Hi Mark,
Last year Sulphadiazine (same group as Sulfathiazole) was detected in our honey at a concentration of 32PPB.  We never used any drugs from the Sulphanomide group in our beekeeping operation.  This resulted in us having to withdraw our honey from the market and we will go to court about it, with a possible jail sentence.  The amount detected was very low and not a danger to public health, but the law saws no antibiotics residues anymore and the LOD is 10PPB.  Usually antibiotics break down with light, heat and time, but unfortunately this group of antibiotics has the characteristic of combining with the honey molecule and becomes very stable and can be present in honey years after use.  The other possibilty is that some herbicides, Asulam is one of them, can enter the hive on bees and these then break down into chemicals that are in the Sulphanomide group.   The only solution is to completely change all the combs and start again.
Best regards
Roger White
Superbee bees Cyprus.

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