90 PRINCIPLES OFFOODSANITATION
ing effect on the hands and is non-irritating.
Also, this process can remove contamination
from gloves and can accomplish hand or
glove washing with approximately 2 L of
water or only one-third of the amount used
in most manual hand washing methods.
Antimicrobial agents exert a continuous
antagonistic action on emerging microbes and
enhance the effectiveness of ordinary hand
soap at the time of application. The overall
efficacy of antimicrobial hand soap depends
on continuous use throughout the day. A con-
tact of less than 5 seconds during hand wash-
ing has little effect on reducing the microbial
load. A cleaning compound will remove more
transient bacteria, with subsequent destruc-
tion by the sanitizer. Contamination from
workers is illustrated in Figure 6–2. Figure
6–3 illustrates the suggested procedures for
use of the recommended double hand wash-
ing method.
A potential barrier to cross-contamina-
tion by the hands is a commercial antibacter-
ial lotion marketed as Bio-Safe. This viscous
lotion forms an invisible and undetectable
polymer coating that bonds electrochemi-
cally to the outermost layer of skin to pro-
vide protection from dermal exposure in the
workplace (Anon., 1997a). Figure 6–4 illus-
trates a wall-mounted hand sanitizer to
reduce microbial contamination of workers.
The use of antiseptic products for hand
cleansing can reduce bacterial load on the
hands and thus decrease the possibility of
cross-contamination. These products include
soap/detergents, instant hand sanitizers, and
antiseptic lotions/creams. Antiseptic soaps
or detergents remove surface bacteria and
may have a residual effect. Instant hand san-
itizers kill bacteria but do not have a residual
effect. The use of protective and antiseptic
lotion products after washing may produce a
residual antibacterial effect, reduce skin
shedding, and protect against the irritating
effects of liquids and latex.
Alcohol hand rub, gel, or rinse sanitizers
that contain at least 60% alcohol have been
incorporated as a disinfection step after
washing hands with soap and water. The
alcohol present will evaporate in approxi-
mately 15 seconds. This hand sanitizer is an
effective sanitizer that improves personal
hygiene and does not contribute to the emer-
gence of microbial resistance. Use of this
hand sanitizer before handling food is gener-
ally considered to be a safe practice. Ethanol
is more effective at destroying viruses than
isopropanol; however, both alcohols are
effective for the destruction of bacteria,
fungi, and viruses. The most effective regi-
men for antimicrobial control is the combi-
nation of an antibacterial soap hand wash
followed by an alcohol gel application (Paul-
son et al., 1999). Caution is necessary when
alcohol is applied because it is flammable at
the concentration found in hand sanitizers.Figure 6–1Mechanized hand washer. (Courtesy
of Meritech Handwashing Systems, Centennial,
Colorado.)