Serv­ing biodegrad­abil­ity

The Star Malaysia - Star2 - - ECOWATCH - By MENG YEW CHOONG star2­green@thes­

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).

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. Se­lan­gor­based Great­pac, man­u­fac­turer of the Jasa Eco ( 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).

Pe­nang-based Re­turn 2 Green (re­turn-2-green. 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 oxo-degrad­abil­ity (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.

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.

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 non­food 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 (olive­g­

Dr Theng Lee Chong, a solid waste man­age­ment spe­cial­ist, re­mains scep­ti­cal of such claims. “Starch is food, no mat­ter if it is low­grade 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. Wellde­signed 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 com­mer­cial-isa­tion can some­times take over the ini­tially no­ble cause of cre­at­ing a bet­ter environment. “Some­times, it is just hype.”

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

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).

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

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.

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