Industry and consumers have started to recognise the benefits of compostable products - preferably produced from renewable raw materials.
This is reflected in the increasing popularity of compostable products. The market is growing and the production capacities for biodegradable polymers (BDP) are rising.
Also improving are the technical standards for the determination of compostability and the certification systems built on them. Currently, DIN V 54900, EN 13432 and ASTM D 6400 are the relevant standards for the determination of compostability.
Each of these standards is being applied by a number of certification organisations in the testing and assessment of compostable products and materials. The standards are very similar in their general construction, the applicable tests and the necessary pass levels. As a rule, the assessment of compostable materials and products comprises five different parts:
- Characterisation/chemical testing
- Determination of ultimate biodegradability
- Determination of compostability (disintegration)
- Analysis of the quality of the compost
- Determination of ultimate anaerobic biodegradability (voluntary)
EN 13432 is currently the most relevant standard because it is a harmonised, mandated European standard, which gives it a special legal relevance. It is assumed that if a producer fulfils EN 13432, s/he also fulfils the European packaging directive.
DIN V 54900 is the oldest standard of its kind and still has some relevance in Germany, although most producers are now using EN 13432. ASTM D 6400 is a US standard that is important for producers who are active in the USA.
Experience has shown that due to the relatively limited knowledge about these standards, end-users or buyers of compostable materials have come across many other standards, such as:
- BS 6642 'Specification for disposable plastics refuse sacks made from polyethylene'
- ASTM D 1238 'Standard Test Method for Flow Rates of Thermoplastics by Extrusion Plastometer (Melt Index)'
- BS 6085 'Methods for determination of the resistance of textiles to microbiological deterioration'
However, none of these standards allows an assessment of the compostability of these products. Therefore, experts, leading manufacturers and certification bodies must take the necessary steps to make the existing standards on compostability - such as DIN V 54900, EN 13432 or ASTM D 6400 - known.
Benefits of certification
Having well-accepted standards is a valuable asset for compostable materials, but it might be insufficient. A potential buyer cannot see easily if a product is really compostable. Thus, compostable products might need something more than good standards, such as certification systems. Through certification, these products can obtain additional benefits such as:
- Easy recognition of products
- Faith in the new products
- More security in product liability
- Use of a known and recognised mark
The above-mentioned standards are used by various organisations offering certification schemes for compostable materials. A large number of standards and procedures are currently applied. In addition, all organisations implement various special arrangements. Globally, the Biodegradable Plastics Society of Japan is the market leader in the certification of compostable products (see Figure 1). DIN CERTCO (Germany) follows as the leading European certification organisation.
To further extend the acceptance of its certification system, the organisation has signed cooperation contracts with the Keurmerkinstituut in the Netherlands. It has also concluded negotiations on cooperation agreements with the Composting Association in the UK and the Polish state packaging institute Centralny Osrodek Badawczo-Rozwojowy Opakowan (COBRO). Negotiations with other potential partners are under way.
DIN CERTCO, BPI (USA), and BPS (Japan) have signed a cooperation contract on the acceptance of test results, which significantly reduces the testing costs for producers who are active in all three major markets (Europe, the USA and Japan). Moreover, activities for the creation of certification systems for compostable materials are currently reported from Spain (Catalunia), Korea and Taiwan.
Having standards-based certification systems in place is, of course, a prerequisite for the success of compostable products. Another important factor is consumer acceptance. Also, for the operators of waste management systems especially, the quality of the source separation of garbage has to be maintained; the consumer must be able to dispose of the compostable products in the correct way - that is, in a bio bin, based on a clear marking of the products. Numerous trials have been conducted to check the consumer acceptance, two of which in Germany.
Acceptance of compostable bio bags
In the winter 1998-99, a trial on the acceptance of compostable bio bags by the consumer and the effect of its introduction in the German city of Remscheid was conducted. The trial encompassed 2000 households. The 50 per cent constituting the test area received compostable bio bags, while the other 50 per cent, the reference area, did not receive compostable bio bags. Research was conducted through questionnaires and waste analysis. The results were as follows:
- The introduction of compostable bio bags heightened the acceptance of the biowaste collection.
- The households in the test area thought that they were collecting more biowaste than before. The most likely reason for this is that the compostable bio bags make the biowaste collection much more hygienic and comfortable. The results of the questionnaire were supported in the actual analysis of the collected biowaste. The amount of collected biowaste was indeed higher in the test area than in the reference area.
- The contamination of biowaste in several different areas of the city decreased, probably because of the average consumer's higher awareness.
Thus, the trial in Remscheid could fully prove the beneficial effects of the introduction of compostable bio bags.
Acceptance of compostable packaging
In Kassel another trial was conducted in 2000-02. This time, compostable packaging was in focus. Several different and certified products were introduced to the market in Kassel, for example:
- Dairy products
- Fruits and vegetables
- Poultry packaging
- Carrier bags and waste collection bags
- Food service items
All products were marked with the compostability mark. Obviously, one of the first questions for the consumer was if the mark was recognised. Market research date showed that this was the case. The average consumer was also able to understand the basic idea and the benefits of compostable products and thought that using compostable packaging made sense for organic produce in particular.
Overall, the consumer was happy with the quality of the products and would even be willing to pay a higher price for products in compostable packaging.
Positive effects for retailers were also observed. During a short period, one retailer in the Kassel area sold organic peppers in compostable packaging. In other branches of the retail chain, the same organic peppers were sold in conventional packaging. The compostable packaging had a notably positive effect on the sales figures.
Thus far, the Kassel trial is the largest project carried out to analyse the use of compostable products. Intensive research in use, market acceptance and waste management showed very positive results.
There was no negative effect on waste separation or compost quality and consumer acceptance was high. The contamination of the biowaste stayed within the usual limits of between 0 and 2 per cent.
A concept with potential
The results of the German model trials show that consumers recognise and like the basic concept of compostable products. Standards to determine the compostability of products are well developed and certification system to safeguard the market exist and are increasing in coverage.
This ensures one part of a good regulatory framework for compostable products, thus enabling success for compostable products.