In a message dated 14/02/2009 16:20:50 GMT Standard Time, [log in to unmask] writes: Low pH, plus heat, in an iron tank leads to rapid HMF formation, and can cause bee toxicity. How toxic to bees is HMF? They must have been exposed to it in low doses for ever. Chris ******************************************************* * Search the BEE-L archives at: * * http://listserv.albany.edu:8080/cgi-bin/wa?S1=bee-l * *******************************************************