The ICR-Swab by Merck KGaA, Darmstadt, Germany, allows for swabbing, rinsing and incubating the swab by opening the system only once. Dr Anne-Grit Klees, Global Product Manager Environmental Monitoring, explains

Swabbing is a common method for environmental monitoring in aseptic filling lines for pharmaceuticals. The ICR Swab is designed as a presence-absence test of microorganisms on dry, hard-to-access surfaces in grade A cleanrooms or isolators. The all-in-one design of the ICR Swab minimises the risk of cross-contamination caused by handling.

Residues of disinfectants with different active ingredients may be left behind on dry sanitised surfaces. The risk of microorganism inhibition depends on the concentration of the active ingredients left behind on the surface.

In general, hydrogen peroxide, pure alcohols and oxidative disinfectants do not tend to leave growth inhibiting residues on the dried surface, but stable ingredients such as quaternary ammonium compounds, aldehydes, and phenols will be present even after drying.

The Soybean-Casein Digest Broth (SCDB) within the ICR Swab is supplemented with polysorbate 80 and lecithin acting as an efficient neutraliser against most of the above mentioned stable active ingredients.

Merck KGaA, Darmstadt, Germany has performed several tests to confirm this assumption and to prove the neutralisations efficiency of the growth medium within the ICR Swab. The test results indicate the following conclusions:

Detection of low levels of S. aureus (ATCC 6538 < 30 CFU) in the presence of residues of different disinfectants after growth in SCDB with neutralisers (ICR Swab Medium)

N.B. This article is featured in the June 2019 issue of Cleanroom Technology. The digital edition is available online.