exercisedif nets are installed.Somebirds havebeenfoundto pecklargerholes
in the netting, so gainingaccess to the protectedarea where they are trappedand
die.This practice,in turn,presentsa potentialcontaminationproblem and
should be avoidedin favorof eitherremovingthe overhangor changingit to one
witha smoothunderside.
Rail docksshouldbe wideenoughto allowforklift trucksto loadand turn as
theybackout of the rail cars.Bracing and otherdunnageshouldnot be stacked
against the walls. Rodentscan easily buildnestsbehindthe materials if they
remain more than24 hours. Raildocksshouldnot be usedas storagefor extra
equipment,product or wastematerials. Interior rail docksshouldbe equipped
withan overhead doorthat can be closedwhilethe rail car is being loaded or
unloaded.Thespacebesidethe railsunderthe doorshouldbe fittedwitha
compressible rubberplugto keeprodentsout of the area whenthe dooris closed.
The plugwill compresswhenthe rail car flangepassedover it and thenresume
its shapeafterthe wheel has passedover. Whenthe overheaddooris closed,the
expanded plugwillfill the void.Theseare available fromrailroad supply
houses.
7.8 Entry/exit pointsand externallighting
Personnelentryand exit doorshavethe potentialto becomeentrydoorsfor
rodents. Thesedoorsshould havea tightfit witha gap of less than0.25inches
(6 mm) at the bottom.Personnel doorsshould not openinto the processingareas
but into a hallway or directlyinto the personnelfacilitiesareasuchas locker
rooms. Thepreferredmaterialfor personneldoors is metalwith expanded
urethane-filledcores.Air curtainsshould be installedoverall personnelentry
and exit doorsto preventinsect entrywhen opened.
7.8.1 Dockdoors
Vertical lift dockdoorsare preferredfor goodsanitary design.If the vertical
height for verticallift is not available then the overhead garagedoortype can be
used.Thethirdchoice is a roll-uptypedoorwith no housing.Roll-up door
housings havebeenobservedharboring insects. Existing roll-updoor housing
has beencut and hingesinstalled so it can be openedand cleanedon a routine
basis.
7.8.2 External lighting
Dock doorsshouldnot havelightspositionedaboveor beside them.Lightscan
be insectattractants, especially those that emit highlevels of ultraviolet.
Ultraviolet raysare attractive to flyinginsects; thusthe successof insect
electrocutors. If possible, lightsshouldbe positionedon standards about30 feet
(9 m) awayand shinebackon to the doors. High-pressure sodium lightsare
132 Handbookof hygiene controlin the foodindustry