Handbook of Hygiene Control in the Food Industry

equipment.The mainargument in favour of rinsingis the removalof cleaning
chemicalsand possibly reducingthe chancesof developingbiocide resistance,
but this needsto be weighed against the microbiologicalqualityof available
water (at point of use, not entry into the premises), the potential for
recontamination of cleanedsurfaces and the needto preservea dry processing
environment. In the US, a number of sanitisershaveapproved limits for non-
rinse application.If thereare concernsaboutsurfacecountsaftercleaning, the
use of these sanitisers firstat higher levels, followedby rinsing,followedby
theirapplicationat a no rinselevelhas beensuggested (Tompkinet al., 1999).
An alternative is to use a gaseous bactericide, e.g. ozone, as a terminal
disinfectantstage.Thiscan achievean extrakill beforedecomposing to oxygen
(Mooreet al., 2000).The decisionis best left to the individual company,bearing
in mindthe typeand concentrationof cleaningchemicals used,local water
quality, typeof product and the level of risk associatedwithit. It is importantto
realise, however, that the differentstages in cleaning are interlinked and
cumulatively helpto ensurethe overall process is effective. Theycan also
inform how and when monitoringof cleaning needsto be undertaken.

Table36.1 Typicalstagesin a cleaningprogramme

Stage Function Reason

1 Pre-clean Removeloosefoodor dirt,

scrape,vacuum,etc.

Rinsewithwaterto remove

smaller,solublefoodparticles

Improveefficiencyof laterstages,

allowsdetergentaccessto more

firmlyadheringresidues

2 Mainclean Removesmorefirmlyadhering

foodresidue,greaseor dirt.

Usuallydetergentsusedto

emulsifyfoodparticlesand

reducesurfacetension

Improvesefficiencyof laterstages.

Presenceof dirt/residue/grease

reducethe efficacyof disinfectants

3 Rinse Removesdetergentand

emulsified/dissolveddirt and

grease

Improvesefficiencyof disinfection,

minimisesany reactionsbetween

cleaningchemicals.Prevents

microorganismsbeingredeposited

on surfaces

4 Disinfect Furtherreductionin the number

of microorganisms

Minimisesrisk of cross-

contamination,increasesproduct

shelf-lifeand safety

5 Finalrinse Removestracesof disinfectant Minimisesrisk of disinfectant

contaminatingthe food

6 Dry Air dry or use disposable

materialsto minimise

recontamination

Residualmoistureprovidesan

opportunityfor any remaining

microorganismsto growand

surviveand increasethe risk of

cross-contamination(transferrates)

592 Handbookof hygiene controlin the foodindustry