Powder Coat Disposal

In the second article of this two part series Steve Kelly, Operations Manager of Akzo Nobel, discusses the safe disposal of Powder Coat Waste following the presentation given to Qualicoat members at their quarterly meeting in Gateshead.

Over the last five years, disposal of all ‘waste’ materials has been tightened up considerably, the emphasis is now on increased re-cycling and reducing waste disposal in landfill sites. As a result, costs for using landfill sites are increasing rapidly which can in turn make recycling a viable proposition. The majority of waste powder is taken to landfill sites as other forms of disposal, such as incineration are still too expensive. There is no current option to re-use the waste polyester as no such re-cycling option exists, however, as costs continue to rise a re-cycling option in the future will no doubt be found.

Waste polyester powder in its original form before application or after stripping and removal of the stripping solvents, is not deemed to be 'Hazardous Waste', according to the Environment Agency, and falls within the 'Controlled Waste' classification. The definition of 'Controlled waste' in UK legislation is: ‘Any substance that constitutes a scrap material or an effluent or other unwanted substance arising from any process’ or ‘Any substance or article which requires to be disposed of as being broken, worn out, contaminated or otherwise spoiled’ (EPA 1990).

In disposal there is a 'Duty of Care' responsibility which ensures that the producer of the waste has a legal duty to take all reasonable steps to ensure that their wastes are managed and disposed of without harm to the environment. The requirements include; storing waste safely and securely, only transferring waste to authorised persons (registered waste carriers) and that the waste must be described in writing at the time of the transfer in the form of 'transfer notes. Even though waste has been passed to third parties there is still a responsibility of the producer to ensure the waste is properly disposed. It is quite normal for waste to be followed by a representative of the producer all the way to its disposal location in order to show this 'Duty of Care'.

Transfer notes must be kept for 2 years, but for repeated waste movements, same material and disposal site, one transfer note can be used for up to one year. Transfer notes must now include a European Waste Catalogue (EWC) code. The Environment Agency has made a decision that all powder waste should be identified by the following EWC code: '08 02 01 – Waste Coating powders'.

'Hazardous waste', was termed as 'Special waste' until recently and is only deemed hazardous if dangerous substances are present above threshold concentrations. In general the more hazardous the substance the lower the threshold of content in classification of the waste as hazardous. Fourteen hazard properties exist, these are: H1 - Explosive, H2 - Oxidising, H3 - Flammable, H4 - Irritant, H5 - Harmful, H6 - Toxic, H7 - Carcinogenic, H8 - Corrosive, H9 - Infectious, H10 - Toxic for reproduction, H11 - Mutagenic, H12 - Produces toxic gases in contact with water, air or acid, H13 - Can produce another hazardous substance after disposal and H14 - Ecotoxicity.

Elimination of triglycidylisocyanurate and lead by most suppliers has led to the vast majority of Powder Coatings being classified as non-hazardous. The threshold levels for content of Triglycidylisocyanurate and Lead are very low and in essence if either of these substances are present then the waste is deemed to be 'Hazardous'. Some powders may contain other substances classed as irritants, harmful, dangerous to the environment, whilst 'Hazardous waste' thresholds are higher there will be a requirement for the user to seek information from the supplier. Material Safety Data Sheets supplied by the powder manufacturer, provides information to correctly classify the waste powder.

The Environment Agency has the final say on classification of waste and there are many documents available to ensure producers of waste are clearly informed of their responsibility. Its also important to be aware that each landfill site may take other issues into consideration such as how easy is the material to handle? At one time waste sites were allowed to take all forms of waste, now 'Hazardous waste' can only be disposed of at a dedicated hazardous waste site. Landfill sites can no longer dispose of 'Hazardous waste' alongside 'Non-Hazardous waste'.

As well complying with the Duty of Care requirements the waste producer must register as a 'Hazardous waste' producer and complete a consignment note for the transfer of hazardous waste. Remember that these notes generally must be kept for a minimum of three years.

Whilst the conditions apply to polyester powder disposal, they will equally apply to other materials such as PVCu and possibly older coated fenestration products which may contain trace elements of triglycidylisocyanurate and lead. One thing for certain is that disposing of our waste products from manufacture and/or removed products is set to become much more expensive in the future. The industry needs to develop new ways to reuse and reduce wastage.