top of page

Meeting High-Level Disinfectant Guidelines in CSSD

Updated: Mar 10, 2022

Prior to the updated ANSI/AAMI ST79:2017 guidelines, air exchange rates in the Central Sterile Processing Departments decontamination room was recommended to be at a minimum of 10 per hour, and the clean workroom had an air exchange recommendation of 4 per hour (ACH). Air exchange rates, or “air changes per hour,” simply refer to the number of times that air gets replaced in each room every hour ( In the case of high-level disinfectants, the ACH rates help reduce vapor intrusion. Today ANSI/AAMI refers users to the ANSI/ASHRAE/ASHE 170 guidelines. The new guidelines recommend a minimum of 6 ACH in the decontamination room while staying consistent with 4 ACH in the clean workroom.

Changes in the guidelines created some disconnects for the HLD process. A number of HLD products recommend a minimum of 10 ACH, while others make recommendations of a minimum of 6 ACH. I tend to find more products that have a recommendation of 10 ACH. This creates an obvious issue if you are performing HLD processes in the decontamination room or the clean workroom. However, the changes also made some improvements with regard to temperature ranges and the use of HLD products. The plus side is that the temperature range increased from the previous ANSI/AAMI recommendation of 60-65F to 60-73F in the decontamination room. This is important because most HLD products list a minimum temperature of 68F for proper use.

Increasing your ACH rates in your workrooms would seem to solve your issue, right? Not so fast, air balancing is critical to reducing cross-contamination in both the decontamination room and the clean workroom, as well as adjoining spaces. By changing your ACH rates you can upset this balance. You need to make sure that your airflow remains positive in your clean workroom and negative in your decontamination room. If you choose to make changes to your ACH rates make sure you use someone who is a professional air balancer to help maintain proper airflow. One solution to help mitigate vapor intrusion is to install freestanding vapor control systems.

To keep the CSSD technicians safe, workspace monitoring is highly recommended. It is the only sure way to understand what level of vapor intrusion you have in your workspaces.

At Evolved Sterile Processing, our consultants have a greater focus on sterile processing. With our decades of experience, we will help you develop better processes and educational resources for your staff.

599 views0 comments

Recent Posts

See All


bottom of page