Alternative method for knife disinfection with INSPEXX 200 is more efficient than 82°C water

EU regulations require disinfection of slaughter-equipment with water of at least 82oC. However, according EU regulation 853/2004, an alternative system having an equivalent effect may be used when equivalence can be shown. Ecolab’s Inspexx© 200 (Inspexx) is a solution containing a stabilised blend of peracetic acid, peroctanoic acid and other organic acids – is shown to be an equivalent alternative. It is applied in water at ambient temperatures and does not need to be rinsed after application. A practical trial in a Dutch pork abattoir was performed to study whether Inspexx is adequately effective in disinfecting knives used at slaughter. The standard method of disinfection with water of 82°C is used as reference whereas Enterobacteriaceae and mesophilic aerobic counts are outcome variables. Knives are immersed in hot water or Inspexx for 0, 1, 10, 30 and 60 seconds respectively. Results clearly show that Inspexx reduces bacterial contamination of the knives significantly faster (within 1 second) than hot water, which needs at least 10 seconds. It is therefore concluded that Inspexx 200 can be used more effectively for the disinfection of knives used at slaughter. The outcome of this study confirms a previous efficacy study performed on slaughter equipment. The latter study, in combination with safety and toxicity studies are the basis for official approval of the national authorities of several European countries to apply Inspexx as an alternative method for disinfection of cutting tools during slaughter. In this paper, we show that Inspexx is therewith applicable under practical conditions and a more robust alternative for disinfection of cutting tools used in dressing. Moreover, it can also save water and energy as water needs not to be heated to 82°C. Henceforth, Inspexx does not only improve meat safety, but it will also save environmental resources. Introduction According regulation 853/2004 (EU, 2004) slaughterhouses ‘ [...] must have facilities for disinfecting tools with hot water supplied at not less than 82°C, or an alternative system having an equivalent effect’. The use of water of 82°C can result in the coagulation of protein and melts fats, so that it can disperse over the surface of cutting tools, this can support the forming of biofilms and thus provide salmonella favourable conditions to survive in the slaughter environment. And subsequently, the abattoir has an optimal temperature for salmonella to multiply. Research (Swanenburg et al., 2001) has shown that slaughterhouses can have a house flora of specific salmonella strains. Ecolab developed a product based on the mixture of organic acids with the active substances; peracetic acid (POAA) and peroctanoic acid (POOA). This solution is marketed under the name Inspexx© 200 and is currently used as such in Europe and North America (USA and Canada). In previous studies it is shown that Inspexx can serve as an alternative method for disinfecting slaughter-robots during production. By improving the hygiene of slaughter-robots the microbiological results of carcasses improved as well (Oorburg, Holtslag et al., in prep). Here, we studied whether Inspexx can serve as an alternative disinfection system for knives and whether it provides better microbiological results relative to conventional hot water disinfection. Materials and Methods Before commencing, several application points are identified (e.g. Achilles tendon incision, evisceration). The first part of the study required testing of knives, 2 trials per 3 days. During the first three days the effect of 82°C water is tested, disinfection is performed in the conventional knife sterilisers placed at the respective application points. During the other 3 days disinfection with Inspexx is performed in a knife steriliser located centrally. Knives from 5 different positions in the