Definitions:
Cleaning:
Cleaning is the elimination of undesirable materials from dirt and soil from appliances and the surrounding enviroment which supports microbial growth.
Sanitization:
It is the practice of minimizing micro-organisms on the surface to a managable level.
Requirements of cleaning:
Bacteria count should not exceed 100/cm2 for TPC on any surfaces.
Requirements of a successful cleaning programme:
1) portable water supply
2) cleaning compounds such as Detergents (mechanical removal of soil and dirt) and Sanitizers (killing of micro-organisms)
3) proper cleaning procedures
DETERGENTS AND ITS VARIATIONS:
Alkaline
Detergents-
The ability to combine fats and oils to form soap and dissolve proteins.
The ability to combine fats and oils to form soap and dissolve proteins.
The higher the alkalinity
of the detergent, the more corrosive and effective it is.
Mildly alkaline
detergents are commonly used to remove soil from different surfaces such as
walls, table tops, floors, ceilings and other appliances and equipment.
Highly alkaline
detergents are used to remove stubborn stains and materials such as dried soil
and wax.
Examples: Sodium hydroxide (not recommended to be used
for metal equipment)
Highly corrosive on most surfaces especially
to the human skin.
Examples: Sodium Metasilicate Less corrosive as compared to Sodium Hydroxide
and it is safer to handle.
Tips: the temperature of
water used should not fall below 62oC to disallow any precipitation
of the detergent.
It is commonly used
with the aid of a high pressure spray to enhance the cleaning process.
Examples: Sodium Carbonate:
It is mildly alkaline and has less adverse effects as compared to Sodium hydroxide and Sodium metasilicate. It is also safer to handle.
It is mildly alkaline and has less adverse effects as compared to Sodium hydroxide and Sodium metasilicate. It is also safer to handle.
Acid Detergents
It is commonly used
to remove mineral deposits (eg. Calcium and Magnesium PPT) from surfaces and
equipment.
Acid detergents are
specialize detergents and have less adverse affects on soil which contain oils,
proteins and fats.
2 major types of
acid detergent would be organic and inorganic
INORGANIC
ACIDS: ORGANIC
ACIDS:
1) Known also as
strong or mineral acids. 1)Organic acids
have a milder effect than
2) Contains commonly
known acids such
Inorganic acids.
as Hydrochloric
acid, Nitric acid, Sulphuric 2) Contains commonly
known acids such as
acid and Phosphoric
acid.
Citric acid, Tartaric acid, etc.
3) Effective against
rust and mineral deposits.
It is less corrosive when applied on metal & However it is very corrosive and unsafe to has less irritation when in contact with the
It is less corrosive when applied on metal & However it is very corrosive and unsafe to has less irritation when in contact with the
handle with bare
hands. Human skin
Degreasers
Used to remove fats, oils and
greasy soil with high effectiveness as it has the ability to penetrate and
breakdown oil and fats into small particles which can then be
easily removed with water.
Degreasers contain
surfactants (allows surface tension of water to be reduced.)
Abrasive Detergents
Contains sand, quarts and pumics, it is usually in a powder or paste
form.
When applied to
surfaces, it requires mechanical cleaning such as scrubbing and polishing.
Surfaces should be
thoroughly rinsed with water to rid of any particles still present.
It is not advisable
to be used on metal surfaces as it causes scratches on metallic materials.
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