Un-Treating Treated Timber ☠️
How safe is treated timber?
Treated timber used in Australia can come in a few different forms however the typical blue/green tinted soft pine synonymous with construction in the country for the past 30+ years is not as user friendly as most would believe this cheap and plentiful building material to be.
CCA timber or Chromated copper arsenate treated pine is exactly as its name describes; Lumber from a faster growing plantation pine becomes impregnated under high temperatures and pressure with a solution of Chromium, Copper-Oxide and Arsenic. Whilst you may be familiar with the traditional poison of Arsenic, Chromium and Copper-Oxide pose a wide array of health concerns from hematemesis to cancer.
Most pallets (excluding those used in the distribution of fresh food) are treated.
The NSW Environmental Protection Authority has some useful information as to what CCA treated timber can and cannot be used for whilst also citing all the relevant legislative acts that result in in the basics of disposal for unwanted treated timbers, summated from various Acts - CCA treated timber cannot be burned, cannot be recycled and must go into closed cell landfill to prevent land and water table contamination.
But what if the timber could be un-treated?
Science time
Electrodialytic remediation is basically the reverse process of electro plating a conductive material, a common high school science experiment. Whilst a number of smaller scale tests have been conducted around the world for proof of concept in extracting the harmful yet valuable and useful resources from treated timber, at the time of writing no entity is yet to see if the process works on a commercial scale.
The principle is to take treated timber, use a low voltage direct current in a conductive solution to extract the toxic metal compounds and fuse them to a sacrificial anode for additional chemical processing leaving behind essentially clean timber in the precipitate for further recycling into products like manufactured wood flooring and furniture.