I was just reading about this on Fresh Eggs Daily and read that wazine specifically states "do not use on chickens producing eggs for human consumption". The withdrawal period they recommend seems only to be applicable to chickens used for meat. Is this the same for all de-wormer?
http://fresheggsdaily.com/2012/04/pumpkin-soup-nasturtiums-natural.html
Here is a link with more info: http://www.chickenwhisperermagazine...-protect-human-health-and-avoid-drug-residues
Basically most OTC wormers are used off label in chickens because there have been no studies to determine what, if any, effect there is on the eggs, so none are approved for chickens or labeled with withdrawl times. The generally accepted rule is to not use eggs for 14 days after treatment (and I cannot honestly point you to literature where that came from), which is what most people do. I have not personally heard of anyone having a health issue, but that's just me. I also know that some people ignore the withdrawl and continue to eat and use eggs. So, if you have a vet, I would follow their recommendation, if you do not, I would educate yourself as best you can on the medication you decide to use so you are comfortable, whatever you decide. I use Valbazen, Safeguard, and Zimecterin, and following the above recommendations, have not had any issues. Albendazole, the drug in Valbazen, is also used in humans.