waterdroplets thanscrubberbrushes) are necessary. Of course,brushes mustbe
clean beforeuse and be soft enoughnot to damagethe floors.
9.3.3 Performance requirements
It is necessary to have a durable floor adapted to the effective service
characteristics of the foodprocessing area.The mainconstraintsare: mechanical
shocks, heavyweight, pressurejet, chemical agents, thermal shocks, wear,
shifting and rolling.Fallsof heavyobjects, knivesand othersharpobjectsmay
lead to cracks in the floor.Cracksallowwaterto infiltrate underthe floor, which
will progressivelydetachfromthe substrate.A highthickness of the floor is
necessaryto reacha good resistance to mechanical shocksand to thermal
shocks. The smallestacceptable thickness depends of the size of the aggregates.
For a resin-basedfloor,3 mm appears to be a minimumbut a thicknessof 5 mm
is stronglyrecommended. It is of course difficult to knowthe thickness of a
resin-basedfloorwhenthe applicationis finished.Thatis whyit is strongly
recommended to checkwhether the rightquantity of ingredientshas beenused
by countingthe number of bagsused at the end of the application.In the case of
litigation, coreboringsmaybe performedto checkthe minimumand mean
thickness announced. Ceramictile resistanceto thermaland mechanicalshocks
is higherwhen the ratioarea/thickness is small.The thickness of ceramic tiles
adapted for foodprocessing areasranges fromaround 8.5 to 20 mm,but for
industrial premises withhightraffic load a minimumof 12 mm is recommended.
Chemicalconstraintsare essentiallylinkedto the foodprocessed and to the
cleaningand disinfecting productsusedon the flooringmaterials, but also to the
equipment. Sugar, butter, whey and milk products, blood and urine are
substrates for microorganisms presenton flooring materials. Cleaning and
disinfection do not remove or inactivate all microorganisms (Mettler and
Carpentier,1998).Theirmetabolismleadsto the formation of veryaggressive
acid, e.g. lacticacid formedby lactic acid bacteria.Flooring materials also have
to withstandcleaning products suchas alkaline, chlorinated-alkaline and acid
products (whenmineral soil has to be removed) and disinfectants.Peracetic acid
and hydrogen peroxide, frequently used to disinfect equipment, are very
corrosiveand can accidentallyspillon the floor.
9.4 Testmethods.
9.4.1 Slipresistance
`Over 70 machines havebeeninventedto measureslip resistance (Strandberg,
1985),none of themaccurately represents the motion of a human foot and at
present, there is no generally accepted methodof measuring slipperiness'
(Changet al., 2001).The diversityof methodsused at presentleadsto different,
sometimescontradictory,floorclassifications(Tisserandet al., 1995).Thisis
why it is so difficultto select a methodto producea European standard.It is well
178 Handbookof hygiene controlin the foodindustry