• Packaging waste directive and standards for compostability

    Standards for Compostability EN 13432

    Following the development of the EU Directive on Packaging and Packaging Waste (94/62/EC), an EU harmonized standard for compostable and biodegradable packaging - EN 13432:2000 – “Packaging: requirements for packaging recoverable through composting and biodegradation”- was introduced in 2000.  It was adopted by national standards bodies in many of the European Union Member States, for example published as BS EN 13432 by the British Standards Institution, the ‘BS’ prefix meaning ‘British Standard’. Its scope is specifically compostability and anaerobic digestability of packaging. 

    Packaging products that conform to the ‘compostable’ criteria of the relevant standard are suitable for composting (the tests simulate industrial scale composting conditions) and those that conform to it’s anaerobic digestion criteria are suitable for that method of organic recovery. 

    Summary of BS EN 13432: ‘Compostable’ criteria

    Key tests and Pass / Fail criteria are:

    Disintegration – the packaging sample is mixed with organic waste and maintained under test scale composting conditions for 12 weeks after which time no more than 10 % of material fragments are allowed be larger than 2 mm.Biodegradability - a measure of the actual metabolic, microbial conversion, under composting conditions, of the packaging sample into water, carbon dioxide and new cell biomass.  Within a maximum of 6 months, biodegradation of the test sample must generate an amount of carbon dioxide that is at least 90 % as much as the carbon dioxide given off from the control / reference material.Absence of any negative effect on the composting process. Low levels of heavy metals (Potentially Toxic Elements) and no adverse effect of the quality of compost produced. Upper limits, in mg/kg of dry sample, are: zinc 150, copper 50, nickel 25, cadmium 0.5, lead 50, mercury 0.5, chromium 50, molybdenum 1, selenium 0.75, arsenic 5 and fluoride 100.The composted packaging material must not have adverse effect on the bulk density, pH, salinity (electrical conductivity), volatile solids, total nitrogen, total phosphorus, total magnesium, total potassium and ammonium nitrogen characteristics of the compost.

    Each of these tests is undertaken according to internationally agreed methods of test, as specified in BS EN 13432.  Independent laboratory test results are then compared with the strict pass / fail limits set in the standard.  Only if a material passes every ‘compostable’ test requirement is it proven to be ‘compostable’. 

    Independent certification scheme

    For many standards, including BS EN 13432, independent certification bodies offer product assessment and certification services. In the case of compostable packaging, upon receipt of an application a certification body would review the nature and ingredients of the packaging sample and ensure it is sent to an appropriate laboratory for the correct tests to be carried out.  When received, the certification body would then check whether the laboratory test results report on the packaging sample proves that it has BS EN 13432’s ‘compostable’ criteria.  If it has, a unique packaging product certification number and certificate is awarded, and it may carry the scheme’s certification mark (logo) ‘compostable’.

    In the UK, the Association for Organics Recycling operates a certification scheme in partnership with the German certification body Din Certco, aligned to the requirements of BS EN 13432.  Packaging certified to BS EN 13432 is an acceptable input material to commercial composting systems, including those that comply with BSI PAS 100 for composted products as well as the Compost Quality Protocol. 

    In order to gain certification for the packaging  comprehensive documentary evidence and product test results are essential (see figure 1).  A product e.g. an organic waste collection bag may consist of material (including intermediates), additives, e.g. colorants and printing inks and it is imperative that the final combination / product, not just its constituent parts passes all the tests. 

    To help simplify the process, certification bodies such as Din Certco maintain a “positive list” of base materials, intermediates and additives which are certified for use in the manufacture of compostable packaging products.  Once submitted, the certification committee will review all the provided evidence and if they agree that the product meets all the requirements of the relevant standard (BS EN 13432) then the product becomes certified.  Certified products or product families, e.g. a style of bags within a specified size / thickness range, are then issued a unique 7P certification number and are permitted to carry the European Bioplastics’ “compostable seedling logo”.  (European Bioplastics is the owner of the logo and licences certification bodies to award its use to manufacturers and converters of certified compostable packaging and plastics.)  Under this scheme, a product that carries the ‘compostable’ seedling logo must also display its 7P number. This allows end-users to trace the product to its source.

    A product certificate is only valid for three years after which it must be renewed if the product is to continue to use its 7P number and the ‘compostable’ seedling logo.  In addition, to ensure integrity of the whole process, at frequent intervals throughout the three year period, the certification body, in the UK the Association for Organics Recycling, will seek samples from the market which will then be sent for further testing.  This market surveillance aims to verify whether a ‘compostable’ product on the market is in fact the same one that passed the ‘compostable’ tests, with the same 7P number.

    For non-packaging plastics a ‘sister’ standard exists: EN 14995:2006 – “Plastics. Evaluation of compostability. Test scheme and specifications”.  The tests and pass / fail criteria in EN14995 are exactly the same as those in EN13432, the only difference being that it applies to any plastic material or product which is not packaging.

    Home compostable packaging and plastics

    In addition to certification to BS EN 13432, it is also possible for a product to be deemed ‘home compostable’.  At present there are no specific international or national standards for home compostable packaging and plastics, as the existing EU standards and their nationally adopted versions involve methods of test that simulate industrial scale composting and anaerobic digestion.

    A Belgian ‘OK Compost Home’ specification is managed by the certification body Vinçotte, who also operate their ‘OK Compost’ (aligned to EN 13432) certification scheme.  This specification contains similar requirements to EN 13432 but the test temperatures and durations are different – see table 1. 

    Due to the increasing prevalence of compostable packaging and plastics products in the UK market, the Association for Organics Recycling is working with a number of stakeholders to seek to establish a similar specification for the UK.  Currently, if a product claims it is ‘compostable’ then this claim is only referring to industrial compostability unless it has been certified ‘home compostable by Vinçotte displays the ‘OK Compost Home’ logo.

     Table 1:  Comparison of Industrial and Home Compostability

      Industrial Composting: BS EN 13432 Home Composting: Vinçotte Certification Programme
    Biodegradation Test performed at 58 °C +/- 2 °C, carbon dioxide at least 90 % compared with control within 6 months (approx 182 days) Test performed at ambient temperature (20 - 30 °C), carbon dioxide at least 90 % compared with control within 365 days
    Disintegration Test performed at whatever temperatures are achieved in vessels, each at least 140 litre capacity. At maximum of 12 weeks (approx 84 days) no more than 10 % of original dry weight of test material > 2 mm. Test performed at 20 - 30°C in vessels each at least 140 litre capacity. At maximum of 26 weeks (182 days) no more than 10 % of original dry weight of test material > 2 mm.
    Current certification and logos

    AFOR / Din Certco