There are certainly a number of suitable commercial masks available. As I stated in a prior posting, the FEMA/USPHS team that I deployed to New York with uses an MSA PAPR with commercially available filters. <br><br>Similar to SCUBA equipment and most anything, people have strong opinions as to what is "best" while many things are suitable for use.<br><br>In the case of bio-terrorism, a simple respirator with a mechanical filter is acceptable, as agents are spread through inhalation or ingestion. To the best of my knowledge, there are no bio agents that are able to pass through intact skin.<br><br>Anthrax is spread in two ways: inhalation, which results in a far more lethal pulmonary infection and through open wounds which is not as serious and rarely life threatening. Anthrax pneumonia is not contagious.<br><br>Other, particularly viral, agents are far more serious, as they are contagious. In our era of global travel, it is very unlikely that use of a viral pathogen would result in casualties in only one geographic region and could spread world-wide.<br><br>Simply wearing a mask does not offer protection against either chemical or biological hazards. Tyvek and other similar suits with hoods and booties, nitrile gloves, and 10% bleach are also important.<br><br>Jeffery S. Anderson, M.D.<br><br>