BRIEFING NOTE on DEGRADABLE PLASTICS

Plastic is a familiar component of modern living, used in all sorts of packaging and household and commercial applications. Whilst the benefits of low cost, light weight, strength, imperviousness to gas and water, transparency, sealability, and printability are highly regarded, the very strength and durability which makes plastic such a useful and economic material becomes a major problem when disposal is required. Science has now found the answer to this problem.

OXO-BIODEGRADABLE1 PLASTIC

The most useful and economic of the new technologies produces plastic which degrades by a process of OXO-degradation. This technology is based on a very small amount of a pro-degradant additive being introduced into the conventional manufacturing process, thereby changing the behaviour of the plastic The degradation of the plastic starts immediately after manufacture and will accelerate when exposed to heat, light or stress. 

It will be consumed by bacteria and fungi after the additive has reduced the molecular structure to a level2 which permits living micro-organisms access to the carbon and hydrogen. It can therefore be properly described as “biodegradable. The material has then ceased to be a plastic and has become a food source. This process continues until the material has biodegraded to nothing more than CO2, water, and humus. It does not leave  fragments of petro-polymers in the soil. 
 
Symphony’s oxo-biodegradable bags are in fact being bought and distributed by the UK Soil Association, and used for direct contact with organic food products. Symphony’s oxo-biodegradable film has been certified3 as safe for long-term contact with any food type at temperatures up to 40°C. It is also ideal for frozen food packaging, as it can be kept for extended periods at low temperature, and will then quickly degrade when it becomes a waste product at normal temperatures. There is little or no additional cost involved in products made with this technology. 

The length of time it takes for oxo-biodegradable plastic products to degrade can be ‘programmed’ at the time of manufacture and can be as little as a few months or as much as a few years. They can be opaque vacuum-packed for delivery and will not degrade in the absence of air and light, until needed for use. Unlike PVC, the polymers from which oxo-biodegradable plastics are made do not contain organo-chlorine. Nor do oxo-biodegradable polymers emit methane nor nitrous oxide under aerobic or anaerobic conditions. 

Policymakers need always to consider what happens to waste plastic products which escape the collection net and end up as litter. It is impossible for industry and government to ensure that they are all collected, and even if collected to ensure that they are all recycled or incinerated. They should all therefore be made from oxo-biodegradable plastic, except for very long-life items. If collected they can be recycled, composted, or incinerated, and if not collected they will degrade and disappear, leaving no harmful residues. 

Products can be made in oxo-biodegradable plastic using the same machinery as currently used for conventional plastic. There is therefore no need to re-equip factories or re-train the workforce.

To read more on this report, please click here.(pdf)