Plastics consumption totaled to about 170 million tons in 2005 and continues to show a healthy growth of more than the global GDP (about 4-5% compared to 2-3 % GDP growth). With about 35% of its consumption being in packaging, plastics more often ends up faster in municipal waste as well as on public places or roads etc. Being lighter in weight compared to other conventional packaging material, it spreads all over making the environment very dirty. Furthermore, the littering habits of humans with limited literacy particularly from the developing nations, causes the thinner and light weight plastics products such as film and even PET bottles to clutter roads, beaches and parks. Being lighter and having higher volumes compared to their weights, they often tend to clog drainage etc., causing flooding. Flooding that happened in Mumbai, India during July 2005 was mainly due to very heavy rainfall. But plastics film was blamed because it choked the drains; not allowing floodwater to get drained into the sea. This has resulted into tighter civic laws - possibly of permitting only thicker bag (greater than 50 micron) to be used in future.
One solution for restricting such environmental problem is to convert plastic that is nothing but solidified oil to degradable product that ultimately mixes with soil and produces harmless byproducts not causing any environmental problems.

Degradation is the process that would destroy plastic product partially or completely. Generally degradation of plastic is considered detrimental as it reduces the usefulness of plastic. Additives such as antioxidants for all polymers and heat stabilizers for vinyl polymers are required to be incorporated in order that these polymers remain stable during their service life. Among all applications, packaging has a very short life cycle of as little as 3 months to as high as 1 year. After that plastic packaging products cease to be useful. They not only damage the environment but also could upset the ecological balance.

Besides degradation, there are other means to make the plastics disappear without damaging environment. The first method that was used very extensively from the beginning and is still employed in many countries all over the World is called �Land filling�. In this process, the plastic product after its service life, is put into the land. However as time elapsed the land available for such purpose got reduced drastically.
The second alternative is to utilize the calorific value of plastic and put it in incineration. However, typically the municipal waste of plastic contains vinyl product that corrodes incinerators due to the presence of halogen (chlorine). Separation method can be used to separate heavier fraction of vinyl from the rest of plastic waste but it costs more. This method seeks the energy from energy rich plastic (solidified oil molecules). While this possibly is the best option, it requires a large amount of plastics at one place to achieve the optimal level of use. The transportation of plastic product for such use increases cost.
Degradation is therefore considered to be the safest and possibly one of the best alternatives. Degradation of plastic can be achieved by several methods. Oxygen, light, heat and ultra violet rays are some of the means by which degradation of plastic can be achieved.

The most useful and economic of the new technologies is wherein plastics 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 molecular structure has been reduced by the additive to a level which permits living microorganism access to the carbon and hydrogen. It can therefore be properly described as �biodegradable�. The material then ceases to be a plastic and becomes 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.
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 or nitrous oxide under aerobic or anaerobic conditions.
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.

Oxo-biodegradable plastics are made from a by-product of oil refining. Though oil is a finite resource, this by-product arises because the world needs fuels and oils for engines, and would arise whether or not the by-product were used to make plastic goods. Unless the oil resources are left under the ground, carbon dioxide will inevitably be released, but until other fuels and lubricants have been developed for engines, it makes good environmental sense to use the by-product, instead of wasting it by �flare-off� at the refinery and emitting carbon dioxide to atmosphere at that stage. As the labour, cost, and energy required to produce the raw material for oxo-biodegradable plastics is going to be incurred anyway in the production of fuels, it cannot properly be attributed to oxo-biodegradable plastics in a Life-cycle Assessment.

Hydro -biodegradable or �starch-based� plastics made from agricultural produce are not a preferred alternative. They are not really �renewable� because the process of making them from crops is itself a significant user of hydrocarbon energy and a producer therefore of greenhouse gases. Hydrocarbons are burned by the autoclaves used to ferment and polymerize material synthesized from bio chemically produced intermediates (e.g. polylactic acid from starch etc); and by the agricultural machinery and road vehicles employed; also by the manufacture and transport of fertilisers and pesticides.
Hydro-biodegradable plastic emits methane and carbon-di oxide (which are both greenhouse gases) when it degrades, and does so much more rapidly than oxo-biodegradable plastic. Methane is 23 times more potent for global warming than CO 2 . Hydro-biodegradable plastic also contains a proportion of synthetic plastic derived from oil. It is sometimes described as made from �non-food� crops, but it is in fact usually made from food crops such as maize.

Also, for the reasons mentioned below, oxo-biodegradable products are in many respects more useful and cost-effective than degradable products made from agricultural ingredients.

Test results have demonstrated that oxo-biodegradable plastic produces no immediate or cumulative adverse effects on the soil, whether from the plastic itself or from peroxidants, plasticisers, surfactants, pigments, metals or lubricants. The major elements of these latter materials are naturally bio-degradable, and the traces remaining after degradation are in such minor parts per million (in some cases, per billion) that no harmful effects will occur. These materials can of course also be found in starch-based products.

Starch-based plastics are known as �hydro-biodegradable.� They degrade by a process that emits carbon dioxide rapidly to the atmosphere. As compared with hydro-biodegradable, the oxo-biodegradable plastics have the following advantages:
•  They will degrade in any outdoor or indoor environment, even in the absence of water. This is a very important factor     in relation to litter, because a large amount of plastic waste cannot be collected. Most of the hydro-biodegradable     plastics need to be in a highly microbial environment such as a compost heap before they will degrade.
•  Oxo-biodegradable plastic can be programmed at manufacture to degrade within a timescale to suit the user's     requirements. The rate of degradation of hydro-biodegradable plastics cannot be controlled.
•  Oxo-biodegradable plastics are stronger and more versatile.
•  They are much cheaper
•  They are thinner, and use less space to store and transport, and less material to produce
•  They can be transparent, so that the food or other contents within can be clearly seen.
•  They can be recycled and can be made from recyclate. Hydro-biodegradable plastic cannot be made from recyclate,     and cannot be recycled unless extracted from the plastic waste stream and treated separately.
•  They can both be composted, but because the carbon is released more slowly from oxo-biodegradable plastic, the     carbon becomes a food resource for growing plants.
•  Bags made from them do not leak
•  Less energy is required to produce and transport them.
•  No genetically-modified ingredients
•  They do not emit methane
•  No residual plastic particles
•  No organo-chlorine
•  Safe for direct food contact
•  Ideal for frozen food because they can be kept for long periods in sub-zero temperatures and will not start to degrade     rapidly until the frozen food has been used and the wrapper has become waste.
•  They can be used in high-speed machinery (such as for bread packaging) but the performance of     hydro- biodegradable plastics in these machines is not acceptable.
•  They can be incinerated with much higher energy-recovery than hydro-biodegradable plastic
•  They can be made with the same workforce and machinery as conventional plastic products, but hydro-biodegradable     products are made by a quite different process.
•  It seems wrong to divert agricultural resources away from food production when there is so much hunger in the world,     and to use fertilisers and pesticides unnecessarily

The Report mentioned above on �The impacts of degradable plastic bags in Australia� prepared by ExcelPlas/ Nolan-ITU on 11 September 2003 for the Australian Government noted at 7.3 that:
• degradable polymers with starch content have higher impacts upon greenhouse due to methane emissions during landfill degradation and N 2 O emissions from fertilizing crops.
• degradable polymers manufactured from renewable resources (e.g., crops) have greater impacts upon eutrophication due to the application of fertilizers to land

Oxo biodegradable plastic is available in the following products:
•  Carrier bags or �shopper-bags� which consumers use to take away their purchases from the shop
•  Refuse sacks, which consumers buy in rolls at the shop, and use for disposal of their ordinary household waste.
•  Organic waste bags, similar to (b) above, which consumers use to dispose of their organic waste
•  Aprons, for the protection of garments, in the home, hospitals, restaurants, workshops etc.
•  Bags to contain dog faeces collected in parks, gardens, etc
•  Bin liners
•  Gloves
•  Hospital laundry bags in which soiled laundry can be put directly into a washing machine inside the bag
•  Plastic sheeting for a variety of applications in agriculture and horticulture.
•  Plastic film for wrapping newspapers and magazines.
•  Bread bags
•  Frozen food bags
•  Wrappers for cigarette packets
•  Shrink-wrap and pallet-wrap
•  Rigid products such as bottles and cups (currently in development)
•  �Bubble-wrap�

More products will become available in due course.

Oxo-biodegradable plastic can satisfy American Standard ASTM D6954-04 for Plastics that Degrade in the Environment by a Combination of Oxidation and Biodegradation. It can also satisfy draft British Standard 8472 for Compostability (including biodegradability and eco-toxicity) of packaging materials based on oxo-biodegradable plastics.
There is no European Standard for degradable plastic except EN 13432, but this standard applies only to composting of plastic packaging . It is not appropriate to oxo-biodegradable plastics, and was written before they became popular.
In November 2004 a major conference was held in Brussels at which scientists from around the world acknowledged the benefits of oxo-biodegradable plastic and recognised that a European standard was needed for plastics that degrade by a process of oxidation.

Oxo�biodegradable plastic made mainly from polyolefin polymeric material is now very widely accepted all over the World. It is manufactured by Symphony Polymers of UK.
It is available in India by its agent called Priti Plastics Pvt Ltd., Phone: +91-22-28614929 / 28637432, Email: contact@pritigroup.com