Disinfectant Efficacy Testing

What is disinfectant efficacy testing (DET)?

Disinfectant efficacy testing (DET) is microbiological testing to ensure aseptic processing areas are consistently maintained, a validated cleaning and disinfection process is required by U.S. and international regulatory authorities. Pharmaceutical, biotechnology, compounding pharmacy, and medical device companies often have controlled environments that require aseptic processing of components and products.

The importance of disinfectant efficacy testing:

The importance of disinfectant efficacy testing is outlined in the establishment of a Current Good Manufacturing Practices (cGMP) compliant process that requires that the disinfectants used are effective and demonstrate the required efficacy within their specific controlled environments.

How to test the effectiveness of disinfectants against microorganisms:

To test the effectiveness of disinfectants against microorganisms, STERIS assists in the design and execution of in vitro efficacy studies, delivering a full report and guidance. This supports the qualification of disinfectants and sporicides used in aseptic processing environments.

At STERIS, we assist Customers with:

Consulting services, including guidance on:
- Study test matrix construction
- Disinfectant contact times
- Procuring a representative surface coupon
- Surfaces and/or organisms to be included in DET study
Development of robust disinfectant efficacy testing protocols
Implementation of real-world procedures for effective use of disinfectants and sporicides
Guidance in the areas of cleaning and disinfection chemistries commonly used in the pharmaceutical and biopharmaceutical industries through our STERIS Life Sciences business

How do you validate disinfectants?

A disinfectant validation is comprised of three parts:

In vitro efficacy testing,
In situ monitoring of the cleanroom environment
Routine environmental monitoring and trending of recovered microorganisms

In vitro efficacy testing:

The purpose of in vitro efficacy testing is to demonstrate that the chosen chemistries/biocides are effective against environmental isolates (bacteria, fungi and spores) on the representative cleanroom surfaces, using test conditions that mimic the standard operating procedures (water quality, presence of organic soil load of concern due to the manufacturing process, use-dilution hold times, exposure time, and exposure temperature).

In situ testing:

In situ field studies demonstrate the ability of disinfectants to reduce and control microorganisms by conducting monitoring of your environment before and after the application of a disinfectant under worst-case conditions of expected microbial levels (e.g., a classified area planned shutdown, construction events, maintenance, etc.). In situ studies generate data that demonstrate the effectiveness of your contamination control strategy, including application method effectiveness.

Environmental monitoring:

Ongoing environmental monitoring provides continual assessment of the effectiveness of your facility’s contamination control strategy. Tracking and trending environmental monitoring data provides assurance that your program remains in a state of control. It can also serve as an indicator that your facility is experiencing shifts in flora that should be evaluated for potential risk to your state of microbial control.

Variables to consider for a disinfectant qualification:

Guidance documents
Organisms: environmental isolates vs. reference strains
Disinfectants/sporicides (Go here for more information on biocides from STERIS Life Sciences)
Exposure temperature
Use dilution hold time
Surfaces (e.g. stainless steel, glass, wall/ceiling materials)
Exposure times
Organic soil load (If applicable)
Water quality (for dilution of test products if appliable)
Timeframe for study completion

Standards:

Below are examples of standards and ISO references that are followed for disinfectant efficacy testing:

International Organization for Standardization. ISO/IEC 13485 Medical Devices- Quality Management Systems- Requirements for Regulatory Purposes
ASTM International. ASTM E2197 Standard Quantitative Disk Carrier Test Method
United States Pharmacopeia. USP <1072> Disinfectants and Antiseptics
United States Pharmacopeia. USP <51> Antimicrobial Effectiveness
United States Pharmacopeia. USP <1227> Validation of Microbial Recovery from Pharmacopeial Articles
European Committee for Standardization. EN 13697 Chemical Disinfectants and Antiseptics

Types of disinfection efficacy testing offered by STERIS:

Testing method following ASTM E2197 Standard Quantitative Disk Carrier Test Method
Testing method following USP <1072> Disinfectants and Antiseptics
Testing method following EN 13697 Chemical Disinfectants and Antiseptics
Use Dilution (Suspension) Testing
USP or EN at controlled conditions (i.e. 2-8 °C and 20-25 °C)