conventional plastics and only allowed use of oxo-biodegradable products. Oxo-degradation means “degradation resulting from oxidative cleavage of macromolecules (CEN TR 15351)” whereas Oxo-biodegradation means, “degradation resulting from oxidative and cell-mediated phenomena either simultaneously or successively (CEN TR 15351)”. Oxo-biodegradable plastic is “a polymer capable of oxo-biodegradation”.

Oxo-biodegradable technology is being used worldwide including in United Arab Emirates, Oman, Kingdom of Saudi Arabia, China etc. The writer has a wrong understanding of the natural biodegradation process. The article quotes that “..do not completely disintegrate..”. This is a false and misleading argument. Oxidative degradation of polymeric and organic matter is the most common phenomenon for biochemical degradation on earth. Everything in nature disintegrates into constituents by initial chemical reaction. This includes metal, aluminium, plastic, natural polymers found in wood, paper etc.

Secondly, after the fragmentation or as the news article says “tiny particles”, the process of biodegradation continues. The oxo-biodegradable process initially induces oxidation of the polymer during which chain scission produces low molecular weight fragments, which are oxidised and hydrophilic. Those molecular species are then available as carbonaceous food sources for microbes. Microbes digest these species to not only produce CO2 but to use a material for cell growth and conversion to humus in a similar manner to wood and leaf matter. It would also be worthwhile to think how does wood, textiles or anything in the world biodegrades? They fragment into smaller pieces before their molecular weight reaches a certain point where they become food source for microbes. Almost everything on earth biodegrades in the same manner including starch based products, oxo-biodegradable products, paper products and cloth products.

Thirdly, the article suggests “…impacting the soil’s fertility…” is as well incorrect. The residues during the complete oxo-biodegradation process in soil do not contain any toxic substances and have shown no negative effect in the OECD guidelines for testing the eco-toxicity.

Additionally the use of “…starch based plastic..” is also a misleading statement. Natural based polymers are as well chemical polymers which as well initially, disintegrate and finally biodegrade. The only difference is the initiation of the hydro-degradable polymers is by hydrolosis and with an oxo-biodegradable system by a catalytic oxidative process. One can see below:

BASF (One of the largest producers of starch based plastic) quote: as of minute 1:56 down the official video:
“…the remaining fragments of the polymer molecules become smaller and smaller until they can be digested by the microorganisms…broken down into CO2, H2O and biomass…”

Exactly the same process like oxo-biodegradation!

In view of the information cited above, which is taken from the public domain, one is made to think whether the promotion of PLA based (starch based) technologies, which is considerably more expensive and involves billions of dollars in terms of production plants, is to cater to the interests of these multi national corporations who otherwise have been unable to make their presence felt?