“Hey, Marcel! TECOLAB mentioned to me that there is a new standard out for testing surface disinfectants. It’s called EN 17387. Have you heard of it?”—Yes, he’s right, we’ve got a new kid on the block now. But before getting into the new test method, we’d like to revisit the current standard and/or practice that we have been following before the release of the new method. The disinfection process of surface disinfectants relies on the method of application of the product—whether it is applied with or without mechanical wiping action. This includes wiping the surface sprayed with the disinfectant, just spraying it onto the surface to let dry, or fogging it into circulation in an enclosed space. Just like the spell book used by the Sanderson sisters in Hocus Pocus, testing laboratories too have practiced a set of standard tests for surface disinfectants. The table below summarizes the antimicrobial claims available for surface disinfectants according to the current EN 14885:2018.

All the test methods listed in the table above are designed specifically for surface disinfectants used in the medical area except for EN 13697 which evaluates the bactericidal and fungicidal activities of disinfectants used in the food, industrial, domestic, and institutional areas. Since EN 13697 does not specify the test conditions for surface disinfection without mechanical action in the medical area, EN 14885 guideline has outlined the following modification to the test conditions:

1. Temperature: 4 to 30 °C
2. Interfering substance: clean conditions or dirty conditions for medical area
3. Contact time: for surfaces that come in contact with patients or staff and ‘multitouch’ surfaces, not longer than 5 minutes; for other surfaces, not longer than 60 minutes
4. Log reduction: at least 4.00 for bactericidal activity and 3.00 for yeasticidal and fungicidal activity

On August 18, 2021, the European Committee for Standardization (CEN) implemented a new efficacy test method EN 17387 specifically for surface disinfectants intended for use in the medical area. This now allows for a more regulated medical-grade surface disinfectants used without mechanical action in the market.

 

So, What Is The Difference Between EN 13697 And EN 17387?

“Hey, would you look at that—both EN 13697 and EN 17387 have the same steps!”—Both of these tests are carried out by inoculating a stainless steel disc with live bacteria then exposing the surface to the disinfectant before enumerating the surviving bacteria that remains on the surface. These two test methods are very similar in their testing procedure but are still distinct in vital aspects based on how the surface disinfectant is intended to be used. Here, we have mapped out the differences in the test conditions of EN 13697 and EN 17387.

“Wait, why isn’t skimmed milk and yeast extract being used in EN 17387?”—From the table above, the notable difference in test conditions observed between these two test methods are the obligatory test organisms and the interfering substance. These are meticulously designed to reflect the microorganisms and soiling conditions that are present in the respective areas of application as closely as possible. Besides that, the passing criteria that your surface disinfectant has to achieve is also higher when intending to be used in the medical area. This means that your disinfectant shall demonstrate a higher log reduction (or better efficacy), hence making it more difficult to pass when tested with EN 17387.

There are various reasons that contribute to the decision to deem disinfectants used in the medical and healthcare settings to show a higher disinfection efficacy. Individuals in the medical area are more susceptible to contracting diseases or illnesses from a minor presence of dangerous microorganisms in the environment. There is also a higher risk of contact transmission of bacteria between patients and medical staff or visitors. Based on a study assessing the risk of COVID-19 transmission among healthcare workers, it was observed that 2,747 cases were observed out of 100,000 healthcare workers while within the general community, only 242 cases were detected. Besides that, the variety of contaminants present in a healthcare setting is also wider, making the need for disinfectant to have greater efficacy. To answer our bot question, skimmed milk and yeast extracts are not common soiling found in the medical area, thus, are not required to be tested unless with specific instructions given.

Additionally, did you know also that the CEN has also released a separate standard method known as EN 16777 in 2018 for surface disinfectants as well? This standard guides us in evaluating the virucidal activity of surface disinfectants without mechanical action used in the medical area. Based on all the test methods released recently, we have compiled the latest efficacy test methods available for surface disinfectants intended for use in the medical area in the table below.