The subject of oxo-biodegradation is gaining popularity in Russia: the more and more domestic companies produce packaging that decomposes in 2-3 years. The reasons are - worsening of sustainability problems and simplification of such products’ manufacturing technologies. Thus the market faces offers from Russian manufacturers of oxo-biodegradable additives. But do really all additives have the same value?
Technical Manager of
JSC International Plastic Guide,
It should be noted that at the moment all certified oxo-biodegradable additives represented on the Russian market - are imported. There are only eight companies in the world that manufacture this type of polymer products. The largest of them are EPI (Canada), Symphony (England), Willow Ridge (USA). The matter is that with all simplicity of applying such additive, just the process of its developing and testing - is complex, multistaged, requiring years of researches.
In Russia, Ukraine and Belarus are still working on development of oxo-biodegradable additives. There are some first bids for success, but they require thorough verification. And it will become possible to talk about applicability of domestic additives only after the companies-inventors will repeatedly trace biodegradation process from beginning to the very end, accumulate statistics, examine how oxo-biodegradable additive interacts with different polymer types and in different formulations; how it is affected by other additives that are included, for instance, in films; how the end product decays depending on climatic conditions and in different media. These studies will take over several years. And above all - Russian, Ukrainian, Belarusian manufacturers of oxo-biodegradable additives should undertake the complete cycle of trials and get from the relevant authorities certificates on the products’ efficiency and safety.
At the moment there exist only foreign standards – of such organizations as, for instance, ASTM (American Society for Testing and Materials). Domestic certification authorities cannot issue such certificates. We do not have yet any relevant state standards or other standards, there are no approved research methods, no statistics. But all these are obligatory, as soon as oxo-biodegradable additive must at least be nontoxic, products of it must have permission on food contact and, foremost - the packaging containing additive should fully decompose in the environment within certain period (usually from 2 to 5 years). There should not be undecomposed fragments, except a small amount of carbon dioxide, water and biomass (microorganisms).
As is known, oxo-biodegradation is a two-stage process. The first stage – decomposition via oxidation, the second one – biodegradation under the influence of microorganisms. The foreign companies research every stage and get separate certificates on the decay processes caused by oxidation and biodegradation. It is not too difficult to disintegrate polymer into fragments within oxidation process, but to launch, properly conduct and complete biodegradation, getting in result the safe residues (carbon dioxide, water and biomass) – this can be done only with approved qualitative additives.
To date, due to the small market capacity of oxo-biodegradable additives, we can hardly expect many new players on it - both foreign and Russian – with qualitative products. Therefore the proposals coming from the new little-known companies must be treated with precautions, as applying of non-certified oxo-biodegradable additive might cause anything. It might contain toxic impurities and cause harm to human health or – after decay – to environment. Packaging will decay into small fractions not suitable for bacteria food, and biodegradation process will stop. Or decay will not occur within the specified period but, say, too quickly. Imagine -consumer will carry products from a store in a new plastic bag, and it starts to break down already on a way. At last, new additive may simply not work!
For comparison: EPI, the company-inventor of oxo-biodegradable additive (EPI’s official distributor in Russia – the EcoSafe company), currently has in its arsenal about 35 grades of products for variety of formulations based on PE, PP, PS (various functional additives are also included). And for already 20 years the company continuously tests and improves its products.
EPI has express-laboratory where experts examine how decay will go in the customer supplied samples of products with specific set of pigments and additives. For example, light stabilizers inhibit the affect of oxo-biodegradable additive, and such factors should be considered.
Additives of EPI have several certificates of different countries (U.S., Canada), allowing contact with food products and medicines. Besides, each type of oxo-biodegradable additive was investigated for several years: experts observed how packaging decomposes in the cold and hot countries, in the wet and dry climate, in soil, water, on landfills.
The effectiveness of oxo-biodegradation of EPI additives (DCP128 and others) is estimated in accordance with ASTM standards. For the first degradation stage these are the standards ASTM D5272 (Standard Practice for Outdoor Exposure Testing of Photodegradable Plastics) and ASTM D5208 (Standard Practice for Fluorescent Ultraviolet (UV) Exposure of Photodegradable Plastics)). For the second stage - ASTM D6954-04 (Standard Guide for Exposing and Testing Plastics that Degrade in the Environment by a Combination of Oxidation and Biodegradation).
Safety of additives and degradation products was examined with special thoroughness. Say, the results of biodegradation of polyethylene products containing oxo-biodegradable EPI additives (DCP128 and others) show that there persist 65-75 percent of mineralization products (i.e. carbonic acid, converted from carbon by bacteria) and 10-15 percent of cellular biomass, also formed of carbon. Tests confirmed that EPI additives do not contain heavy metals, including lead, arsenic, mercury, cadmium, selenium, barium, chrome, nickel, antimony and silver. They also do not have residues like metabolites, undecomposed or inorganic substances that have a negative impact on vegetation, earthworms, or the inhabitants of freshwater bodies.
Approximately same investigation schemes of additives are used by the other leading manufacturers - Willow Ridge, Symphony and others.
It must be clear that the companies, having spent many years on research and development, patent their inventions and keep their formulations in secret. And domestic producers who want to join the first ranks, need to pass their own way from development of formulations to very thorough researches.
OPINION OF PROCESSOR
Alexander Minin, General Manager
of EvroBalt company (www.EuroBalt.ru):
- As a manufacturer of packaging, not so long ago I was offered by Russian inventors an “oxi-biodegradable” (as they named) additive, whereas for me only oxo-biodegradable additives are known, derivative of “oxo-” – oxygen.
Comes to curiosities: they write that “oxi-biodegradable bags are made of natural feedstock”! This thesis not speaks well for them: either they do not realize what produce, or deliberately mislead customers. Bags of natural materials may be subjected to hydro-biodegradation, but nowise to oxo-biodegradation. Homegrown manufacturers claim that their additive is analog of a known foreign additive (e.g., d2w), but a cheaper one. However, first, oxo-biodegradable additive is not that expensive. Second, and most likely, the use of someone else’s trademark in order to promote own products violates certain laws, as international and so also Russian.