Oxalic acid is extremely effective for the control of Varroa in brood free bee colonies. When applied properly, the three forms of application, spraying, trickling and vaporizing, have an efficacy of more than 95 %. A three-year study showed that the natural content of oxalic acid in spring honey is not increased. Thus, no residue problems are to be expected. The three treatments have shown a good bee tolerability and thus do not significantly differ in this respect from the untreated control.

The examination of Gympp and his staff from the Institute for Occupational- and Social Medicine of the University of Tübingen has shown that the health of the beekeepers is not endangered during spraying and vaporizing if the recommended protective measures are followed.

Oxalic acid solutions in sugar syrup can be stored for longer periods of time only when the storage temperature is lower than 5°C. Otherwise, the oxalic acid has to be prepared shortly before use.