an investigation of domestic laundry in europe - habits ... - SIFO

100An investigation into the domestic laundry habits in Europeindustry and others, some considerations have to be made. Further research isrequired to fine tune the test method itself as well as the sampling method andthe choice of samples in particular.SamplingThe paper shredder is able to cut the samples into small pieces but it is not apractical apparatus. The sharp side has many small parts - which are difficultto disinfect. The risk of contaminating the samples while cutting them is real.When the research objective is to get an indication of the presence of microorganisms,this contamination risk may be acceptable (within limits). Whenthe object is to determine the amount of micro-organisms, the paper shredderis not the best option. The shredder cannot be used to cut items like a sockbecause of the shape. The pieces would not have the same length. That is whythis sample was cut into pieces by hand.The selection of samplesFour different laundry items were chosen for this experiment: a diaper, a dishcloth,a handkerchief and a sock. The diaper and the dishcloth proved to begood samples. They are flat and rectangular pieces of laundry which are easyto cut. The expected bacteria were present in abundant amounts. The handkerchiefis also flat but slightly fragile. Cutting is difficult because the material isa thin layer. The Staphylococcus aureus that were expected were actuallyfound. The micro-organisms that were expected, the yeasts and fungi, werenot found in the socks that were used in these tests. Various micro-organismswere present and some of them disturbed the enumeration of Staphylococcusaureus. This item could be left out of further experiments because it proved tobe an ineffective sample.Is natural contamination a good way to see a hygiene effect?The main problem with natural contamination is that the nature and degree ofcontamination is difficult to control. During this study the amount of microorganismsthat were found prior to conducting the tests was more or less thesame. This means higher levels in the diaper and dishcloth samples and fewermicro-organisms in the sock and handkerchief samples 19 .19 Health regulations state that a reduction of at least log 5 or log 6 is neededfor good disinfection. To find reductions of this magnitude, the unwashedsamples should have a colony count of at least log 6. Only the diaper anddishcloth samples in this study (using naturally soiled laundry) meet thesecriteria for evaluating the Total Plate Count and the Enterobacteriaceae. In allother cases the colony count is so low that an artificial contamination wouldbe needed to investigate the level of disinfection.