> Formic acid at 54% can be bought in > local hardware shops in 250ml thick plastic bottles with safety tops, > marked 'Kilrock-K kettle descaler'. The Materials Safety Data Sheet > can be downloaded from www.kilrock.co.uk. There is no mention of > anything except the acid. Questions: can such a Materials Data > Sheet, published in conformity with EC Directives, be relied on to > mention contaminants if present? In a word, no. Before I proceed, here are a few URLs of interest for varying reasons: http://shop2.chemassociates.com/shopsite/Chemassoc2/PAS-formicacid.html http://www.fact-index.com/f/fo/formic_acid.html http://www.nsc.org/library/chemical/FormicAc.htm http://www.univarusa.com/assistmsds.htm http://www.univarcanada.com/ Anyhow, what would tell the tale is a Certificate of Analysis, not an MSDS. I've had trouble finding any recent COAs for formic on the web. Anyone got COA URLs for the various grades handy? > Is formic acid available to the > general public in this in other countries? Yes. > Recommendations on > treating hives usually suggest applying 250ml of 65% acid to pads - > would 250ml of 54% work adequately provided the pad size was > increased ratio 65:54, or do we need to complicate the appication by > applying 250 x65/54= 300ml, a bottle and a fifth? Is this what > many beekeepers are doing/have been doing? That is the long term application, much like what NOD is selling. There are other application methods that are more suitable to varying conditions. See http://www.honeybeeworld.com/diary/menus/topics.htm (and choose the mite topics) IMO, 54% would work just fine. The main reason for dilution with water is to control the evaporation rate. At full strength, the formic vapours are too powerful. > In passing, Oust All Purpose Kettle Descaler comes as 3 x 50ml plastic > sachets just in a cardboard carton - packed properly under EC > Directives, so cannot be considered a great safety risk. The Data > Sheet from dylon.co.uk says it consists of 50-70% lactic acid. Lactic acid? > Clearly many think using liquid formic in any way at all is an > unacceptable risk. Kilrock-K has been sold to housewives for 50 > years for them to open the bottle and tip the contents into their > kettles, waering at best household rubber gloves. Why would emptying > it onto a pad in a beehive constitute a greater risk? There is no > comparison with carrying acid in open buckets at a factory. There are risks, but they can be mitigated by following good practices and having an ample (and redundant?) emergency supply of water at hand. allen A Beekeeper's Diary: http://www.honeybeeworld.com/diary/ :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: -- Visit www.honeybeeworld.com/BEE-L for rules, FAQ and other info --- ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::