MSA Powered Air-Purifying Respirator Cartridge customers should be aware of a potential safety issue regarding OptimAir® TL OV/AG Cartridges (Part Numbers 10080454 for cartridge 6-pack, 10143422 for individual cartridge). Although low in frequency of occurrence in field use and during in-house testing, MSA has become aware of a situation with the spin weld joint between the particulate filter housing and the carbon bed housing of the cartridge. In these cases, the cartridge will continue to provide gas filtration, but may not meet the P100 requirements for particulate and mist filtration. For more information on this issue, click here.