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Tuesday October 25, 2011

Going green with biodegradable products

Biodegradable food containers are touted as a solution to our throwaway society but it appears that the answer is not that simple.

CONVENTIONAL plastics have been accused of a slew of crimes. They are said to deplete non-renewable resources such as oil and when disposed off, degrade extremely slowly, if at all. When carelessly discarded, they are an eyesore and can choke wildlife. They are also said to take up valuable landfill space.

This has led to a plethora of measures to replace plastics, especially for single-use applications, with other materials such as paper or bioplastics made of plant-based materials, like starch or complex sugars.

The central assumption behind such thinking is that paper or starch-based materials will degrade quickly and leave no trace after a few months or a year or two (common assumptions by people on what biodegradability is all about).

Switch, but carefully: There are alternatives to polystyrene disposables, but not all are independently certified to be biodegradable or compostable.

The move to replace plastics – such as shopping bags, packaging, food containers (clamshells, plates, cups, bowls) and cutlery – is currently focused on areas where they are the most visible. Penang has banned retailers from handing out free plastic bags to shoppers and disallowed food sellers in municipal council-operated hawker centres from using polystyrene clamshells and plates. Selangor is toying with the same idea.

Manufacturers of alternatives to disposable plastic foodware are quick to trumpet the biodegradability of their products. Selangor-based Greatpac, manufacturer of the Jasa Eco (jasa-eco.com) range of disposable tableware that is bio-based (a blend of 70% corn starch and 30% conventional polypropylene, or PP), said its products can be expected to degrade within five years after being landfilled.

“We are confident that 70% of the product will degrade and this is still better than totally no degradation,’’ said senior manager Douglas Tan.

The company also makes a polystyrene clamshell (codenamed JEF2) which contains additives that will make it biodegrade under low or zero oxygen (anaerobic) conditions. It clarified that while JEF2 is not a bio-based product (like its starch-based series), the clamshell can be expected to biodegrade within two to five years in local landfills (based on extrapolated lab results).

The Jasa Eco range of tableware includes biodegradable polystyrene foodware (the yellowish containers) that meets ASTM D5511-11 certification for biodegradability, and some disposable utensils that can claim to be compostable (available only for export at the moment).

Penang-based Return 2 Green (return2green.com.my), which makes clamshell boxes from agricultural waste such as sugarcane bagasse, said its products will “return to nature at 180 days of composting”.

Both companies offer products that need moisture, warmth, oxygen and microbial action to decompose, either partly or totally. This is in contrast to another range of plastic that does not need microbial action to decompose, a phenomenon known as oxodegradability (commonly seen in supermarket shopping bags, such as the ones offered by Carrefour).

Degrees of degradation

However, biodegradability itself is a debatable concept, and in the absence of a qualifying statement, a largely meaningless notion. One would be sadly mistaken if one thinks that putting the used lunchbox or plate into a compost pile would yield great results within weeks, which is what most people expect of a “biodegradable” product.

This plate — made of 70% corn-yam starch and 30% polypropylene — will be compostable if conditions stipulated under the ASTM D6400 are met in a composting facility.

The Great Garbage Project, conducted between 1987 and 1995 by a group of archaeologists from the University of Arizona in the United States, found newspapers which were still readable despite being buried for five years, and even retrieved 40-year-old newspapers from landfills, blowing away the misconception that the landfill is a huge composting facility that will take care of all biodegradable waste.

There are two types of biodegradation: aerobic (in the presence of oxygen) and anaerobic (without oxygen or in very low levels of oxygen). Aerobic degradation gives out water and carbon dioxide, while anaerobic degradation gives out methane, other than carbon dioxide and water. In the hundreds of open dumps found in the country, organic materials get piled up and create anaerobic conditions.

In properly managed sanitary landfills, such as those in North America, the law stipulates that the trash must be kept away, as much as possible, from moisture and sunlight, factors that speed up biodegradation. Hence, scientists now acknowledge that just because a material is organic does not mean that it will decompose as fast as we would like it to.

While it is clear that biodegradation cannot be taken for granted in landfills, Penang is placing its hope that the use of biodegradable foodware will somewhat help slow down the growth of waste. Its executive councillor for the environment, Phee Boon Poh, believes that such items will degrade in landfills, and help with waste management.

Whether a landfill should be managed in such a way as to speed up or retard biodegradability is still an open issue, contends Prof P. Agamuthu of Universiti Malaya’s Institute of Biological Sciences.

The bigger picture of solid waste management is a rather grim one. On a national scale, the current challenge is how to efficiently collect the 20,000 tonnes of waste that is being generated daily.

According to Datuk Dr Nadzri Yahaya, director-general of the National Solid Waste Management Department, there are presently 176 dumpsites, and many more are needed to handle the increasing amount of waste. It is understood that 11 more sanitary landfills will be built under the 10th Malaysia Plan, and five mini incinerators are expected to be running soon.

To Dr Nadzri, using biodegradable foodware is just substituting one throwaway product with another. “What benefit is there with a cornstarch plate replacing a polystyrene plate, when both are thrown out into the bin after use? Promoting throwaways is actually missing the bigger picture,’’ he said.

In countries where waste is incinerated, such as Singapore, biodegradable food containers offer no real benefits over conventional plastic disposables as waste is carted away daily to incinerators.

Disposable polystyrene foodware used and discarded during a festive open house.

Even if one is to accept the premise that biodegradable food containers will degrade anaerobically after a few years, it is doubtful whether this will lead to any real improvements in our landfills. The wet waste portion, consisting chiefly of food waste, contributes to around 45% of the average household waste (by weight), and sometimes up to 60%. This is followed by plastics (24%), paper (7%), metals (6%), glass (3%), while other miscellaneous materials make up the remaining 15%. After the extraction of recyclables, the mix that eventually gets buried in the dump contains nearly 70% food waste.

Even Greatpac acknowledges that no biodegradable food containers can degrade in a matter of weeks in our landfills, though it still argued that its products are better compared to plastics, and their decomposition under local conditions surpasses those found in North America. “Regular products may take more than 500 years to break down because they repel microbes but our products will break down between two to five years, which is still a vast improvement,’’ said Tan.

US-based company Natureworks LLC admitted that its polylactic plastic made of corn-derived sources (brand name Ingeo biopolymer, not sold here) will not biodegrade in American landfills “due to the low oxygen concentration and drop in temperature.”

Competing for food?

Some argue against using bioplastics on the grounds that the products employ food materials. Greatpac’s defence is that its products will not have an impact on the overall supply of food as it uses starch that is unfit for human consumption. “Industrial cornstarch comes from corn parts deemed not to be of high enough quality for human consumption. In that process, there is no waste as everything from the stalk to the leaves are used,” said the company on its website.

Likewise, Natureworks, a major producer of PLA (polylactic acid) plastics, said that the sugar (in the form of dextrose) used in its products is derived from corn grown for non-food applications. “Our production utilises dextrose as the base feedstock in a fermentation process which converts sugar to lactic acid. We use that lactic acid to create a polymer, which is later converted to a variety of packaging and fibre applications.

“When our plant is at capacity, Nature­Works LLC will use less than 0.05% of the available annual global corn crop. Our process does not require corn, but we only need a sugar source. This could include sugar beets, sugar cane, wheat and more. In the future we plan to move to non-food cellulosic feedstocks.”

Olive Green argued that hunger is a social phenomenon linked to poverty, and has nothing to do with crop substitution or land use patterns. “People are hungry because they are too poor to buy food. There is a shortage of purchasing power, not a shortage of food. It is not a question of whether we have enough food or how we deal with them, it is a question of how we can distribute the right food, at the right time, to the right people,” said the company on its website (olivegreen.com.sg).

Dr Theng Lee Chong, a solid waste management specialist, remains sceptical of such claims. “Starch is food, no matter if it is low-grade starch, or high-grade starch. Making food service utensils from these so-called renewable materials is akin to diverting food from the masses. Can we tell a starving African that low-grade starch cannot be eaten? And planting crops for the production of bioplastics would mean that real food crops would have to give way. There is always an opportunity cost to be paid.”

Biodegradable foodware also loses a bit of lustre when they are viewed from a life cycle inventory analysis (LCI) perspective.

The widespread cultivation of corn for plastics is not possible without a significant input of fossil fuel that comes in the form of fuel and electricity used by farm machinery, fertilisers (derived from oil), transport, and water consumption.

“From an LCI perspective, biodegradable plastics do have negative impacts, when you grow tapioca or corn just to produce it. So, the best thing is to avoid plastics in all forms and to use reusable containers,’’ said Agamuthu.

The Singapore National Environment Agency, for instance, specifies the use of reusable tableware when procuring catering services whenever possible, and encourages partners and other public sector agencies to be environmentally friendly in the organisation of events.

More methane

At the moment, the high percentage of food waste in Malaysia ends up producing landfill gas containing approximately 50% to 60% methane (by volume), and most is just vented into the atmosphere without any flaring or gas-capture systems. As methane has a global-warming potential 21 times greater than CO2, this poses a serious environmental problem. According to the national greenhouse gas inventory, landfills are the leading source of methane here, contributing more than half of this noxious emission (53%), followed by palm oil mills (38%). Seen in this light, widespread use of biodegradable foodware will in fact boost methane release.

Looking at some developed countries, a growing trend is to divert untreated organic waste like food waste, away from the landfill, rather than allowing it to ferment inside and produce methane. The European Union decreed in 2008 that untreated organic waste can no longer be landfilled. In these places, the solutions include industrial-scale composting, fermentation in digesters to produce methane for electricity, or waste-to-energy incinerators.

Some parties are already disenchanted with the promises of compostability. Early this month, the US Congress announced that 90% of the Capitol Complex’s non-recyclable solid waste, amounting to 5,385 tonnes per year, would be sent to waste-to-energy facilities soon, after an unsatisfactory experiment with composting in 2009 and 2010. The composting programme was cancelled in January; high cost was a major factor. Apparently, stocking the cafeteria with corn-based utensils and then subsequently transporting the waste to an on-site shredder only saved the amount of carbon emitted by a single car a year, but the price tag came close to RM1.5mil. Polystyrene foodware has now been reintroduced at the cafeteria.

Theng, the national co-ordinator of the Malaysia-Japan intergovernmental collaboration on solid waste management, said that the solution for Malaysia lies in concerted education on waste minimisation and proper recycling, so that more resources can be diverted from landfills in the first place.

In the light of what really happens (or is unlikely to happen) within a landfill, consumers need to be aware of marketing hype. Dr William Rathje, director of the Garbage Project, in his book Rubbish (co-authored with Cullen Murphy) summed up the situation well: “The truth is, however, that the dynamics of a modern landfill are very nearly the opposite of what most people think. Well-designed and managed landfills seem to be far more apt to preserve their contents for posterity than transform them into humus or mulch. They are not vast composters; rather they are vast mummifiers.”

As for Theng, the slew of so-called green products is an indication that unfettered commercialisation can sometimes take over the initially noble cause of creating a better environment. “Sometimes, it is just hype.”

PRICE FACTOR

USING disposable ware, biodegradable or otherwise, has its advantages, if you ask those who are in the catering industry.

“I need to deploy much more manpower if the function has to use reusable plates, cups and cutlery. It is usual for guests to leave them all over the place, and the caterer will also have to absorb some breakages along the way,’’ said Norsyaliza Mohamad, assistant manager of Arena Events & Services.

Another operator said that manpower requirements can vary by up to 40% at a large function when reusable plates and cutlery are used. “And it is not enough to bring just 1,000 plates when you are catering for 1,000. You need to bring at least 2,000 plates as people are known to leave half-empty plates all over, and will not hesitate to grab a fresh plate. Using disposables is much easier as they are light and require no washing or collection,’’ said a cook from Creative Catering.

When Sariya Yatim, owner of Dapur Emas Catering, offered to use tableware made of tapioca, her customers were not interested as they did not want to pay for the price difference compared to foam plates. “But generally, most of my clients do not request for disposable tableware as the perception is that the event will not appear classy if disposable utensils are used,’’ she said.

A polystyrene clamshell can be as cheap as 7.5 sen each, or even less for larger orders, while a biodegradable option easily costs four times as much.

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