For September’s Ask the Expert, we talked to Bill Whitford (senior manager of the bioprocess market for Thermo Fisher Scientific) about sourcing animal-free raw materials for cell culture media. This has become a requirement for many biopharmaceutical sponsors, but it is not without its issues. But what precisely is meant by animal is not always clear. Regulatory guidance is sparse on this issue. And a designation of animal-derived–component free (ADCF) often involves additional certification, testing, or auditing. Sponsors and material suppliers struggle with such issues as material handling, cross-contamination, packaging, adhesives, and facility cleaning validation. Questions can remain regarding second- and third-level material and supplier standards. And in attempting to apply a science and risk-based approach to clarifying the ADCF issue, the industry needs to determine precisely what risk the designation is intended to prevent.