...These practices create an unacceptable risk of beta-lactam cross-contamination in other beta-lactams and in non-beta-lactam APIs.
During the inspection, you stated that you ceased penicillin operations. However, you manufacture other beta-lactam products beyond penicillin, so ceasing penicillin operations is inadequate to address non-penicillin beta-lactams. You should take similar efforts to mitigate the risks of cross-contamination by non-penicillin beta-lactams, because they pose similar risks to patients....
,,,Cleaning cannot substitute for proper segregation. Cross-contamination with your sensitizing agents can initiate life-threatening allergic reactions or other drug-induced hypersensitivity reactions. Your current practices demonstrate an unacceptably high risk of beta-lactam cross-contamination into other APIs packaged at your facility. You should conduct all beta-lactam manufacturing activities in dedicated, segregated facilities with separate air handling systems and production equipment."No safe level" is pretty strong language, even for a FDA warning letter.
No safe level of penicillin contamination has been determined to be a tolerable risk. Severe allergenic response can occur in susceptible patients exposed to extremely low levels of penicillin and other beta-lactams. Such levels are difficult to detect with current analytical methods.