Hello,
I am new here and I am also relatively new to the QA field (~1year). I work for a CBD/Hemp manufacturing company and I am looking for clarity regarding our compressed air results I have received (see below). The method our lab uses is the "impinger" method where they run the compressed air through water for 15 minutes. We implemented a new compressed air line in April and after the addition of the filters we see that it improved to below the lab's LOQ after our re test in April. In December we tested again and showed issues with the 0.5 micron filter. We decided to replace the filter with a 0.1 micron filter and somehow still received a count for yeast and mold. My question comes down to why did I get two counts of Y&M after the 0.1 micron filter installation when it showed below LOQ on the last test for the 0.5 micron filter. Additionally, due to having little data for this new line, i have no established limits and am wondering if a count of 2 for Y&M is acceptable or if I should be striving for non-detect. This compressed air blows directly on a food contact surface. Any help would be superb, thanks so much!
April 2023 (No Filter): APC = 2 CFU/10ft3
Y&M = 4 CFU/10ft3
April 2023 (0.5 micron filter): APC = <2 CFU/10ft3
Y&M = <2 CFU/10ft3
December 2023 (0.5 micron filter): APC = 36 CFU/10ft3
Y&M = 2 CFU/10ft3
December 2023 (0.5 micron filter): APC = 98 CFU/10ft3
Y&M = <2 CFU/10ft3
December 2023 (0.5 micron filter): APC = <2 CFU/10ft3
Y&M = <2 CFU/10ft3
January 2024 (0.1 micron filter): APC = <2 CFU/10ft3
Y&M = 2 CFU/10ft3