I know that there are firms in Europe testing and certifying foundation wax as pesticide-free.  Whether this is truly necessary or clever marketing is a different question.
In the USA, Rogers Simmonds at the USDA NSL analytical laboratory in Gastonia, told me years ago, that he found was detected pesticides in samples of wax and waxed foundation sheets.
The answer is this - if you are concerned about pesticide residues in foundation, sacrifice a couple, send to Roger for analysis.  Call the lab before sending for instructions.  There is a fee, so it's might be a good project for your local bee club, rather than for an individual with one or two colonies.
When in doubt, have it tested.  Your bees deserve it, just as you'd take your cat or dog to the vet.  If you are 'organic', put it to the test so that you can tell your customers that you've had your wax tested.
Jerry

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html