The EN 13624 is the medical phase 2 step 1 test for fungi. There are two different test organisms in the standard. There is the Candida which is the yeast and the Aspergillus which is the mould. The EN 13624 is an obligatory test for disinfectants going into the healthcare market, but you only must have the candida tested. This will then help support a yeasticidal claim. Most surface and instrument disinfectant would also have the Aspergillus tested to give them a fungicidal claim. Although this isn’t stated as a requirement in ECHA certain people will expect this and may only considered disturbing and using a product if it does have a substantiated fungicidal claim. The EN 13624 is very similar to the EN 1650 so usually similar results can be expected on both tests.
The EN 13624 is a suspension test which means it is carried out in a suspension of test organism, interfering substance and test product. The interfering substance and the organism make up 20% of this mix so even ready to use product are diluted to 80% during the testing. If the product is prediluted before the testing starts, we increase the percentage of product by 1.25 to account for the 80% dilution. In the EN 13624 there is a clause that states you can have a modified test that uses a ready to use product at 97% rather than the usual 80%. This is done by concentrating up the inoculum and interfering substance.
As with other suspension tests the EN 13624 can have additional organism tested against it. Some popular organisms that we test against the EN 13624 that aren’t stipulated in the standard are candida aureus and Trichophyton rubrum (the cause of athlete’s foot). Due to the rise of candida aureus infections in healthcare this organism is becoming especially popular to add to medical fungicidal standards.
For BRP submission of a medical disinfectant the EN 13624 against Candida albicans is essential. As for all BPR submissions you must have three concentrations tested. These have to include the final usage concentration, a concentration that fails the test and then any other. Most commonly people opt for the end concentration, 50% of that and the 10% or 1% of that.
The table shows what the standard states as the test parameters but often the NHS will insist on different conditions. This could be 30 second contact time or dirty conditions even when the standards state otherwise. If you are testing for a specific tender, you should check the requirements of this before testing.