Controlled Environment Certification: CETA Guidelines Update

May 2012 - Vol.9 No. 5 - Page #30

Q&A with James T. Wagner, Principal
Controlled Environment Consulting


Pharmacy Purchasing & Products: What was the impetus for the January 2012 updating of the CETA guidelines?
Wagner: The Controlled Environment Testing Association (CETA) guidelines have changed over time to maintain consistency with USP General Chapter <797> and with current trends in certification. In addition, when CETA finalized the certifier accreditation program in 2011, it became clear that further guidance was needed in some areas. For example, references have been added to every test question (see CETA’s Professional Certifier Program sidebar); in the previous version of the guidelines, some questions contained no references. Providing references is  important to ensure every facility has access to the same industry information and that every certifier will judge compliance based on the same data. Material has been added to provide guidance where it might have been previously lacking. In some cases, we simply added common practice items to the guidelines; many of these were considered general knowledge and consequently were not included in the first iteration of the guidelines. However, upon review of the certifier accreditation tests, it became evident that guidance was required, especially when selecting between two accepted practices. When different approaches result in different answers, those variances become significant on a written test. 

For example, the new guidelines clarify how to calculate the effective area of a HEPA filter. Previously, using sound logic, certifiers could apply different paradigms that would result in slightly different numbers. By specifying a single acceptable method in the guideline, we were able to eliminate any confusion, establish one correct answer for the test, and ensure more consistent field testing among certification companies. 

PP&P: What else is new within the CETA guidelines?
Wagner: CETA has made multiple updates within the past year. Changes have been made to the Certification Matrix for Sterile Compounding Facilities – Secondary Engineering Controls (CAG-008) and Informational Notes to Meet the NSF/ANSI 49:2010a Standard Requirements for Class II BSC (CAG-010). In addition, one new applications guide was added; USP <797> Viable Environmental Sampling and Gowning Evaluation (CAG-009) provides additional guidance for environmental monitoring for USP <797> compliance. 

Updates have also been made to the Certification Guide for Sterile Compounding Facilities (CAG-003). One alteration is the addition of guidance information for air change rates. Chapter <797> offers no guidance for acceptable air exchange rates in an ISO Class 8 ante area, it only recommends air change values for ISO Class 7 rooms. Based on the FDA aseptic processing guide, CETA CAG-003 now recommends a minimum of 20 air changes per hour (ACPH) for ISO Class 8 ante areas. Although this is only a recommendation, it has proven helpful as many pharmacists are looking for a simple starting point. However, it is important to remember that air change rates—whether stated in USP or by CETA—are only a general foundation and may vary; the amount of activity in a room, the number of personnel, and other potential particle generators may result in the need for more than the minimum air exchange rate to maintain ISO classification (see Determining the Appropriate Number of Air Changes per Hour sidebar). 

Most specific test procedures in CAG-003 reference industry literature. General guidance for leak testing HEPA filters has been provided in many different industry standards and guidance documents. Upon additional review, it was determined that language in the industry reference introduced unnecessary ambiguity and resulted in no added benefit. Therefore, changes were made to ensure CAG-003 is precise and consistent with what occurs in the field. For example, CAG-003 now provides exact probe size and scan speeds for leak testing HEPA filters in cleanrooms and laminar air flow workstations (LAFWs). 

The previous iteration of the CETA guidelines directed users to follow ISO 14644-1 for guidance in conducting nonviable particle counting, but no specifics were included. Because the ISO documents are international and cross various industries, they are nonspecific by design. Therefore, CAG-003 has been updated to provide explicit methods and minimum sample volumes appropriate for sterile compounding facilities to ensure compliance with USP <797>. 

CAG-003 now provides specific guidance for velocity measurement locations for LAFWs in sterile compounding facilities. The general guidance found in the industry reference allows for a range of velocity measurement locations. We narrowed our recommendation within the general industry guidance to result in more consistent testing. 

PP&P: How will these changes affect the way hospital pharmacy cleanrooms are certified?
Wagner: Most certifiers are aware of the CETA guides’ status as the referenced certification procedures in USP chapter <797>. Nonetheless, it is common to find inadequate testing, and all too frequently, no reference to CAG-003 within certification reports. Our goal is to ensure that the CETA National Board of Testing (CNBT) certifier accreditation program, which is based on these applications guides, has an impact on use of CAG-003 and increases appropriate testing practices. 

All pharmacy directors should insist that their certifier be CNBT-accredited, and all sterile compounding facilities built to comply with USP Chapter <797> should be certified to CAG-003. The changes to the applications guides will facilitate the accreditation program, which will expedite the overdue improvement to the certification process. 

PP&P: What are the most important updates for pharmacy directors to be aware of? 
Wagner: Pharmacy directors should recognize that there are specific certification procedures recommended in USP Chapter <797> and that an accreditation program exists for certifiers. At a minimum, the pharmacy director should ensure that a CNBT-accredited certifier certify the facility to CAG-003. If their current certifier is not CNBT-accredited, pharmacy directors should require that they gain accreditation. 

Pharmacy directors also should be aware that CAG-008 is designed to be used by the pharmacist to review their certification report. It includes a matrix of test criteria and documentation points to compare against their certifier’s report. The points of interest include ensuring airflow in both hazardous and nonhazardous compounding rooms, room segregation for both hazardous and nonhazardous compounding rooms, HEPA filter integrity testing, airflow smoke pattern testing, particle count survey requirements, and temperature and humidity recommendations. 

Keeping abreast of controlled environment certification updates and using a CNBT-accredited certifier are key to ensure sterile compounding facilities are in compliance with USP Chapter <797>. 

James T. Wagner, principal of Controlled Environment Consulting, has over 30 years’ experience designing and evaluating facilities used for aseptic processing. He was a member of the 2005-2010 USP Sterile Compounding Committee responsible for USP Chapter <797>. 























CETA’s Professional Certifier Program
CETA’s certification program for individuals who certify hospital pharmacy cleanrooms, isolators, and other engineering controls is designed to ensure certifiers possess baseline qualifications, allowing hospital pharmacists to identify qualified certifiers with confidence and ease. The program was designed specifically for the certification professional specializing in sterile compounding facilities.



The program includes both a written and a practical test, and was developed in accordance with ISO/IEC 17024 Accreditation Standards for Personnel Certification as administered by the American National Standards Institute. The written test questions were based on the following criteria:

  • Understanding the facility requirements
  • Counting total particles (determining cleanliness class)
  • Performing environmental monitoring
  • Determining air exchange rates
  • Testing airflow velocities
  • Proving room segregation
  • Testing HEPA filters
  • Performing airflow visualization
  • Preparing certification reports

The practical test demonstrates how the certifier applies the fundamentals displayed in the written test in real life situations. Examples of practical test challenges include the demonstrated knowledge of, and ability to use, all required equipment in actual field conditions.
Registered cleanroom certification professionals for sterile compounding facilities can be found on the CETA Website,
To read PP&P’s October, 2010 article on CETA’s Professional Certifier Program, go to .























Determining the Appropriate Number of Air Changes per Hour
Room air exchange rates are typically determined by measuring the supply air to a positive pressure room and the exhaust air from a negative pressure room. However, for compliance with USP Chapter <797>, the HEPA-filtered supply air exchange rate is the only concern. Therefore, air exchange rates for all buffer and ante rooms are based on the comparison of HEPA-filtered supply air (in cubic feet per minute [CFM]) to the room volume (length x width x ceiling height in cubic feet - FT3). 



CFM ÷ FT3 = Air Changes Per Minute (ACPM) x 60 = Air Changes Per Hour (ACPH)

The minimum air exchange rate of 30 ACPH referenced in Chapter <797> is based on normal compounding environments. Each application should be evaluated based on potential process-generated contamination, number of personnel, and other potential particle generators, such as refrigerators and printers. Keep in mind that the effect of particle generators can be offset by laminar air flow workstations (LAFWs) that are vented back into the room. 

Positive pressure buffer rooms typically perform adequately near the minimum recommended 30 ACPH because of the recirculated HEPA-filtered air from the LAFWs. The LAFWs often contribute more HEPA-filtered air to the room than the HVAC system, so the actual air exchange rate is significantly more than the USP mandated minimum. 

Conversely, negative pressure hazardous drug compounding rooms employ externally vented primary engineering controls (as opposed to LAFWs which recirculate back into the room), so the HVAC-supplied air is the only HEPA-filtered air supplied to the room. In addition, the negative pressure room will pull in unfiltered air through cracks and crevices. Therefore, negative pressure ISO Class 7 rooms are often designed for 60 or more ACPH from the HVAC system. Remember, the goal is to dilute the particulate contamination in a room with particulate-free, HEPA-filtered air. The more potential for contamination, the higher the required HEPA-filtered air exchange rate.







Contact Information for CETA International
1500 Sunday Drive, Suite 102, 
Raleigh, NC 27607
Phone: 919-861-5576Fax: 919-787-4916



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