This Ruling replaces that published on 5 September 2018. The Ruling remains Upheld but with revised wording incorporated into the Response, Assessment and Action.

Ad description

A product page for dog waste bags on, seen on 2 March 2018, featured text which stated "Refill Poop Bag Rolls...These thick waste bags are biodegradable to lessen your dog's impact on the environment".


The complainant, who believed that the bags were made of a material that was not capable of biodegradation, challenged whether the claim "Refill Poop Bag Rolls...These thick waste bags are biodegradable to lessen your dog's impact on the environment" was misleading and could be substantiated.


Ancol Pet Products Ltd said that their bags were produced using a controlled-life plastic technology, which was added during the manufacturing stage of production of their bags. They stated that the material used converted everyday plastic products into materials that were biodegradable in the open environment. Ancol said their bags were oxo-biodegradable because they contained an additive which catalysed the degradation process in the presence of oxygen, so that plastic broke down much quicker than ordinary plastics. They said this process meant that the product was converted to organic material, which was then bio-assimilated by bacteria. The timescale for complete biodegradation, therefore, was much shorter than conventional plastics.

The manufacturers of the bags (Symphony Environmental Ltd) and the trade association for the biodegradable plastics industry (the Oxo-Biodegradable Plastics Association) provided a range of material, including scientific studies and opinions, which they believed substantiated the claim that the product was biodegradable. The evidence included: composition analyses of the bags by an external laboratory; a study on thermal and UV degradation of polypropylene with pro-oxidant; research on the colonisation of non-biodegradable and biodegradable plastics by marine microorganisms; an investigation into the biodegradation of plastics by certain bacteria; an opinion on the conclusions which should be drawn from a range of scientific material relating to oxo-biodegradable plastic technology by a leading barrister (QC); a report from the Vice-chairman of Technical Sub-committee D2:96 at American Society for Testing and Materials (ASTM) and who was one of the authors of the testing protocol for oxo-biodegradable plastics (ASTM D6954); and a further report from a leading polymer scientist.



The ASA considered that consumers would expect that in order to dispose of their dog waste bags responsibly ‒ as called for expressly and by implication (with pictures of litter bins) in the advertiser’s own packaging ‒ they should use bins provided specifically for the purpose of dog waste disposal in open spaces, such as parks, or other general waste bins. In that context, we considered consumers would understand from the claim “These thick waste bags are biodegradable to lessen your dog’s impact on the environment” that by swapping conventional plastic dog waste bags for the advertised product and disposing of fouled bags responsibly, they would be reducing their impact on the environment.

We consulted Defra over the topic of oxo-degradable plastics. We understood from Defra that oxo-degradable plastics left in the open environment ‒ where they were exposed to light and oxygen, such as in parks or other open spaces ‒ broke up into smaller fragments more quickly than conventional plastics, and that biodegradation of those plastics could only occur once they had fragmented. We also understood that there were concerns that plastic fragments and smaller, microplastics were left behind, which could have a harmful effect on the open environment, and in particular marine life. This was one of the concerns behind a proposed Directive (2018/0172 (COD)) on the reduction of the impact of certain plastics on the environment. However, we understood that the biodegradable plastics industry vigorously contested the inclusion of such products in the Directive.

We also took independent expert advice on the issue of biodegradability and the evidence provided by Ancol and the manufacturer of the additive. We understood there was a scientific consensus on the meaning of the term ‘biodegradable’ that was non-sector or product specific. It meant only that the material was amenable to microbial decomposition. It said nothing about the required environmental or processing conditions, the time frame required to achieve biodegradation, the degree to which the material was ultimately biodegradable or the quality of the biodegraded residue. Additional information was conveyed by prefixes that indicated the likely breakdown mechanism of the material, including photo (degradation under sunlight), bio (biological organism derived breakdown), hydro (degradation in the presence of water or high moisture content) and oxo (breakdown catalysed by metal salts). There was no plastic that degraded within all-natural or waste treatment environments. When determining if a plastic was biodegradable, it was therefore crucial to have an understanding of where the plastic material would be disposed, i.e. its end-of-life destination. Plastic that was designed to biodegrade was engineered towards a very specific end-of-life destination, for example, landfill, composting or anaerobic digestion treatment processes, and/or the natural environment.

The advertised product was made from polyethylene and a pro-oxidant additive, which made it an oxo-biodegradable plastic. Those plastics, like all plastics, were amenable to biodegradation over timescales that ranged from years to hundreds of years. We understood there was no consensus for what was an acceptable amount of time within which a “biodegradable” product should degrade. We therefore considered that, as a minimum, to be considered a biodegradable plastic product it ought to biodegrade significantly faster than its conventional plastic equivalent in the end-of-life destination that each was likely to find itself. We understood that there was conflicting evidence with regards to the biodegradation in the presence of oxygen of polyethylene that contained a pro-oxidant additive, but that in all instances the samples tested in the evidence we had seen had been exposed to accelerated weathering (a pre-treatment that exposed the sample to enhanced oxidising conditions), and there was also conflicting opinion as to whether the results from such testing methods could be extrapolated directly to real-world environments (i.e. a bag being left in a park or other open space).

More important, it was not disputed that the product would not biodegrade when starved of oxygen, in environments such as landfill. We understood that the most likely destination of bags left in litter bins would be incineration or landfill. That meant that when consumers disposed of the product in a responsible manner, it was no more beneficial for the environment than a conventional plastic dog waste bag. We recognised that not all bags would be disposed of responsibly and that some would be left in various open spaces, with the consequent risk to health and safety arising from dog waste, rather than being placed in a bin. However, because consumers would understand that the ability of the bag to biodegrade meant that by disposing of fouled bags responsibly they would be reducing their impact on the environment, and because the bag was not biodegradable under the conditions which a responsibly disposed-of bag would find itself, we concluded that the claim “These thick waste bags are biodegradable to lessen your dog’s impact on the environment” was misleading.

The ad breached CAP Code (Edition 12) rules 11.3 and 11.7 (Environmental claims).


The ad must not appear again in its current form. We told Ancol Pet Products Ltd to ensure that their future advertising did not mislead by making environmental claims, such as “biodegradable” unless they held adequate evidence to substantiate those claims for the likely conditions of use of the bags.

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