1. A Survey of Private Sector Respirator Use in the United States: An Overview of Findings
2. National Institute for Occupational Safety and Health . “ Total Inward Leakage Program for Respirators ” . Available at http://www.cdc.gov/niosh/docket/archive/docket036.html (accessed July 10, 2012)
3. National Institute for Occupational Safety and Health . “ Total Inward Leakage Requirements for Half-Mask Air-Purifying Particulate Respirators ” . Available at http://www.cdc.gov/niosh/docket/archive/docket137.html (accessed July 10, 2012)