The New Straits Times, August 22, 1997
Recently, the role of the plastics reduction campaign to reduce the volume of municipal solid waste was highlighted. How can the promotion of biodegradable plastics help in replacing the non-biodegradable plastic packaging?
The development of biodegradable plastics can play a crucial role in helping to solve our waste disposal problems.
Since waste reduction is important for future municipal solid waste, a number of important issues need to be addressed to ensure that the biodegradable plastics industry develops.
Today, the main obstacle to widespread use of biodegradable plastics is cost. In the United States, for example, biodegradable plastics are priced at US$2.50 (RM7) to US$6 per half kilogramme of the resin which is about five times higher than common thermoplastics.
Due to their high prices, most current applications for biodegradable plastics are in niche packaging area with unique environmental considerations.
Other factors which will be important in determining the future growth of biodegradable plastics include the following:
Regulatory actions
The development of the biodegradable plastics industry in the US has demonstrated that unfounded claims were made on the material being used as biodegradable plastics. The first generation of allegedly biodegradable, that is starch-filled polyolefins has been shown to be actually a non-biodegradable material.
This material could at best be described as biodisintegrable and not completely biodegradable.
Data showed that only the surface starch biodegrades, leaving behind a recalcitrant polyethylene material. In addition, starch entrapped within the polyethylene matrix did not appear to be degraded.
Based on this development, a number of regulatory actions resulted which, among others, define the biodegradability of a product taken as 'the properties of the material when exposed to a waste management facility that is designed to ensure biodegradation and the product at issue will safely break down at a sufficiently rapid rate and with enough completeness when disposed of in that system.'
Moreover, the breakdown products of the biodegradation process should be nontoxic and should not build up in the environment at a faster rate than they are being utilised by the microorganisms.
Incentives for research and development on biodegradable plastics
Scientific research into biodegradable plastics is important for the technology in plastic waste management to go forward.
New approaches, new products and new developments are needed to ensure further growth into this area. At the moment, Universiti Sains Malaysia has initiated a multi-disciplinary research approach to develop biodegradable plastics using locally-available resources.
The standard development activities
The issue of standard specifications for biodegradable plastics need to be conducted by an independent and well-represented committee.
The test methodology to measure the intrinsic biodegradability should take into consideration the local environmental condition as well as the local microbial organism.
A parallel test in real world systems need to be run to confirm and establish biodegradability.
To harmonise the various standards for biodegradations, evaluation of the various standards for biodegradation, evaluation of the various standards such as Sturm test for ready biodegradability, the Japanese Miti test for biodegradation, the American Standard Organisation, and the ASTM standard for intrinsic biodegradability of plastic materials under an aerobic and anaerobic environment should be performed as well.
The need to increase for composting infrastructure
Composting can be defined as 'accelerated degradation of heterogeneous organic matter by a mixed microbial population in a moist, warm, aerobic environment under controlled conditions'. It is truly biological recycling of carbon. By mixing the biodegradable plastic together with other agricultural waste, a valuable compost as the main component along with water and carbon dioxide is generated. When added to soil, it gives rise to a more complete natural recycling mechanism as compared to the present context of recycling be it aluminium can or plastic recycling.
Furthermore, the value-added compost being generated would provide additional incentive to drive the biodegradable plastics venture to success.
Integration of the material with the various waste management infrastructure
The attributes of biodegradability for a product will only make sense if the product is collected and sent to a waste management facility where the product can undergo biodegradation.
In line with the future development of the waste management system, composting, sewage and waste water treatment facilities, anaerobic digesters and active landfalls are waster management infrastructures where biodegradability is important.
Therefore, to ensure that a product meets today's environment criteria, integration of waste management with the product has to occur and evaluation on the attributes be carried out to determine whether the claim can be validated under such systems.
