Principles of Food Sanitation

(ff) #1
they are permitted to handle food prod-
ucts.
●Intestinal microorganisms. This group of
organisms includes Salmonella, Shigella,
Escherichia coli, Cholera, infectious hep-
atitis, and infectious intestinal amoebas.
These microorganisms are of public
health concern because they can con-
tribute to serious illness.

Hand Washing


Microorganisms found on the hand sur-
faces may be transient bacteria or resident
bacteria. Transient bacteria are picked up
accidentally by food handlers and are tran-
sient in that they reside on the hands only
temporarily (e.g.,E. coli). Residual microor-
ganisms permanently reside on the hand sur-
faces and are the normal or resident
microflora of the skin (e.g.,Staphylococcus
epidermidis).
The first line of defense against disease is
frequent and effective hand washing by food
handlers (Taylor, 2000). Approximately 38%
of food contamination is attributable to
improper hand washing. The most effective
method to ensure effective hand washing is
through motivation, reinforcement, incen-
tives, and modeling through supervisors and
managers practicing appropriate hand wash-
ing. Hand washing is conducted to break the
transmission route of the microorganisms
from the hands to another source and to
reduce resident bacteria. Pseudomonas
aeruginosa,Klebsiella pneumoniae,Serratia
marcescens,E. coli, and S. aureuscan survive
for up to 90 minutes when artificially inocu-
lated on the fingertips (Filho et al., 1985).
Hand washing for 15 seconds (as opposed
to the average of 7 seconds) with soap and
water, which act as emulsifying agents to solu-
bilize grease and oils on the hands, will remove
transient bacteria. Increased friction through
rubbing the hands together or by using a scrub
brush with soap can reduce the number of


transient and resident bacteria than is done by
quick hand washing. Hand washing and dry-
ing efficacy against resident flora ranges from
35 to 60%. All hand washing agents, including
water, are effective when the hands are dried
with paper towels. Alcohol-based instant hand
sanitizers used after hand washing, provide an
additional 10- to 100-fold reduction (Anon.,
2002). Instant hand sanitizers (protective
creams and lotions) should be considered
when washing is not possible but they do not
have a lasting effect (Taylor, 2000). The key
facets to improved hand washing are motiva-
tion and training. Although a certain amount
of education is essential, a multidisciplinary
framework should target institutional or orga-
nizational change. Training should be risk-
based with the consequences of improper
hand washing clearly expressed.
Because proper hand washing is essential
to attain a sanitary operation, mechanized
hand washers are being used (Figure 6–1). A
typical unit is located in the processing area.
When workers enter the area, they must use
the washing unit. This equipment is respon-
sible for increased hand washing frequency
by 300%. The user inserts the hands into two
cylinders, passing a photo-optic sensor,
which activates the cleansing action. High-
pressure jet sprays within each cylinder spray
a mixture of antimicrobial cleansing solu-
tion and water on the hands, followed by a
potable water rinse. The 10-second (pro-
grammable from 10 to 20 seconds), massage-
like cycle has been clinically proven to be
60% more effective at removing pathogenic
bacteria from the hands than the average
manual hand washing (Anon., 1997b) and
reduced water costs. The high-pressure, low-
volume spray uses approximately 2 L of
water per wash cycle, one-third of the
amount spent in most manual hand washing
methods. Up to a 300% increase in washing
frequency is accomplished because this
equipment provides an easy-to-use, massag-

Personal Hygiene and Sanitary Food Handling 89
Free download pdf