Vireo strongly supports the responsible development of alternative testing methods including New Approach Methodologies, NAMS, for safety demonstration, and has collaborated in the past to advance their development and acceptance. But, on review, we found there are significant issues with the findings and conclusions of two reports on the safety of micro and nanofibrillated celluloses recently published as part of a European Food Safety Authority (EFSA) – funded Pilot Project on New Approach Methodologies for the Hazard Assessment of Nanofibers.  Our Short Communication in Trends in Food Science & Technology identifies several issues with the design and reporting of these studies, and raises concern that incorrect interpretations and conclusions were drawn. You can access this paper for free until August 30, 2024 using this special share link. The authors, including Yueyang Zhang, Kimberly J. Ong, James Ede and Jo Anne Shatkin from Vireo Advisors, and represent academic, governmental, and industrial stakeholders with many years of experience working with micro and nanofibrillated celluloses are publishing this paper to provide a critical perspective on the limitations of the reported findings.