The right to use the mark ofconformity"COMPOSTABLE"oncompostableplasticbagsandoncompostableproductsisgrantedonlyto those manufacturer/distributors that demonstrate that their product conforms with specificperformanceattributesandadherestotheparametersfor"compostability" as setout intheBNQdocuments,Compostable Plastic Bags - Certification Program
(BNQ 9011-911/2007) and Compostable Products – Certification Program (CAN/BNQ 0017-988).
Itisimportanttobeawarethat"compostable"and"biodegradable"arenotequivalent.Similarly,"disintegration" cannot be used interchangeably with either of these terms.
The definitions established for the purpose of the program are as follows:
Biodegradation: degradation caused by biological activity especially caused by enzymatic action leading to asignificantchangeinthechemicalstructureofamaterial.(Reference:ISO162929,section3.3)
Compostable: said of that which is capable of undergoing biological decomposition in a compost site such thatthematerialisnotvisuallydistinguishableandbreaksdownintocarbondioxide,water,inorganic compounds and biomass at a rate consistent with known compostable materials. (Reference: ASTM D 6002) .
Degradation: an irreversible process leading to a significant change in the structure of a material, typicallycharacterizedbyalossofproperties(eg.integrity,molecularmassorstructure,mechanicalstrength) and/or by fragmentation. Note: degradation is affected by environmental conditions and proceeds overaperiodoftimecomprisingoneormoresteps.(Reference:ISO16929, section3.2)
Compost: solid mature product resulting from composting (Reference: CAN/BNQ 0413-200)
Composting: managed process of bio-oxidation of a solid heterogeneous organic substrate including a thermophilic phase. (Reference: CAN/BNQ 0413-200)
Compostable plastic bags and compostable products must be compatible with the dynamics invo*ed in the composting process andnotdetractfromthephysicalandchemicalqualityoftheendproduct,compost.
In Canada, for a plastic bag or other product to claim compostable, it must:
★disintegrate by at least 90% within 84 days of the composting process
★biodegrade by at least 90% within 180 days of the composting process
★have no ecotoxicological effect greater than 10% on the germination rate of seeds and
★vegetation biomass rate
CRITERIA-Background
The process toestablishtheCanadiancriteriafortheevaluationofclaimsforcompostableplasticbagsoriginated because of plastic bags being introduced into the Canadian marketplace using compostable claims thatwerenotvalid(ie.theywerenotcompostable).
Originally initiated forQuébecpurposesbyRecyc-QuébecandtheCityofMontréal,thedevelopmentoftheCanadian Certification Program for compostable plastic bags was expanded nationally by The Composting Council ofCanadawithsupportfromtheprovincialministriesofenvironmentofNewBrunswick,PrinceEdward Island, Nova Scotia, Manitoba and Alberta.
The Bureau denormalisationduQuébec(BNQ),havinghadpastexperienceinstandard-settingforthecompostingindustry, was commissioned to coordinate the review process.
Ratherthanre-inventingthewheel,thereviewprocessinvo*edtheexaminationofexistinginternationalstandards for compostable plastic bags and evaluating their appropriateness forCanadianconditionsaswellascompostingfacilityoperationalandproductmarketingrequirements.
A15-personreviewpanelwasselectedinvo*ingrepresentativesfrommunicipalities,compostingfacilities,product suppliers and users as well as consumer groups. Following extensivediscussionaswellaspublicconsultation,theCanadianCertification Programbecameofficial inSeptember2007.
In 2010 thecertificationprogramwasexpandedtoincludecompostableproductsofalltypes,followingtheadoption of the standard CAN/BNQ 0017-988. This serves to adopt the standard ISO 17088 as the national standard forCanada. Itisimportanttonotethattheoriginalprogramforthecertificationofcompostable plastic bags (BNQ 9011-911/2007) will soon be cancelled to be replaced entirelybythecertificationprogramforcompostableproducts(CAN/BNQ0017-988).
Time andrateofdegradationanddisintegrationwereamongstthecriteriaestablished.Requirementsforthebags' impact on the finished compost from the perspective of visual quality as well as trace elementcontentandplantexotoxicityhavealsobeenestablished.Thefinal set ofcriteriaselectedreflects theoperational and regulatory realities which composting facilities must adhere to in Canadaforbothorganicresidualsprocessingandfinishedcompostproductsale.
Thosemanufacturers/productrepresentativeswishingtoadheretotheCanadianCertificationProgramandusethecompostable mark of conformity on their compostable plastic bags must submit an application to the BNQfor reviewandmeettherequirementsoftheprogram.
Two review options are available:
- Submit existing compostability test results from internationally-
recognized laboratory organizations. These will be reviewed by the BNQ to confirm adherence to the Canadian Certification Program. - requesttheBNQtoconductthetestingininternationally-recognizedlaboratoryorganizations of the selected product according to the criteria set out in the Canadian Certification Program.
Bothoptionshavecostsassociatedwiththem.Themanufacturer/productrepresentativeshouldcontacttheBNQdirectly for further details.
Documentation
Copies of the certification program documents for compostable plastic bags BNQ 9011-911/2007 and for compostableproductsCAN/BNQ0017-088andthecertificationprotocolBNQ0017-988associatedwith these programs can be ordered directly on the BNQ website.
ABOUT COMPOSTING
What is Composting?
Compostingisanaturalprocesswherebymicro-organismstransform organic waste materials into a soil- like product called humus (pronounced"hue-mous").Kitchenscraps,leavesandyardwaste,paper,wood,food-processingwastes, aswellas agriculturalcrop wastes and animal manures, are excellent organic waste materials that can be composted.
Composting has a wide range of benefits:ithelpstoreducetheamountofwastegoingtolandfillsandproducesa valuable product, compost, of benefit to soil health & vitality in addition to many other attributes such as waterandsoilconservation.Itisestimatedthatabout40to60percent of thetotal wastestream could be composted!
For the composting process toworkbest,itisimportantthatthemicro-organismshaveacontinuoussupplyoffood (i.e., organic wastes), water and oxygen. As well, managing the temperature of the composting material isimportanttomaketheprocesswork.
Although most organic wastessupplyallofthenutrientsnecessaryforthemicro-organismstogrow,theygrowbest with certain levels of carbon (C) and nitrogen (N). Paper, leaves and wood are high in carbon, whilegrassclippingsandvegetabletrimmings arehighinnitrogen.The materialsinthecomposting"recipe"need to be mixed in the correct combination to create the right C:N ratio.
Types of Composting
Compostingcanbedoneinmanydifferentways.Typesofcomposting range from residential or backyard composting to mid-scale and central municipal or industrial compostingsystems.Selectingthemostsuitablemethoddependsontheamountandtypeoforganic materials to be composted.
Residential or backyard compostingmeansthatanindividualhouseholdcompostsmostofitsfoodandyardwastein a container located outside the home. Worm composting is a viable option to compost kitchen waste indoors.Compostingathomeisthesimplestandmostcost-effectivemethodbecausecollection,transportationand costs are avoided. People benefit directly from their own efforts by producing a valuableadditivefortheirowngardensoil.
However, not all food andyardwastecanbemanagedsosimply.Organicmaterialfromcommercialsources,suchas restaurants, supermarkets, apartment buildings and food manufacturers, needs to be manageddifferently.Thisiswheremid-scaleandcentralizedcompostingfitsin.
Bothmid-scaleandcentralizedcompostinginvo*essignificantlylargerquantitiesandalargervarietyoforganic wastes.
Mid-scale composting is the on-site managementoforganicwastegeneratedbyagroupofpeople,suchasinanapartment complex, office building or hospital. This avoids the transportation of organic waste. Centralizedcompostinginvo*esthecollectionandtransportationoforganicmaterialstoaspecialfacilitywhere it will be prepared and processed into compost.
Centralized Composting Facilities
The design and set-up of a centralized composting site must take into account such factors as the type and volume of organicwaste,wastecollectionmethods,sorting,storagefactorsandtheenduseforthefinished compost. Quality organic waste and good operating procedures ensure the production of high-quality compost.
Amongthemostcommoncentralizedcompostingprocesstechnologies,inorderofincreasedtechnology,are:
Windrows
Organic materials are placed in long triangular rows called windrows. Windrows are turned and watered occasionally to ensure thatthemicro-organismsgetanadequatesupplyofoxygenandthatanyclumpsoforganic material are broken up.
This method is commonlyusedforcompostingleafandyardwaste,commercialfoodwastes,orsuch"specialtyitems" as shredded Christmas trees.
Static Aerated Pile
Organic waste materials are formed into windrows over perforated pipes. Rather than the windrows being turned, air is supplied to the micro-organisms through the pipes.
Almostallmunicipalitiesownthenecessaryequipmentrequiredforcentralizedcompostingoperationsusingwindrows or static aerated piles. This means that the capital costs are relatively low.
In-Vessel
In-vessel systems are either fully or partially enclosed, and can handle more material in a smaller space than windrows or staticaeratedpiles.However,theytendtobemorecostly.Thesesystemsprovidebettercontrol of aeration, temperature and the moisture in the organic materials being composted, all of which resultinfasterdecomposition.
If necessary, water can be added tomaintainthecorrectmoisturelevel,andaircanbepumpedintoprovideoxygen and to control the temperature.
Although differentin-vesselsystemsareavailable,theyaregenerallyofthreebasictypes:channelsortroughs, containers and rotating drums (sometimes called tube digesters).
Channels (or Troughs)
The composting process takes place in long rectangular troughs or channels. The organic waste materials are mixed so that the clumps are broken up and the material is aerated.
Containers
Composting takes place in closed containers that are supplied with air. Excess moisture and exhaust air areremovedfromthecontainerstomaintainidealconditionsforthemicro-organismsthroughouttheprocess.
Rotating Drums (Tube Digesters)
Organic waste materials are added to a drum which is continuously rotating. The rotation ensures that the micro-organisms are constantlysuppliedwiththeoxygentheyneedandthatalloftheorganicwastematerials are exposed to them. The material remains in the drum for three to five days and is then transferred to windrows for finalcuring.
Anaerobic Digesters
Organicwastematerialscanalsobedigestedinanoxygen-free, or anaerobic, environment by micro-organisms that do not need oxygen. The length of timerequiredtodigesttheorganicwastemateria*ariesaccordingtotheindividualtechnologyusually between two and twenty days. The process produces humus, methane and carbon dioxide. The methaneiscapturedandconvertedintoenergy.Followingdigestion,thehumuscanbetransferred towindrows or another method for final composting.
Excerpts fromCentralizedCompostingHelpingToCompleteTheCarbonCycle,writtenbySusanAntlerofThe Composting Council of Canada on behalf of Environment Canada.