U.S. FDA added two ASTM International standards to its List of Recognized Standards. These are E2490: Guide for Measurement of Particle Size Distribution of Nanomaterials in Suspension by Photon Correlation Spectroscopy, and E2535: Guide for Handling Unbound Engineered Nanoscale Particles in Occupational Settings. Guide for Detection and Characterization of Manufactured Silver Nanomaterials in Textiles (WK37636) is in development by ASTM's Nanotechnology Committee (E56).