In 2019, OSHA published a respiratory protection guide for Roofing Contractors, but since I do not work in the construction field I did not pay much attention to it. But today I found some never published guidance from OSHA regarding how an employer can establish a “change-out schedule”. I may have missed this in all the other OSHA/NIOSH documents regarding respirators or my memory may not be what it used to be, but this was new to me and I found it interesting; so I thought you may find it helpful as well. I ALWAYS use computer software to establish my “change-out schedules” and I ALWAYS print the report and make it an Appendix to the written program, but these suggestions were interesting and may explain how some of the schedules are calculated in the software.
For example… did you know that Humidity will reduce the service life of a cartridge by a considerable margin%?
Here is what OSHA said…
As an alternative, OSHA published a guide for estimating times for organic vapor cartridge change-outs. It states the following:
- If a chemical’s boiling point is greater than 158ºF AND the concentration is less than 200 parts per million (ppm), an eight-hour service life at a NORMAL WORKING rate can be expected.
- Service life is inversely proportional to work rate. (This means that as the work rate increases or if it is already high, the length of time the cartridge will remain effective will be less than when work rates and, consequently, breathing rates are lower.)
- Reducing concentrations by a factor of 10 will INCREASE SERVICE LIFE BY A FACTOR OF FIVE.
- Humidity ABOVE 85 percent will REDUCE SERVICE LIFE BY 50 PERCENT.
Cartridge respirators have significant limitations, which can prohibit their use. NIOSH prohibits the use of cartridge respirators when working with some specific chemicals because not all gases and vapors are removed by a cartridge’s medium. The manufacturer should be consulted for final determination of the applicability of cartridge use. Contractors must ensure all filters and cartridges used in the workplace are labeled and color-coded with the NIOSH-approval label, which must remain legible and intact.
Source: https://www.osha.gov/sites/default/files/2019-03/respiratoryprotection.pdf