I know that burning dimensional lumber is not a good thing for stoves or chimneys due to the possibility of chemicals being absorbed during the timbering to milling process - anything from sea salt to blade lubricant to fungicide or dry kilning. However, are wood chips from dimensional and milled wood safe to use for chicken runs or coops (not chick brooders)? Occasionally, the cchickens pick at or even eat some of the shavings, so if I used chips from a woodworker's shop, would this be dangerous? Come to think of it, I wonder what the source of the pine shavings we all use is? If these come from milled wood, then I guess it's the same thing? Thanks.