It would be helpful if peak inhalation flow rates were characterized for respiratory design, testing, and use. However, peak flow rates depend strongly on the wearer and the type of work being performed. Instantaneous inhalation rates for subjects exercising on a treadmill have been measured for the following conditions: 1) at 80-85% VO2 max without a respirator, 2) at 80-85% VO2 max while wearing a breath-responsive PAPR (blower flow rate) and 3) at 100% VO2 max without a respirator. Instantaneous inhalation flow rates were found to vary greatly among subjects and at different times for each subject. Depending upon the time that any given flow rate can be sustained, peak flow rates can vary considerably. Instantaneous flow rates were recorded and classified according to 20 L/min ranges so that the flow rate distribution could be obtained. If flow rates in the top one percentile are defined as peak flow rates, then a peak inhalation flow rate of up to 359 L/min (BTPS) was measured for condition 1. Peak instantaneous (less than 1% of flow rates) recorded flows were even higher, up to 442 L/min (BTPS). A peak blower flow rate at up to 679 L/min (BTPS) was measured for condition 2. Flow rates recorded at 100% VO2 Max were generally higher than flow rates 80-85% VO2 max, although this varied somewhat among subjects. A linear relationship has been found between peak flow rate and average minute volume, which can then be used in a procedure to calculate peak flow rates expected at any given work rate.
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.