WHO Guidelines on Hand Hygiene in Health Care - Safe Care ...

PART I. REVIEW OF SCIENTIFIC DATA RELATED TO HAND HYGIENE
plates. 227 The relative efficacy of plain soap, antimicrobial soaps,
and alcohol-based solutions to reduce the number of bacteria
recovered from hands immediately after use of products for
surgical hand preparation is shown in Table I.11.9. A comparison
of five surgical hand antisepsis products – two alcohol-based
handrubs and three handwashes (active ingredient triclosan,
CHG or povidone-iodine) – by EN 12791, an in vivo laboratory
test, showed that preparations containing povidone-iodine
and triclosan failed the test, although all products passed the
in vitro suspension test of prEN 12054. Better results were
achieved with the alcohol-based handrubs. 464 Alcohol-based
solutions were more effective than washing hands with plain
soap in all studies, and reduced bacterial counts on hands to
a greater extent than antimicrobial soaps or detergents in most
experiments. 268,271,280-286,301,313,316,461-463 Table I.11.10 shows the
log 10
reductions in the release of resident skin flora from clean
hands immediately and 3 hours after use of surgical handrub
products. Alcohol-based preparations proved more efficacious
than plain soap and water, and most formulations were superior
to povidone-iodine- or CHG-containing detergents. Among the
alcohols, a clear positive correlation with their concentration
is noticeable and, when tested at the same concentration, the
range of order in terms of efficacy is: ethanol is less efficacious
than isopropanol, and the latter is less active than n-propanol.
Table I.11.1
Examples of common water contaminants and their effects
Contaminant Examples Concerns
Inorganic salts
Organic matter
• Hardness (dissolved compounds of
calcium and magnesium)
• Heavy metals (metallic elements with
high atomic weights, e.g. iron, chromium,
copper, and lead)
• Trihalomethanes
• Proteins, lipids, polysaccharides
• Inhibit activities of cleaning and biocidal products; can also
cause the build-up of scale over time or “spotting” on a
surface
• Can inhibit the activities of cleaners and biocidal products;
cause damage to some surfaces (e.g. corrosion); in some
cases, are toxic and bioaccumulative
• Toxic chlorine disinfection by-products
• Can leave harmful residues, including protein toxins and
endotoxins (lipopolysaccharide); can also reduce the
effectiveness of biocides
Biocides • Chlorine, bromine • Can cause corrosion and rusting on surfaces (in particular,
when carried in steam)
Microorganisms
• Pseudomonas, Salmonella, and
oocysts of Cryptosporidium
(see Table I.11.2)
• Biofilm formation and biofouling; deposition onto surfaces or
products and cross-contamination
Dissolved gases • CO 2
, Cl 2
and O 2
• Can cause corrosion and rusting (in particular, when carried
in steam); non-condensable gases, such as CO 2
and O 2
, can
inhibit the penetration of steam in sterilization processes
Source: reproduced with permission from McDonnell, 2007. 465
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