Cleaning and Disinfection:
Chemical Disinfectants Explained
This briefing material has been produced for those who work in healthcare
professions, the media and others who are looking for some background
understanding of chemical disinfectants (including antibacterial products which are
used in the home and/or those who are responsible for providing guidance to the
public on understanding these issues.
Hygiene in the home
Home Hygiene means the prevention of spread of pathogens in the home to stop
family members from becoming infected. Pathogens are introduced continually into
the home, by people (who may have an infection, or who may be asymptomatic), by
contaminated food and domestic animals, and also sometimes in water, or via the air.
Additionally, sites where stagnant water accumulate such as sinks, toilets, baths,
tiled surfaces, waste pipes, or cleaning and face cloths readily support microbial
growth and can become a reservoir of infection; although, in this case, species are
mostly those which represent a risk only to vulnerable groups.
Within the home, there is a chain of events (see Fig. 1) that results in spread of
infection from these sources to a new recipient. Limiting the exit and entry of
pathogens from or into the human body involves activities such as good respiratory
hygiene, care of wounds, etc. Thorough cooking and safe storage of food and
household water treatment and safe storage are also part of home hygiene. In
communities where public water supplies are unsafe and/or inadequate, provision of
safe water for the family through “household water treatment and safe storage” is
also part of home hygiene.
The approach that IFH has adopted to breaking the “spread of infection” link in the
home is known as “targeted hygiene”. Targeted hygiene means understanding the
routes of spread of infection in the home and targeting hygiene measures at critical
points to prevent the spread. This risk-based approach suggests that the “critical
control points” for breaking the chain of infection are the hands, together with hand
and food contact surfaces, cleaning cloths and other cleaning utensils. Although this
is a useful “rule of thumb” ranking, it is not a constant. For example, although the risks
from toilets, sinks and floors relate mainly to the relatively lower risk of transfer from
these sites to hands, hand and food contact surfaces and cloths, this risk can
increase substantially where an infected family member has fluid diarrhea, or where a
floor surface is contaminated with vomit, urine or faeces.
Fig. 2 - Ranking of sites and surfaces in the home based on risk of transmission of
infections
Key to breaking the chain of infection in the home is the application of hygiene
procedures to critical surfaces (e.g. hands, hand contact and food contact surfaces)
at the appropriate time to eliminate pathogenic contamination. Since the “infectious
dose” for some pathogens can be relatively small, (10-1000 particles), the aim should
be to get rid of as many contaminants as possible. Decontamination of surfaces may
be achieved either by soap or detergent-based cleaning, the application of a
“microbicidal process”, (either heat or a chemical disinfectant), or a combination of
both. In general, for hand hygiene and for cooking and eating utensils, contamination
can be effectively removed using soap or detergent and hot water. The soap or
detergent helps to detach the organisms from the surface. The rinsing process then
removes the organisms from the surface leaving it “hygienically clean”.
In some cases however “rinsing” with water is not an option. Where surfaces are
cleaned with a cloth or mop without rinsing, this removes visible soiling and a large
proportion of the contamination, but still leaves behind some pathogens which can be
enough to cause an infection. In these situations, use of a chemical disinfectant (or a
heat process) that kills or inactivates these residual contaminants is advisable. Areas
where a chemical disinfectant may be required include larger surfaces that cannot be
adequately rinsed, such as bedside tables and food preparation surfaces, and
surfaces such as handles, toilet seats. It can sometimes also include floor surfaces
which have become contaminated by pet faeces or body fluids etc – particularly
where there is a crawling baby. Chemical disinfection or the combined action of heat
and a bleach-based laundry powder is also recommended for cleaning cloths, mops,
clothing, and linens because detergent-based cleaning is found to be insufficient to
detach microbes. Waterless hand disinfectants (also called hand gels, hand
sanitisers or hygienic handrubs) should also be recommended for situations where
access to soap and water for handwashing is limited.
Use of disinfectants is particularly advised in situations of high risk such as caring for
family members who are infected, or who are at increased risk of infection, in order to
give an increased overall risk reduction compared with that achieved by detergentbased cleaning alone.
What are Chemical Disinfectants?
Q: What are chemical disinfectants?
A: Chemical disinfectants are products that kill germs (harmful bacteria, viruses and
fungi).
Q: How do I know if the product I am using is a disinfectant?
A: Read the label carefully, if the product is a disinfectant, the label will say
“disinfectant” and/or “kills” germs or bacteria etc. Note: some commercial products,
e.g. bleaches, even though they are technically disinfectants say that they “kill
germs” but are not actually labelled as “disinfectants”.
Q: Do all disinfectants kill all types of germs?
A: No, so again read the label to check that the product will kill the types of germs
(bacteria, fungi and/or viruses) which may be present. All disinfectants kill bacteria
(called bactericidal). Some will also kill fungi (fungicidal), bacterial spores
(sporicidal) and/or viruses (virucidal).
Q: What is an antibacterial product?
A: “Antibacterial” means that the product acts against bacteria in some unspecified
way. Some products labelled “antibacterial” will kill bacteria whilst others may only
prevent them multiplying. So it is important to check that the product states that it
“kills” bacteria” An antibacterial is not necessarily anti-fungal or anti-viral and are
thus not suitable for use in situations where these organisms may be the problem.
Q: What is a “biocide”?
A: Biocide is a broad term for a substance that kills, inactivates or otherwise controls
living organisms. It includes antiseptics and disinfectants, which combat microorganisms, and also includes pesticides. The term microbicides is used to
distinguish agents which inactivate microorganisms
Q: When do I need to use a disinfectant?
A: As stated above, where surfaces are cleaned with a cloth or mop without rinsing,
this removes visible soiling and a large proportion of the contamination but still
leaves behind a small number of the pathogens which can be enough to cause an
infection. This means that, for critical surfaces (e.g hands, hand contact and food
contact surfaces etc) where thorough rinsing is not an option, use of a chemical
disinfectant that kills or inactivates residual contaminants is advisable. This
includes larger surfaces such as bedside table and food preparation surfaces, and
surfaces such as handles, toilet seats that cannot be adequately rinsed. It also
sometimes includes floor surfaces which have become contamination by pet
faeces or body fluids etc – particularly where there is a crawling baby. Chemical
disinfection or the combined action of heat and a bleach-based laundry powder is
recommended for cleaning cloths, mops, clothing, and linens. Waterless hand
disinfectants (also called hand gels, hand sanitisers or hygienic handrubs) should
be used in situations where access to soap and water for handwashing is limited.
Use of disinfectants is particularly advised in situations of high risk such as caring for
family members who are infected, or who are at increased risk of infection, in order to
give an increased overall risk reduction compared with that achieved by detergentbased cleaning alone.
Choosing a disinfectant product
Q:There are so many products to choose from, how can I choose the right
disinfectant?
A: Disinfectant products contain a variety of active ingredients and are suited to
different situations. When selecting a product, it is necessary to decide what the
key properties are that you need from the product. For example, consider the type
of germs you need to combat, what type of surface or material you need to
disinfect, whether you are dealing with small or large areas, whether the surface is
going to be used for food preparation. You may also feel that the scent of the
product is important.
Many disinfecting products are either bleach-based (either chlorine or oxygen-based
bleach) or alcohol-based. Other products contain a variety of active ingredients (e.g.
phenol, benzalkonium chloride, chlorhexidine, triclosan, pine oil) and so their
properties vary. This means that you will need to check the product packaging and/or
manufacturer’s instructions for the active ingredients and other information on its
properties and limitations.
Use the checklist and table below to help you choose the best disinfectant for a
particular purpose by asking ‘What properties do I need?’ and comparing it with ‘What
properties does the disinfectant have?’ If this information is not available contact the
manufacturer or your infection control team.
Q: What should be considered when choosing and using a disinfectant?
A: Disinfectants will only kill enough germs to make the surface safe if used at the
correct concentration and for the optimum contact time. At lower concentrations
the product may kill, or prevent growth of, some microbes, but will probably not be
enough to achieve “disinfection”. Some disinfectants need to be diluted, while
others (e.g. alcohol-based products) do not.
The choice of disinfectant and the concentration and contact time will depend on what
you want to achieve and the conditions under which the disinfectant must work.
The following are the most important factors you need to consider:
a) The type of germs
Some disinfectants are active against all types of germs (bacteria, viruses, fungi)
whilst some are only active against bacteria. Make sure that you choose a product
that has the right “spectrum” of action.
b) If soiled
If the surface, or object, that is being disinfected is soiled with dirt, food, faeces, pus,
or blood, the disinfectant will be less effective. This means you should either clean the
surface (or object) before applying the disinfectant, or you may use a combined
disinfectant cleaner. You may also need to use a higher concentration, so follow the
manufacturer’s instructions. In situations where surfaces are heavily soiled e.g. with
vomit and faeces, then you must remove as much of the “soil” as possible before
disinfecting. In doing so make sure you wear gloves, use disposable cloths and
dispose of the contaminated materials carefully.
c) Concentration and contact time
Some disinfectants will kill germs quickly; others need longer. Some types of germs,
e.g. bacterial or fungal spores, take longer to kill. So, again, read the label and leave
the disinfectant on the surface for the right length of time.
d) Hard water
Some disinfectants are affected if they are diluted in hard water. In general however
disinfectant products are tested to ensure that they are effective in hard water areas.
e) Presence of detergent or soap
Some types of detergents or soap inactivate some disinfectants. If you are using a
combined disinfectant cleaner, make sure you use a commercially formulated
product, don’t make up your own disinfectant/cleaner mixture. If you are going to
clean and then disinfect, rinse the surface to remove traces of detergent, before
applying the disinfectant.
f) Type of surface material
Make sure that the disinfectant is suitable for the surface you need to disinfect. Some
disinfectants have a bleaching action or can damage certain types of surfaces. Some
disinfectants are not safe for use on the skin.
Q: How long will the disinfectant action last
A: This depends on a number of factors. If a surface is dry it will stay “hygienic” until
reused, or recontaminated. If a surface is damp, e.g. a damp cloth, then the small
number of microbes not killed by the disinfectant can grow again within a few
hours. This is why targeted hygiene means hygienic cleaning of surfaces or
materials at the right time, so it is important to wash your hands not only after
visiting the toilet or handling raw meat or poultry, but also before handling ready-toeat food.
Q: What is a descalent?
A: It is a product that removes lime-scale. Some products can also prevent the build
up of lime-scale if used regularly. Some cleaning or disinfecting products may also
include a descaling ingredient.
Q: How do I know which laundry washing powders or tablets contain bleach?
A: Bleach-based laundry products are either powders (biological or non-biological) or
solid tablets. The term ‘oxygen-based bleaching agent’ should be listed in the
ingredients list on the packaging. Liquid laundry products and liquid capsules, or
products designed for coloured clothes (colour care products) do not contain
bleach.
Q: How do I know that the product will be effective?
A: All disinfectants should comply with standard tests for efficacy. Read the label or
refer to manufacturers instructions to make sure that the product meets these
requirements and can thus produce a satisfactory risk reduction.
European Standards include tests for efficacy on hard surfaces include tests for
bactericidal activity (EN 1276 and EN 13697) fungicidal activity (EN 1650 and EN
13697), sporicidal activity (EN 13704) and virucidal activity (EN 13610). The tests for
efficacy of handwashing formulations is EN 1499 and
In the US, standard tests of the Association of Official Analytical Chemists (AOAC)
are used to establish the efficacy of hard surface disinfectants. The ASTM (American
Society for Testing Materials) method ASTM1174 is used for evaluation of handwash
Formulations.
Q: What about alcohol hand gels – are they effective?
A: Waterless hand sanitizers such as alcohol-based products (referred to as alcohol
handrubs, alcohol hand sanitizers or alcohol hand gels) are recommended for use
in situations where soap and water is not available. They are also recommended
for use in addition to/after handwashing in high risk situations (e.g when caring for
someone in the home who is infected, after handling raw meat and poultry etc) to
give an “added margin of safety”. Alcohol hand gels are highly effective against
bacteria such as Salmonella, Escherichia coli and Staphylococcus aureus
(including MRSA). Alcohol hand rubs available to consumers are usually based on
ethanol. To be effective, the product should contain not less than 62% ethanol.
Alcohol-based formulations available to consumers mostly appear to contain 62%
ethanol, although the concentration is rarely stated on the label. In vivo panel tests
suggest that alcohol hand sanitizers are more effective than soap and water
handwashing in reducing bacterial contamination on the hands. Although alcohol
hand gels are relatively less effective against viruses compared with bacteria, in
vivo tests indicate that they are equally as effective as handwashing with soap
against the common viruses which spread in the home such as rhinovirus (cold
viruses), rotavirus, norovirus and adenovirus).
In vivo efficacy of ABHS have been carried out using methods based on a number of
in vivo studies have been carried out to determine the efficacy of ABHS in reducing
the release of viruses from hands. Test methods used were variants of the method of
Sattar et al.i or the ASTM method (ASTM 1174).
Selecting a disinfectant
What property
do I need?
What properties does the product have?
Bleach
(either chlorine-based e.g. sodium
hypochlorite or oxygen-based e.g.
hydrogen peroxide)
Alcohol
(ethyl or isopropyl)
Phenolics (e.g. Jeyes fluid)
and pine fluids
Products containing other
actives e.g. quaternary
ammonium compounds,
chlorhexidine, triclosan
Which types of
germs do I need
to kill?
Kills all types of bacteria, fungi, viruses and Kills bacteria, fungi. Also
Kills bacteria, fungi but only
bacterial and fungal spores at the
effective against some viruses effective against some viruses
recommended concentration*
including rhinovirus, norovirus,
rotavirus and adenovirus, but
not hepatitis A.
How quickly does
the product need
to act?
Are there any soil,
dirt or food
residues on the
surface?
How hard is the
water?
Acts very quickly (within 1 minute) but
Acts quickly (within 1 minute)
longer contact times are required for spores
Affected by soiling. If soiling is light, clean Not effective on dirty surfaces
and then disinfect or use a combined
or dirty hands
bleach/cleaner formulation. If heavily soiled
always clean before disinfecting
Not inactivated by hard water
Not relevant – products are
used undiluted
Efficacy can be reduced in the presence of soiling, so you may need to
use higher concentrations. Follow the manufacturers instructions
What type of
surface needs
disinfecting?
Suitable for hard surfaces, including food
contact surfaces) cloths and white laundry
Suitable for all types of hard
surfaces, sinks, drains etc. Not
suitable for food contact surfaces
Are there any
other possible
drawbacks?
Suitable for hands and small
surfaces e.g. work surfaces
thermometers etc
Action varies according to
concentration; some products are only
formulated to prevent growth of germs.
Active against bacteria and fungi but
tend to have limited action against
viruses.
Follow the manufacturers instructions
Varies, but action may be affected by hard water. Check the
manufacturers advice
Suitable for hands and small
surfaces e.g. work surfaces. Some
products (e.g. quats) suitable for
food contact surfaces.
Chorine-based bleaches could damage
May dry the skin, use one that Phenolics can have a strong odour. Can be inactivated by detergents
and/or bleach coloured fabrics carpets and contains an emollient
Can be inactivated by detergents
that may be in other cleaning
soft furnishings and erode metal surfaces
may be in other cleaning products. products.
*For bleach, e.g. chlorine-based, the recommended concentration can vary from as low as 250 ppm (for infant feeding bottles) and up to as much as 10,000 ppm (for treating
blood) according to how the bleach is to be used and what it is used for. Thus it is very important to follow the manufacturer’s instructions for use or if you are still unsure
consult your community infection team.
Evidence base
Further information on hygiene procedures in the home and their effectiveness can
be found at:
http://www.ifh-homehygiene.org/best-practice-review/hygiene-procedures-home-andtheir-effectiveness-review-scientific-evidence-base
Resources on Home Hygiene


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
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Guidelines for prevention of infection and cross infection the domestic
environment. International Scientific Forum on Home Hygiene. Available from:
http://www.ifh-homehygiene.com/best-practice-care-guideline/guidelinesprevention-infection-and-cross-infection-domestic
Guidelines for prevention of infection and cross infection the domestic
environment: focus on issues in developing countries. International Scientific
Forum
on
Home
Hygiene.
Available
from:
http://www.ifhhomehygiene.org/best-practice-care-guideline/guidelines-preventioninfection-and-cross-infection-domestic-0
Recommendations for suitable procedure for use in the domestic environment
(2001). International Scientific Forum on Home Hygiene. http://www.ifhhomehygiene.org/best-practice-care-guideline/recommendations-suitableprocedure-use-domestic-environment-2001
Home hygiene - prevention of infection at home: a training resource for carers
and their trainers. (2003) International Scientific Forum on Home Hygiene.
Available from: http://www.ifh-homehygiene.com/best-practice-training/homehygiene-%E2%80%93-prevention-infection-home-training-resource-carersand-their
Home Hygiene in Developing Countries: Prevention of Infection in the Home
and Peridomestic Setting. A training resource for teachers and community
health professionals in developing countries. International Scientific Forum on
Home Hygiene. Available from: www.ifh-homehygiene.org/best-practicetraining/home-hygiene-developing-countries-prevention-infection-home-andperi-domestic. (Also available in Russian, Urdu and Bengali)
This fact sheet was last updated in 2014
1.
i
Ansari SA, Sattar SA, Springthorpe VS, Wells GA, Tostowaryk, W. In vivo
protocol for testing efficacy of hand-washing agents against viruses and bacteria:
experiments with rotavirus and Escherichia coli. Applied and Environmental
Microbiology 1989;55:3113-8.