Removal of Neonicotinoid Residues from Beeswax Using an Eco-Friendly Oxalic Acid Treatment: A Sustainable Solution for Apicultural Decontamination

Beeswax is widely used in apiculture and can accumulate neonicotinoid residues due to the intensive use of systemic pesticides in agriculture. These contaminants pose potential risks to honeybee health and may indirectly affect the quality and safety of hive products such as honey, pollen, and royal jelly. This study evaluates several decontamination methods for neonicotinoid removal from contaminated beeswax, including modern techniques (microwaves, ultrasonic baths, and magnetic stirring with heating) and conventional approaches based on heat, agitation, and water—either pure or acidified. Among these, the traditional method that uses an aqueous oxalic acid solution proved highly effective, removing over 99% of neonicotinoid residues after two treatment cycles, even at wax quantities up to 200 g. The treatment also improved the colour and physical properties of the wax and was well tolerated by bees, according to a qualitative acceptance test. The simplicity, low cost, and absence of hazardous by-products make this method suitable for scale-up and adoption in real apicultural practices. These findings support the development of accessible and sustainable strategies for the decontamination of wax matrices that may otherwise act as long-term reservoirs of pesticide residues in the food chain.