platesand subjected to a mildcleaning. The latterconsists of a submersionin a
0.01Msolution of NaOHfollowedby a mechanical action providedby 37
reciprocalmovements of a scouring pad movedoverthe platesurfaceby a
Gardner washabilitymachine (Fig. 9.4). Afterrinsing, residual spores are
detachedby sonication and countedaftergrowth on Shaptonand Hindesagar.
Based on the residual sporescountson the test platesand on platesof the control
material, flooring materials are classifiedas more,as or less cleanable thanthe
control material. Thistest is not intended to accept or reject a flooringmaterial.
Onlythe presenceof crevices,cracksor gas bubble holes, etc., observedundera
stereomicroscopeis considered a criterion to rejecta flooringmaterial.
9.4.3 Materialresistance
European standardised test methods in accordance with the Construction
Products Directive89/106 EEChavebeenproduced by the CENcommittees
Floor screedsandin-situflooringsin buildings'(TC 303)andCeramic tiles'
(TC 67) to assessthe flooringproductsor the system'sperformance.
9.5 Constructionof floors
The recommendationsneeded for the construction of a floorare not provided.
For this subjectsee the sources of furtherinformation below. It can be very
useful to use questionnaires to checkfor all the pointsthat needto be examined
before choosinga flooringmaterial and beforebeginningconstruction. Such
questionnairescan be foundin the French `Guidedes reve√tements de sol' from
Fig. 9.4 The Gardnerwashabilitymachineadaptedto performa cleanabilitytest on 4
2.5 cm^2 test plates.
180 Handbookof hygiene controlin the foodindustry