Please clarify on the below Queried.

  1. How many levels of cleaning procedures shall be followed.
  2. Can we consider non clean room equipment in MAC calculation.
  3. What procedure shall we followed for pumping lines cleaning.
  4. What is CEHT and DEHT?

Please clarify on the above questions?


As I am not clear with question #1 and #3, I am answering only question #2 and #4.

In general, products are being produced in control environment, I believe they won’t have any direct contact with non-clean room equipment and products quality is not impacted by non-clean room equipment. Hence, it is justifiable not to consider non-clean room equipment in MAC calculation.

CEHT stands for clean-equipment-hold-time, which is measuring duration to hold equipment after cleaning process and prior to operation; DEHT stands for dirty-equipment-hold-time which is measuring duration to hold soiled equipment prior to cleaning processes. Both elements shall be considered during design of cleaning procedure and shall be included in cleaning validation.


what will be max time limit for CEHT and DEHT. Is it defined in anywhere.

No, I don’t see any standard determines CEHT and DEHT for equipment. The process owner shall determine the holding times. From process point of view, it is normally extended to maximum validated hold time. Therefore, process owner could gather all soiled or used equipment together for cleaning in one cycle. Further, no repeat cleaning is required prior to production usage.