Timber is often treated with combinations of chemicals such as copper-chrome-arsenate (CCA), to increase its durability and pest resistance in certain applications. These chemicals are toxic however, especially if released during processing or incineration after disposal. The recovery options for treated timber are therefore limited. One technology currently used at an industrial scale is the Chartherm™ process in France. This process uses low temperature pyrolysis to produce hydrocarbon gases and a mineral matrix containing the heavy mineral contaminants. The benefit of this system over incineration or combustion is that the temperatures involved are lower than the boiling temperatures of the major contaminants and they are not converted to gases.
There are several emerging technologies for the processing and sorting of treated wood wastes however, most are only in very preliminary stages of development. They include: