Hundreds of thousands of horseshoe crabs are used for endotoxin testing in the United States each year, bled for their blood’s ability to clot in the presence of toxins. An estimated 10 to 30 percent do not survive the procedure, and the reduced population can also impact other species that feed on the crabs’ eggs. (See AWI Quarterly, winter 2021 and winter 2022).
A nonanimal alternative, the rFC test, exists and has been recognized as a standard method in the European Pharmacopeia since January 2021. However, the US Pharmacopeia (USP), which sets such standards in the United States, has not allowed the use of the rFC test without prohibitive conditions. The USP was expected to allow the rFC test in May of 2020 but changed its mind after pressure from industry.
Now, an expert USP committee has proposed a new standard, Chapter 86, that includes additional techniques for bacterial endotoxin testing that use nonanimal reagents, signaling potential relief for horseshoe crabs. The proposed USP chapter includes information on how to incorporate nonanimal products into endotoxin testing.