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Change on the Horizon: USP Chapter 797 Sterile Compounding Changes Series – Part 2

By August 27, 2019C&A Blog

Part 2 of change on the Horizon focuses on the facility design and environmental controls for Sterile Compounding Area (SCA), including microbiological air and surface sampling, cleaning and disinfection of the compounding areas, along with the Certification and Recertification requirements.

Overall, the cleanroom suite should be maintained at a temperature of 20 degrees Celsius or cooler and a relative humidity of below 60% in order to minimize the potential for microbial growth.  Humidity and temperature recordings must be documented daily. If your organization utilizes a continuous recording device, the results of the monitoring must be retrievable.  Free standing air conditioners, heating devices and/or humidifiers are not permitted within the classified area or the perimeter of the SCA.  Devices used to monitor the temperature and humidity must be recalibrated every 12 months or in accordance with the manufacturer’s instructions for the device


There are two different models for placement of the PEC

  • the Clean Room Suite Model
  • the Segregated Compounding Area (SCA) Model

Organizations need to work closely with their facilities management team and architectural resources to select an appropriate location for the SCA as there are many factors that must be considered such as environmental control challenges, and the presence of restrooms, warehouse locations, unsealed windows and doors, which all contribute to the organization’s ability to maintain the appropriate ISO Class and pressure relationships required.  In addition, the PEC must be placed in a location that allows thorough cleaning to occur around the entire PEC.

What is a PEC?

The PEC is the actual created environment or enclosure system in which the sterile compounding process occurs. There are 3 acceptable types of PECs:

  1. Laminar Air Flow System: commonly referred to as the “hood”. These provide an ISO Class 5 or better environment.
  2. Restricted-access Barrier System: is an enclosure that also establishes an ISO Class 5 environment or better. It is designed to allow the entry and exit of products through designated portals, that by design prohibit the transfer of potentially contaminated air into the compounding area.
  3. Pharmaceutical Isolator: a third option that establishes ISO Class 5 air by creating a controlled workspace, the use of specific approved transfer and access devices along with an integral decontamination system. Note: an ante room is not required when using a Pharmaceutical Isolator.

Based upon the type of PEC selected and the environment that the organization creates for the PEC, there are various air exchange requirements that are too detailed for inclusion here.  Please refer to section 4.2 of the July 2019 USP 797 Requirements to obtain details.  Of note, remember that the ISO Class must be measured when the room is at peak operational capacity, meaning when the greatest volume of people and activities is happening.


No matter how many safeguards are built into the physical environment, cleanliness and disinfection of the environment will always be a critical step in keeping patients safe.  The surface of all ceilings, walls, floors, doors, door frames, shelving, work surfaces, fixtures, cabinets and counters must be smooth, impervious and free from cracks and crevices.  This is essential so that they can be cleaned and disinfected.  All junctures between the floor and wall, wall and countertops must be sealed and void of any crevices.  If the ceiling is made of panels, the panels must be caulked in place to seal them.

Remember that anything that is introduced into the clean environment must be constructed of surfaces that meet the above criteria.  This would include chairs, carts, which would include the cleaning of the caster wheels.

Everything must be cleaned prior to disinfection unless an Environmental Protection Agency (EPA) registered (or equivalent) one-step disinfectant cleaner is used which accomplishes both the cleaning and disinfecting processes. A sporicidal agent must also be applied unless your selected product also contains a sporicidal property.  Sterile 70% Isopropyl Alcohol must be applied to each item or surface after each cleaning and disinfection and allowed to air dry to ensure the removal any chemical residue left by the cleaning agent.  Staff assigned to perform the cleaning and disinfection procedures must be trained and appropriately garbed in personal protective equipment. Cleaning must be performed from the clean area to the dirty area.

Under no circumstances, are shipping cartons, uncoated cardboard, or corrugated cardboard permitted inside the classified area or SCA.

Handwashing is an essential component of the compounding process.  Sinks should be designed as hands-free and the sink and sink counter must be cleaned daily with a sporicidal agent applied at least monthly. If your organization is not compounding every day, then the sink must be cleaned prior to its use on the days that compounding is occurring. If your organization is using a clean room, review the July 2019 USP 797 Requirements for specific information regarding sink placement.


Prior to using the equipment and physical environment, the area must be certified to meet the requirements set forth by the Controlled Environment Testing Association (CETA) guidelines or an equivalent guideline.  Make certain that your certification includes certification of the ISO Class 5 areas.  This certification must be renewed every 6 months.  The recertification must include the following components: Airflow testing, HEPA filter integrity testing, total particle count testing and dynamic airflow smoke pattern testing.  The results of each component of the recertification must be made available to the organization and must specifically be reviewed by the USP 797 designated oversight person.  The results of each component must be contained within the recertification report. Should any result be found out-of-range, an immediate plan of correction must be developed, implemented and documented. Retesting must occur to ensure that the actions taken were effective in resolving the concern.


Historically a process that was not widely accepted within the Infection Prevention and Control arena, organizations must establish written procedures for this.  By having an established monitoring program, organizations will be able to review data for trends and identify potential routes of contamination.


The new expectations focus on significant quality control processes that must be in place to ensure the provision of safe services.  Each component of these processes must be documented and signed-off as completed based upon the regulatory prescribed frequency.  We encourage each organization to review the USP 797 Requirements that were released in July to ensure they design a process that captures all new expectations and required documentation.





Patricia Cook

Author Patricia Cook

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