Thanks @Michael_Bush that’s a great link. I’ve got assessment due this Friday so I wont be able to read it before then but there are some interesting results that I’ve skimmed off it already. It’s pretty clear that products used to treat the timber end up in the honey. This is outside my knowledge but I’m guessing that “Naptha (petroleum), hydrotreated heavy” is a fuel oil, in which case that study suggests it “will kill bees unless the treated hive parts are aired for 3-6 months […] Wood impregnated with fuel oil emits odor for a long time.” This is not good news for my hive boxes. I might have to wait until next spring before introducing any bees.
ADDENDUM: I think I should add that my comment is probably a bit alarmist. Many operations use these products to treat beehive timber and we don’t die as a result but it does add to the body burden of unwanted chemicals. Will the bees die if I put them in the boxes I have painted inside and out? I don’t know but possibly not. Certainly, the longer I leave the boxes to air the better. I’m hoping someone who has done the same in the past will be able to let us know the result. Did the bees die? Did the butler do it?