[....]As Howard said here above, "...all finishes manufactured in the US since the mid 1970's are non-toxic once fully dried or cured." This is true, but obtaining 'fully dried or cured' is the challenge. This book, by Bob Flexner is da BOMB. It has changed my attitudes about natural vs synthetic wood finishes. I'm not as hostile to synthetics as I was before. But VOCs remain a concern. From the Wiki entry VOCs, it appears that they are a significant health hazard. Off-gassing has a half-life, so in theory, it is never completely done. But, assuming that the levels get extremely low, it appears that at least some products are so safe that the gov't allows them to be used in situations where children could actually chew on wood that has been treated with them. Flexner has a strong opinion about this and thinks that using 'food safe' as a criterion for selecting a product is a waste of time.
-[...]felling a conifer [...] puts more turpentine into the air than most of us do in a lifetime of amateur wood finishing.
[...]-Alcohols like used for shellac are part of normal biochemical processes even in our bodies and should not be grouped with the hydrocarbons like varsol or paraffin wax.
-Bleached/blond shellac is probably the least colouring finish with almost no VOCs. Wax is not a finish with significant protection of the wood . It does add a bit of luster to the finish and reduces friction.
thanks for your post. it's nice to get back on topic. and i also appreciate the opportunity for reasoned, evidence-based discussion.
as i said, my opinion is evolving regarding the use of products that contain VOCs. the flexner book was fairly convincing, overall. but i'm still a bit wary. i'm not so much concerned about VOCs polluting THE air as i am concerned about VOCs polluting MY air. my girlfriend is pretty sensitive to chemical odors, and i have a friend who can't handle any off-gassing from plywood and the like--he had to retire early after working in a 'sick building' for several years.
since VOCs have a half-life, a product never stops emitting VOCs. but, at some point, the emissions get so small that they are no longer an issue. the question is WHEN, and that depends on a lot of factors--product type, temperature, humidity, physiological sensitivity. i'm probably going to buy a bed made with untreated wood and finish it myself. are we going to sleep in that bed with VOCs coming out, however mild the odor? i don't think so.
yes, shellac is an attractive product b/c it's dissolved in alcohol, which seems to be fairly harmless and evaporates quickly. the problem with shellac, apparently, is that it doesn't cover pine knots, and this bed will be pine...
yes, wax, is not a great solution b/c, as flexner points out, it doesn't protect much against scratches, and it has to be re-applied regularly.
linseed and tung oil last longer but also do not protect against scratches, nor against liquid stains. but tung oil may be the best solution for the aforementioned bed b/c i'm not worried so much about scratches or stains; the main concern is smudges and dirt.