Residues in Wax
Lexikon
Beeswax stores foreign substances particularly reliably because it is built up from lipophilic, that is fat-loving, molecules.
Beeswax stores foreign substances particularly reliably because it is built up from lipophilic, that is fat-loving, molecules. Substances that dissolve well in fat preferentially accumulate in wax and are barely broken down there over long periods. While honey is usually harvested and removed from the hive within a few months, wax often stays in circulation within a beekeeping operation for many years, so residues can build up in it there.
The focus here is above all on active substances that were themselves used to control the varroa mite, such as older acaricides based on organophosphates or pyrethroids, but also on residues from agriculture that are brought in via pollen and nectar. A study of apiary samples from Spain published in the journal Science of the Total Environment found the substances coumaphos, chlorfenvinphos, fluvalinate and acrinathrin in more than 75 percent of the wax samples examined, as reported by the specialist website bienen-nachrichten.de. For Bavaria, the animal health service reports in its overview of residues in beeswax that, among the samples regularly evaluated, just under half were contaminated to an extent classified as relevant.
Both figures come from different regions, periods and testing approaches and therefore cannot be compared directly, but they consistently show that residues in wax are not a marginal phenomenon, but are regularly detectable in a considerable share of the operations examined. For everyday practice it follows that older combs, which circulate permanently within a beekeeper's own cycle, are potentially more heavily contaminated than young wax.
A common misunderstanding is that residues in wax automatically indicate incorrect or improper use of treatment products. In fact, active substances can accumulate in wax over years even with proper use, because they are barely broken down there. It is therefore recommended to keep an eye on the condition of one's own wax and to regularly replace old combs with fresh wax foundation.