Viruses, Serums, Toxins, and Analogous Products; Standard Requirements for Determination of Residual Free Formaldehyde Content of Biological Products

We are amending the Virus-Serum-Toxin Act regulations for the determination of residual free formaldehyde in veterinary biologics to specify that such determinations be made using the ferric chloride method, and that the residual free formaldehyde content be measured in grams per liter. The ferric chloride method has been adopted as an international standard by scientific experts and regulatory authorities in the United States, Canada, Japan, and the European Union. The effect of this rule will be to reduce the differences in technical requirements for veterinary biologics among regulatory agencies in different countries and further ensure the safety and shelf life of veterinary biologics by adopting a method that has been standardized and accepted internationally.