Acaricides in Common Flea and Tick Repellants

Every day, millions of people worldwide engage in a form of pesticide application that they may not be aware of. To keep their pets free of fleas and ticks, many owners of cats and dogs (and perhaps ferrets) use a variety of flea and tick collars containing one or more acaricides, a chemical poisonous or repelling to ticks or mites. While some flea and tick collars use potentially less-toxic repellants, (similar to DEET, which repels but does not kill mosquitoes), most collars use more aggressive chemicals. These collars are designed to release the active-ingredient acaricides over periods as long as several months, so the owners needn’t replace them frequently, resulting in a slow but steady release for long periods. Common acaricides used in collars and topical applications include but are not limited to imidacloprid, fipronil, S-methoprene, and a handful of pyrethroids, sometimes in combination with one another. Since pets have varying degrees of freedom in our dwellings, they may leave traces of these acaricides on our rugs, furniture, clothing, and directly on our bodies. 

Although incomplete, CIL has assembled a database of the ingredients listed for many of the most common flea and tick collars and topical applications. A newer form of administering acaricide-based flea and tick repellants is via pet consumption of active-ingredient chew tabs. We have included the chew tab products in our database as well, though these are less likely to leave acaricide traces indoors. Also included in this database are MSDSs/SDSs when they could be located, but please note that these are subject to change and may have been updated by the manufacturer owing to changes in regulations or product specifications. 

CIL has produced standards used for the analysis of pyrethroid pesticides and their metabolites beginning in the last millennium, and more recently, with concerns about the use of neonicotinoid pesticides and fipronil, has also produced an extensive list of these compounds. At present, isotope-labeled and unlabeled imidacloprid, acetamiprid, thiacloprid, dinotefuran, sulfoxaflor, and propoxur standards are in stock, and isotope-labeled and unlabeled thiamethoxam and clothianidin standards are being developed. Isotope-labeled and unlabeled standards of the metabolites 6-chloronicotinic acid and 3-tetrahydrofuroic acid are also available.