I agree, in a lab setting , disinfectants and sanitizers are very effective against microbes when their toxic levels (dose) could be maintained and delivered. That's a big leap to the real world where the products are used and unfortunately this doesn't always happen in the field and some sanitizers for food contact surfaces provide sub-lethal levels of the residual active ingredients for toxicity reasons whereby the microbes have been shown to adapt. Just look at all the evidence of pseudomonas spp. pumping out QAC's. Also failure to maintain the required contact time set's up conditions for adaptation. Sanitizer test methods claiming 99.9% kill are also NOT representative of real world efficacy because they are tested in solution instead of a real surface or with ASTM 2197. I would give them 30% efficacy in the real world at most and that's equivalent to much less than 1 log.

How do you make sure you don't contaminate the sterile coupons during the testing process. If you need to lie the coupon flat to apply the target organism on the top how do you keep the bottom sterile so if you are immersing the coupon fully you don't get contamination. How do you achieve that? Thanks