At the request of the National Personal Protective Technology Laboratory and the National Center for Immunization and Respiratory Diseases at the Centers for Disease Control and Prevention, The National Academies of Science, Engineering, and Medicine conducted a study on the use of half-facepiece reusable elastomeric respirators in health care. A pdf version of the prepublication copy of that report Reusable Elastomeric Respirators in Health Care:  Considerations for Routine and Surge Use can be downloaded at no cost through the National Academies webpage.