You'll need a root cause as to why you weren't handling the air properly to begin with. For a CA, an updated program should include adding the compressor to the PM list (and doing the PM's), some type of filtration for the air at the point of use (filtering at the compressor isn't helpful as the compressor itself contaminates the air), and routine testing of the air at the source to make sure it isn't contaminating the packaging (oils, condensate water, and microbiological as well).
From SQF definitions:
Compressed Air Monitoring: A program that includes particles, water, oil, microbiological, and relevant gaseous testing in compressed air or other gases. A verification of the effectiveness of compressor maintenance and filtration that a management facility has in place.
I'd also make sure compressed air makes its way onto your HACCP plan. You're using the air as a processing aid to do a job, and it has direct affect on final product safety. I'd list it in the flow chart going into the packaging step, then add it to the HA and complete the B/C/P/R categories to make sure you've covered the recognized risks.