Determination of known exhalation valve damage using negative pressure user seal-check methods on full-face respirators.
Authors
Delaney L; McKay R
Source
American Industrial Hygiene Conference and Exposition, May 20-25, 2000, Orlando, Florida. Fairfax, VA: American Industrial Hygiene Association, 2000 May; :45
Link
NIOSHTIC No.
20041447
Abstract
Employees wearing respirators in industrial settings rely on users' positive- and negative-pressure seal checks to assess respirator fit. However, few studies have been performed to determine the adequacy of user seal checks in detecting poor-fitting or damaged respirators. In this study, the negative-pressure user seal check (NPUSC) method was evaluated for its ability to adequately detect known exhalation valve damage. The damage included a warped valve, a valve with three slits, and a valve with a small amount of glue. Twenty-six test subjects, wearing full-facepiece respirators, were asked to perform a NPUSC. Their responses as to whether they passed or failed the NPUSC were compared with fit-testing results from two quantitative fit-test methods. In addition, in-mask pressure differentials were measured during the performance of NPUSCs using equipment developed in the UC respirator laboratory. This method was developed as a more reliable technique to assess the ability of respirator wearers to properly conduct user seal checks. The data were analyzed to determine whether the NPUSC procedure is an effective method for detecting known exhalation valve damage. All test subjects reported passing the NPUSC with the undamaged valve. With the respirator equipped with the warped valve, 95% of test subjects reported passing NPUSCs. With the respirator equipped with the valve with adhesive, 65% reported passing. All fit factors were below the OSHA recognized pass/fail criteria, except one test with the respirator equipped with the slit valve. Results from the in-mask pressure measurements confirmed that 98% of all user seal checks were properly conducted. It was unable, however, to detect respirator leakage. In conclusion, NPUSC performed by the user rarely identified damaged exhalation valves.
Links with this icon indicate that you are leaving the CDC website.
The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website.
Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
You will be subject to the destination website's privacy policy when you follow the link.
CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website.
For more information on CDC's web notification policies, see Website Disclaimers.
CDC.gov Privacy Settings
We take your privacy seriously. You can review and change the way we collect information below.
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
Cookies used to make website functionality more relevant to you. These cookies perform functions like remembering presentation options or choices and, in some cases, delivery of web content that based on self-identified area of interests.
Cookies used to track the effectiveness of CDC public health campaigns through clickthrough data.
Cookies used to enable you to share pages and content that you find interesting on CDC.gov through third party social networking and other websites. These cookies may also be used for advertising purposes by these third parties.
Thank you for taking the time to confirm your preferences. If you need to go back and make any changes, you can always do so by going to our Privacy Policy page.