Ah yes, the caramilk mystery.. Peter: I did a seminar on microencapsulated pesticides a few years ago, and perhaps I could find the information in the archives, but I'm sure you'd get a better answer from one of the manufacturers. Microencapsualted diazinon was (is?) registered in Canada as a Basudin formulation. As I recall, the capsules were a polymer formed as a reaction when a chemical mixed with the pestcide, came in contact with a second chemical as the pesticide was injected into a receiving liquid. By adjusting the injection stream size and pressure, the polymer concentration, and the polar properties of the 2 liquids as the pesticide was injected, droplets of pesticide of the right size, became encapsulated with a wall thickness that resulted in the desired extended release. There were different materials used if the product was water or oil based, but the principle was similar. I don't know if there is a technique for small amounts. Wasn't someone microencapsulating a pollen extract for improving the attractiveness of pollen substitute? Kerry Clark, Apiculture Specialist B.C. Ministry of Agriculture 1201 103 Ave Dawson Creek B.C. V1G 4J2 CANADA Tel (604) 784-2225 fax (604) 784-2299 INTERNET [log in to unmask]