Cleaning & Disinfection
Principles
Key Terms
Cleaning
Removal of Visible physical dirt and stains. A clean surface is defined as being
free from soil (e.g. food residues), free from bad odours, be non-greasy to the
touch and have no visible oxidation (e.g. rust).
Disinfection Removal of harmful bacteria / microbes. A sanitized clean surface is defined
as a clean surface that is substantially free from pathogenic microorganisms
and undesirable numbers of spoilage microorganisms.
Sanitation
Process in which most or nearly all micro organisms (whether or not
pathogenic) killed through use of chemicals, heat, ultraviolet rays e.g. Milk is
disinfected by heating up to 100degree C for atleast 10 sec. to kill most
microbes (but not necessarily their spores) to make it more stable than
pasteurized milk
Total destruction of all microorganisms ( whether or not pathogenic) and their
spores, usually through the use of drastic methods such as concentrated
Sterilization toxic/ non toxic chemicals (Chlorine, formaldehyde, glutar-aldehydes, etc.),
very high temperatures, or intense radiation. A sterilized item cannot support
life in any from.
Key Terms - Description
Cleaning : The systematic application of energy to a surface or substance , with the
intention of removing dirt. Cleaning does not kill microbes.
Energy can be : Kinetic energy – physical, mechanical or turbulence
Thermal energy – hot water
Chemical energy – detergents
Disinfection : The process of killing pathogenic bacteria , but not spores and all viruses by
99.999% during a time frame greater than 5 but less than 10 mins. Commonly brought
about by heat or application of chemicals. Disinfectants have a higher level of germ kill
capability for pathogenic bacteria as compared to sanitizers.
Sanitation : The process of reducing microbes to safe levels ie a 99.999% of a
specific bacterial test population within 30 secs. Done by heat or chemicals. A
sanitizer may or may not necessarily destroy pathogenic organisms.
Sterilization : The process of destroying all microbes including spore forms.
Levels of “CLEAN”
• Cleaning
Removal of Visible physical dirt and stains
•Disinfection
Removal of harmful bacteria / microbes
•Sanitation
Process in which most or nearly all micro organisms
(whether or not pathogenic)
• Sterilization
Total Germ Kill live (including spores)
Why Clean and Sanitize?
Effective cleaning and sanitation programs are required to achieve the correct level of
hygiene in food handling or production facilities. If these are not adhered to there is a
greater risk of food becoming contaminated by pathogenic or spoilage
microorganisms.
There is also a risk of biofilms forming on factory and food preparation surfaces if these
programs are inadequate. Biofilms are complex aggregations of microorganisms and
other materials which enhance survival and growth of microorganisms; once formed
they are very difficult to remove.
Cleaning and sanitation programs include the following steps:
– routine procedures performed throughout and at the completion of food
processing or preparation on a daily basis
– periodic procedures required less frequently
– monitoring to ensure the procedures are performed correctly
– verification to check effectiveness of the program.
The safety of staff must be considered when developing these programs, including the
safe use of chemicals and hot water, and reducing manual labour.
Cleaning prior to sanitizing is recommended as it increases
the effectiveness of the sanitizing step.
What Should be Cleaned and Sanitized?
• All surfaces that may contact the food product, such as utensils, knives,
tables, cutting boards, conveyor belts, ice makers, ice storage bins, hands,
gloves, and aprons. Surfaces that do not directly contact the product such
as walls, ceilings, floors and drains have a profound effect on environment.
What Else Should be Cleaned and Sanitized?
• Cleaning tools like brooms, mops, squeegees, buckets, sponges, scrapers,
foaming equipment, water guns, etc., should be cleaned and sanitized.
Cleaning tools can be a major source of microbial contamination if not
cleaned. Cleaning tools should be washed and sanitized after every use.
They should be stored clean, dried, and secured.
Factors influencing cleaning & sanitation program
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Type of soil – organic , inorganic
Condition of soil – old soils difficult to clean
Supplies of water - Water hardness – difficult in hard water due to formation of
scale
Water temperature – higher temperatures are beneficial
Cleaning agent v/s surface being cleaned
Agitation or Pressure – scouring helps remove outer layer helping deeper
penetration of cleaning agent
Length of treatment – longer exposure is beneficial.
Concentration / composition of detergent.
supplies of energy
supplies of machines, equipment etc.
Cultural, religious and traditional values
Climate conditions
Infrastructure of the processing unit and Requirements for buildings
Awareness level of the staff
Definitions
• "Food" or “Foods”: includes any article manufactured, sold or represented for
use as food or drink (including water) for humans and any ingredient that may be
mixed with food for any purpose whatsoever.
• Food Transportation Unit: This includes vehicles, aircraft, ships, containers,
boxes, bulk tanks, trailers and any other transportation unit used to transport
food.
• "Perishable Food" means a food item or ingredient that is susceptible to
deterioration or loss of quality due to the microbial or enzymatic actions when
such foods or ingredients are subjected to temperature abuse.
• "Potentially Hazardous Food" means any food in a form or state which is capable
of supporting the growth of pathogenic microorganisms or the production of
toxins. Example for such foods involve meat, poultry, seafood, milk and its
products.
• Cross Contamination: it is the transfer of microbes or other food contaminant
from one food to another.
Basic Principles of Cleaning
What is “Clean Surface”?
– A clean surface is one that is,
• Free from Residual film or soil
• Should not contaminate food products
• Free from micro-organisms.
• What is Soil?
– Undesirable foreign matter on surfaces.
– A heterogeneous mixture of many substances
• Physical properties
• Chemical properties
• Cleaning in Aqueous solutions => complex process of interaction between:
– physical influences
– chemical influences
• Cleaning:
– the removal of poorly soluble residues by both water and aqueous surfactant
solution (detergent)
– dissolution of water-soluble residues
Factors affecting cleaning
Detergent concentration
Contact time
Detergent composition
Mechanical action
Washing temperature
Surface to clean
Cleaning Performance sensitive to factors like:
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Type of surface
• Stainless Steel, Mild Steel, Aluminium, Brass, Glass & Ceramic, Plastic, Wood
etc.
Soil type
• Water soluble material
• Water insoluble material
– Chemistry
– Water quality
Cleaning technique
• Manual or Mechanical.
Factors affecting Cleaning – Sinner’s Circle
Temperature
Temperature
Mechanical
action
Mechanical action
Chemical action
Time
Time
Chemical action
Science behind cleaning
 Different types of soil
– Oily & Fatty soils, Proteinaceous soils, Carbohydrate soils
 Different types of surfaces
– Fabric, Stone, Metal, Ceramic
 Cost and Productivity
– Cleaning within “available” time
– Optimization of costs
Scientific processes are needed to effect “optimal” clean
Current Pressures on Food Industries
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Assure the safety of food products
Up-gradation to higher quality products
Reduction in Cost
FSSA had also put pressure on Industries to maintain and upgrade quality
standard.
Factors affecting Quality of a Food Product
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Input quality (Raw Material, Packaging Material etc.)
Manufacturing Practices
Personal Practices
Transportation Practices
Cleanliness and Hygiene Standards etc.
It is next to impossible to achieve quality and safe food
without following Proper Cleaning & Hygiene Systems.
Results of Improper Cleaning
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Poor Quality Food
Food-Unsafe for Human Consumption
Increased Utility Consumption viz. Steam, Water, Refrigeration etc.
Wastages & Reduced Safety
Increased level of chemical usage
Risk of Brand Damage
Continuous deposition of soil on surfaces, which may become difficult to
remove even manually
• Affects economy of production adversely
A well designed cleaning protocol shall result in:
• Improved productivity and organizational profitability
• Lesser time for cleaning, thus increased time for production
• Better operational efficiencies with savings in Water, Steam, and Electricity
etc.
• Peace of mind to management
• Improved Employee Satisfaction and Efficiency
• Better Safety etc.
• An effective cleaning can be defined as cleaning to a satisfactory level with
optimum costing.
• Cleaning process comprises of various tools in use, cleaning process and
process parameters and cleaning chemicals.
• Effective cleaning is not achievable without putting a system in place and
continuous trainings.
Cleaning and Sanitizing of Food contact Surfaces
Clean, sanitary food contact surfaces are fundamental to the control of
pathogenic microorganisms. The contamination of food either through
direct or indirect contact with insanitary surfaces potentially compromises
the safety of the product for consumption.
The effectiveness of the cleaning and sanitation program relates to the
implementation of the cleaning procedure, rather than the type of sanitizer
used.
The selection of detergents and sanitizers, their concentrations and the
method of application will depend on factors like
– Nature of soil
– Degree of cleaning and sanitation required
– Type of surface to be cleaned and
– Type of equipment used for cleaning and sanitation
Cleaning and Sanitation program
The cleaning and sanitation program of food contact surfaces typically
involves five steps
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STEP – 1 - Dry clean
STEP – 2 - Pre-rinse (brief)
STEP – 3 - Detergent application ( may include scrubbing)
STEP – 4 - Post – rinse and
STEP – 5 - Application of a sanitizer
STEP 1 - Dry cleaning
• Dry cleaning is simply using a brush or squeegee to remove the food
particles and soil from surfaces.
• Different equipments like brooms, cleaners, water sprays may be used to
push the particles form effected surfaces to the drains.
• This process may result in significantly removal of unwanted surface
matter and thus reducing the load of contamination.
• However, it not planned properly may create problems associated with
clogged drains, handling of wet waste solids. Its also tends to disperse dirt
and bacteria to other areas of plant and may lead to cross contamination
to other areas of plant. ( i.e. walls, equipment and tables)
STEP -2 - Pre- rinsing
Use of water or any other agent to remove small particles missed in the dry
cleaning step and prepares (wet) surfaces for cleaning application.
However, scrupulous removal of particulates is not necessary prior to
detergent.
STEP – 3 - Cleaning Process
Effectiveness of cleaning process will depend on – Type of Soil and Soil Load
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Product processed
Point in processing environment
Interior or exterior of equipment
Residence time
Temperature
What is soil?
Soil is any unwanted matter on the surface of an object that one desires to be
clean. It is undesirable foreign matter on surfaces. In general a heterogeneous
mixture of many substances. Special care must be taken to ensure that all soil is
removed and that it is not redeposited on the substrate.
- Physical properties
- Chemical properties
Characteristics of Food Soils
• Soil may be classified as visible and invisible, the latter category being primarily
microorganisms, such as bacteria, yeasts, and molds.
• Some food soils can be dissolved in water such as simple carbohydrates (sugars),
some simple mineral salts (NaCl), and some starches. There are also food soils that
dissolve in alkali, like proteins, starches associated with proteins or fats, and
bacterial films (biofilms). There are food soils that dissolve in acid, like hard water
hardness salts (calcium and magnesium salts), and more complex mineral films,
including iron and manganese deposits. Some also that dissolve with surfactants,
which include fats, oils and greases, many food residues, inert soils such as sand,
clay, or fine metals, and some biofilms
Types of soils : - Soils may be either Organic in nature of Inorganic in nature
Organic soils – like from Carbohydrates, Proteins, Fats etc.
• Such as those found in animal fats - vegetable oils, blood, protein, starch and
sugars.
• tannin, which is commonly found in tea - coffee and wine.
Inorganic soils – Salts, Minerals, like Water hardness salts etc.
• Such as scale in kettle; oxidized metal such as rust mineral deposits from food /
drink ( phosphates & oxalates )
• calcium salts such as milk stones
Cleaning
Cleaning Process
– Primary step
• removal of soil from substrates
– Secondary step
• stabilisation of dispersed or dissolved soil in the wash liquor to
prevent re-deposition (long term effect)
• Detergents react with soils to change their chemistry so they will dissolve
into the water and be carried away.
• Detergents modify the nature of water so that it may efficiently penetrate,
dislodge, disperse and carry away surface soils.
Types of cleaning agents
Four categories of cleaning agents :
 Detergents
 Solvent cleaners
 Abrasive cleaners
 Acid cleaners
Cleaning Agents - Detergents
Detergents - A detergent is a surfactant or a mixture of surfactants with "cleaning
properties
in
dilute
solutions."
These
substances
are
usually
alkylbenzenesulfonates, a family of compounds that are similar to soap but are
more soluble in hard water.
Detergents contain surfactants ( surface acting agents ) that reduce surface tension
between soil and surface so that soil can be penetrated and removed. Types of
detergents
• General Purpose (GP)
• Alkaline
• Chlorinated ( Chlorinated alkaline);
• Acid
• Enzymes
• General purpose detergents are mildly alkaline and used to clean up fresh soil
from floors , walls , ceilings, equipment, utensils, etc .
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Alkaline or Chlorinated Alkaline detergents are recommended for most processing
plant applications and are effective then GP’s. Alkaline detergents range from
moderately alkaline (Caustic). Smoke houses, cooker surfaces may require highly
caustic cleaning chemicals and application methods.
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Chlorinated products are usually more aggressive in loosening protein based soils
or for surfaces that are difficult to clean due to their shape or size, such as
perforated storage crates and waste containers. They are also alkaline and many
more corrosive. They should not be used on corrodible material such as
Aluminium.
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Acid detergents remove inorganic mineral deposits (scale) and stains such as those
associated with hard water.
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Emzymes are specific to a given soil type. These detergents are tailored for protein,
oil or carbohydrate based oils. Carbohydrate soils mostly occur where breading,
batters or starches are used.
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In situations where exposure to excess alkaline or acid conditions are a problem,
such as with waste water discharge restriction or equipment susceptible to
corrosion enzyme detergents may be an acceptable alternative.
Cleaning Agents – Solvents, Acid cleaners, Abrasive
cleaners
Solvent Cleaners :Often called degreasers
 Alkaline detergents containing grease dissolving agent.
 Useful for grill back splashes, oven doors, range hoods, etc
 Effective usually at full strength
Acid cleaners
 Used on mineral deposits eg. Scale
 Used in ware-washing machines , steam tables,
 Used for rust stains and tarnish on copper and brass.
Abrasive cleaners –
 Contain a scouring agent like silica that help to remove hard – to – remove
soil.
 Often used on floors or to remove baked on food in pots and pans.
Effectiveness of detergents depends upon
For an effective detergent and soil cleaning effectiveness will depend upon
several basic factors
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Contact time
Temperature
Physical disruption ( scrubbing) and
Water chemistry
Contact time: - Detergents do not work instantly but require time to
penetrate the soil and release it from the surface. Setting up soak tanks is
method to increase the contact time. When working with alkaline and
chlorinated detergents, employees should wear appropriate clothing such
goggles, tall boots or fully protective suits.
Temperature - Most chemical activities increase with increasing temperature. This
generally holds true with detergent efficiency, but with some more exceptions.
Many styles of steam cleaners are available are available which allow better
penetration of detergents and help in removal of soil. In some case water is used
for initially wetting and detergent cleaning and then rinse at 140 – 160 degree F,
this improves effectiveness with less risk of food soil left over.
For certain applications such as smoke houses, highly caustic detergent or alkali
(Caustic soda) is heated to 180degree F or hotter. The conditions chemically alter
and disperse soils such that denatured food residues are not likely to develop.
Disruption (Scrubbing) – Appropriate methods include brushes, pads and pressure
spray depending on the application. The selection of proper detergent methods
will minimize the need for manual scrubbing.
Water Chemistry – Final rinsing with water to drain the soil, nature, source and type
of water used effects the method of cleaning and sanitation.
STEP – 4 – Post Rinse
• During post rinse – water is used to remove detergent and loosen soil
from food contact surfaces.
• This process perpares the cleaned surfaces for sanitation.
• All the detergents must be removed in order for the sanitizing agent to be
effective.
STEP – 5 - Application of a sanitizer
After the food contact surfaces are cleaned, they must be sanitized to eliminate or
atleast suppress potentially harmful bacteria. Many type of chemical sanitizers are
available. They may or may not require rising before the start of processing,
depending upon sanitizer concentration. All sanitizers must be legally approved and
used only as per the MSDS (Material safety Data Sheet) provided by the chemical
manufacturer.
Application method
While using sanitizer a recommended dosage and application method of proportioners
and applicators must be used. These proportioners and applicators can be installed
in-line, on-line or at a separate stations.
A range of procedures can be used from manual mixing to fully automated system may
be applied.
Some sanitizers such as quaternary ammonium compounds (quats or QAC’s_ may eb
applied as foam with same equipment used for detergent foam application.
Effectiveness of sanitation process depends upon: •
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Sufficient contact time and
Coverage of the sanitizer
Dosage of sanitizer
Types of microbes and load of microbes.
Temperature
Sufficient contact time and coverage is sometimes best assured by the use of sanitizers
dip tanks for utensils and equipment parts.
Sinks and cleaning sanitations can be applied with protioning devices that mix and
deliver sanitizers in the prescribed concentration
Bulk containers or reservoir fitted with auto dosers which minimize maintenance, control
of chemicals usage and may reduce monitoring.
For control of common soil microorganisms, such as Listeria and E.coli footbaths are
frequently used as a part of plant sanitation program.
An ‘Ideal’ Sanitizer
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Acceptable toxicity
Wide, non-selective spectrum
Rapid action
Reasonably soil tolerant
Non corrosive
Compatible with cleaning materials
Useable in ambient conditions
Easily measured and monitored
Free rinsing
Non-toxic to the environment
Cost effective & safe to handle.
Sanitizers concentration commonly used in Food Plants
Sanitizer
Food contact
surface
Non food contact
surface
Chlorine
100-200* ppm
400ppm
Iodine
25* ppm
25ppm
Quats
200ppm*ppm
400-800*ppm
Chlorine dioxide
100-200* #ppm
100-200# ppm
Peroxyacetic acid
200-315*ppm
200-315ppm
Plant water
3-10 ppm
1-3#ppm
* The higher end of the listed range indicates the maximum concentration
permitted without a required rinse ( surface must drain)
# Includes mix of oxychloro compounds
Source 21 CFR 187.1010
Types of Sanitizers
Chlorine Sanitizers
Unfortunately no deal sanitizer exists for every requirement.
Chlorine sanitizers
Chlorine and products that produce chlorine comprise the largest and most common
group of food plant sanitizing agents. Chlorine sanitizers are effective against a
wide range of bacteria and molds. They work well at cool temperatures and
tolerate hard water. They are also relatively inexpensive. Household bleach is a
solution of sodium hypochlorite, a common form of chlorine.
Chlorine exists in more that one chemical state when dissolved in water. The
effectiveness of chlorine sanitizers is proportional to the hypochlorous acid in
solution; the most effective chemical form of chlorine.
The percentage of hypochlorous acid increases as alkalinity (pH) is decreased. The pH
of some water supplies is artificially elevated, which reduces the effectiveness of
chlorine. The Chlorine is very unstable at low pH and may dissipate prematurely
without killing bacteria.
Also, NEVER mix Chlorine and Ammonia
Hypochlorite's :- These are the most common chlorine sanitizers. They are available as
liquid concentrates on in dry granular form. The granular chlorine products are
sometimes reffered to as bleaching powders.
Chlorine dioxide : - Chlorine di-oxide does not form hypochlorous acid but dissolves in
water to produce a solution possessing strong oxidizing properties, It can be more
effective that chlorine in terms of ability to kill or reduce bacteria and retains some
anti microbial function in the presence of organic soils. It is particularly useful for
destroying bacteria bio-films. It is also less corrosive to stainless steel and less pH
sensitive than chlorine.
Chlorine di-oxide is unstable and must be generated on site. It is potentially explosive
and very toxic if improperly controlled – important consideration when selecting
this sanitizer.
Disadvantages of chlorine sanitizers
They can be corrosive to equipment and may form organochlorine by – product of
environmental concern effluent. Chlorine is inherently unstable solution, requiring
frequent monitoring and replenishing to maintaining adequate concentration.
A common misconception is that the chlorine content of a sanitizer can be confirmed
by odour. A used solution that still smells like chlorine may have little or no active
chlorine available for killing microbes.
Quaternary Ammonium compounds as Sanitizers
Quaternary Ammonium compounds, or more commonly know as quats or QAC’s.
These relatively need a longer exposure time to achieve significant kills. These are
very stable and continue to kill bacteria long after most sanitizers lose their
effectiveness. They have a stronger residual effect, even in the presence of some
soil, they are often selected for footbaths, floors and cooler surfaces. These are
effective against Listeria Monocytogenes and are commonly used in facilities that
produce ready to eat products.
Limitations
• Quats exhibit selective to different types of microorganisms they kill.
• On shifting from other sanitizers to Quats, there may be chance incident of
establishment of coliform or spoilage organisms in the environment, which may
then transfer to the products.
• These may exhibit effective results when altered with other sanitizers one or two
times a week.
• If detergents are not thoroughly rinsed from surfaces prior to applying quats or the
sanitizer will be chemically neutralized.
Iodine based sanitizers
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Iodoine based sanitizers, know as Iodophors are formulated with other
compounds to enhance their effectiveness They offer desirable features in a
sanitizer. They kill most types of micro organisms including yeast and molds even
at low concentrations.
They tolerate moderate contamination with organic soils and less corrosive and pH
sensitive than chlorine and are more stable during storage and use. They are less
irritating to skin than chlorine and often selected for hand dips.
Iodophors have an amber to light brown colour when properly diluted which can
be useful for monitoring since colour indicates the presence of active iodine. Test
strips are available for more precise monitoring.
Disadvantages of Iodophors as sanitizers
• The principal disadvantage of iodophors is staining, especially on plastics
• These sanitizers take a longer time to kill microorgansms at low temperatures than
does the chlorine and is rapidly vaporized and inactivated above 120degree F.
Iodophors must be specially formulated for use with hard water.
Acid sanitizers
These include acid anionic and carboxylic and peroxyacetic acid types. The advantage in
application of these sanitizers is that these are stable at high temperatures or in
presence of organic matter. Being acids, they remove inorganic solid, such as hard
water mineral scale, while sanitizing. These are commonly used in CIP or mechanical
cleaning systems.
The Carboxylic acid sanitizers, commonly known as fatty acid sanitizers, these are
generally more effective than acid – anoinic against a range of microorganisms types.
Peroxyacetic acid are produced by combining hydrogen peroxide and acetic acid. This
sanitizers is highly effective against most microorganisms of concern, especially in
biofilms which would otherwise protect bacteria. They are fast acting even at low
temperatures, tolerate some organic soil and degrade to form environmentally safe
products.
Disadvantages of acid sanitizers – Water chemistry is important since these sanitizers
are inactivated by certain metal ions, such as iron, and become quite corrosive when
mixed with water containing high chloride levels e.g. wells with high salinity levels.
Other Sanitizing Agents
Other sanitizing agents include ozone, ultraviolet light and hot water. Ozone is an
unstable oxidizing gas that must be generated on-site, contributing to its relatively
high cost. It is a more aggressive sanitizer than chlorine but requires careful
monitoring to prevent the release of excessive levels of the toxic gas.
Ozone, like chlorine, is dissipated when in contact with organic soils. It can be injected
into water system, as an alternative to chlorine gas, to make it safe for processing.
Ultraviolet ( UV ) irradiation is sometime used for treating water, air or surface that
can be positioned in close proximity to UV generating lamps. Ultraviolet does not
penetrate cloudy liquids or below to surfaces of films or solids.
It has no residual activity and cannot be pumped or applied onto equipment like most
chemical sanitizers.
Sanitizers - sanitizing methods
Spray Sanitizing
Use of spray to sanitize equipment surfaces
CIP Sanitizing
Sanitizing by circulation of the chemical agent inside pipeline and
equipment.
Immersion / COP
Sanitizing
Sanitizing equipment by immersion in a tank of sanitizing solution
Fogging
Fogging the chemical agent to sanitize the air and surfaces in a room.
Chlorine
All food contact surfaces, sprays, CIP, fogging
Mixed Halogens
All food contact surfaces, CIP, spray sanitizing
Iodine
All food contact surfaces, spray, CIP, approved as hand dips.
Peracetic Acid
All food contact surfaces, CIP, especially cold temperatures and
Carbon di oxides environments.
Acid Anionics
All food contact surfaces, CIP, spray, combined with sanitize and acid
rinse step into one.
QUATS
All food contact surfaces, mostly used for environmental control:
walls, drain and tiles
Cleaning methods in Food industry
Manual & Mechanical
•Wet & Dry
•Immersion cleaning
•COP
•CIP
•High Pressure sprays
Manual and Mechanical - Wet Cleaning Methods
Manual - Wet mopping –
One/two bucket systems, apply detergent solution to
emulsify/absorb dissolved dirt. Longer dry time
Manual Scrubbing Single disc w/water tank e.g. Stripping coated
floorings
Automatic Scrubbing –
Machine scrub/dry floor in one operation. Cleaning of
medium to large areas.
Wet vaccum cleaning –
Pick-up residual liquids /water, drying floor
Manual cleaning Advantages and Disadvantages
Manual Cleaning Advantages
 Parts can be cleaned without complete immersion in the cleaning solution.
 Additional cleaning equipment, such as wash and rinse tanks, is not necessary.
 Waste disposal requirements are kept to a minimum.
Manual Cleaning Disadvantages
 It is a labor-intensive process,
 require additional time to complete.
 Cleaning efficacy ??
 Cleaning Solution consumption is higher,
 Limitation on use of aggressive chemical.
 There is no reclaim of cleaning solution.
Mechanical Cleaning and Sanitation
Wet Cleaning - Foam / Gel Technology
•Use of high foaming solution to increase the retention time on the vertical
surfaces
•Gels are used to further increase over foam the retention time on the
vertical surface
This is how Foam is Generated
Chemical
H20
30 - 50 psi
Air
40 - 60 psi
Advantages of Foam Cleaning Process
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Mechanized Cleaning Process
Applied at Low pressures
High chemical / soiling contact time
Safe for operators as little aerosol is formed
Hence more aggressive chemicals can be used
Uses significantly less water than pressure cleaning
Reduces cleaning time
Minimizes risk of cross contamination
Improved Cleaning efficiency
Better cleaning economy
Improved working environment
Satisfied cleaning personnel
Better environmental accountability
Centralised Foam Cleaning systems
•No concentrated chemicals in production
area.
•Less handling of chemicals. One setting of
concentration
De centralized Foam Cleaning System
•Al operators can select rinse, foam or
disinfection.
•Detergent at each cleaning point
Mechanical – Dry Cleaning
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Manual or Automated
Use of Brooms/ Shovels
Use of automated Vaccum cleaners
Process used where wet cleaning is not possible
Areas manufacturing water sensitive products
Immersion Cleaning
•
This is the type of cleaning in which the parts to be cleaned are placed in the
cleaning solutions to come in contact with the entire surface of the parts.
•
Immersion cleaning is preferred for parts that must be placed in baskets and for
processes requiring a long soaking time because of the type of contamination to be
removed or the shape of the parts to be cleaned.
It is the most effective method, even if not the fastest one, and can be used with any
type of cleaner for any process, heated or at room temperature. Immersion
washers can be portable or stationary; single or multi-compartment; and are
available with a variety of options, controls and valve configurations including CIP
capability. The important aspects during design of immersion washer should be
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To minimize cycle time
Lower chemical usage
Reduce water and utility costs
Performance for immersion cleaning can be improved by moving the parts
within the liquid or with agitation of the liquid, mechanically or with the
addition of ultrasonic energy.
Mechanical – COP (Cleaning Out Of Place)
Cleaning Out of Place is defined as a method of cleaning equipment items by
removing them from their operational area and taking them to a designated
cleaning station for cleaning. It requires dismantling an apparatus, washing it in a
central washing area using an automated system, and checking it at reassembly.
Automated Parts Washer
Automated controls:
- Contact Time
- Temperature
COP Mechanical Action (agitation)
Push - Pull Action
Side Jet Action
Combination
Mechanical cleaning - CIP
Cleaning in place can be described as the cleaning of equipment and vessels at the
same place without movement of them to a different place. The cleaning agents
can be transferred to the vessel or equipment types either thorough fixed piping
or flexible hoses. The CIP process can consist of the following elements:
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Supply pump
Return pump
Heat exchanger with Black/Plant steam supply
Chemical tanks i.e Acid, Alkali tanks
Supply Pressure gauge or transmitter
Supply temperature sensors
Conductivity meter with sensor
C.I.P. Basic Requirements
Mechanical cleaning – High Pressure cleaning
Use of High pressure spray device assists in the removal of soil
High Pressure Advantages
• Good for Removal of Difficult or burnt soil
• Lowest Water Usage
• Works Against Broad Range of Soils
Cleaning Standards
Cleaning standards can be determined through:
 Visual test
 General appearance
 Microbiological test
 contact agar method
 swab/rinse method
 rapid hygiene test.
Verification of cleaning and sanitation methods
Monitoring to assure a clean and sanitary processing environment processing is required
regulation. Various methods are used by different organizations to verify
effectiveness of cleaning and sanitation programms.
Commonly used methods include
1.
Test strips – Strips are simply are soaked directly in the solution to be tested, a
change in colour indicates the presence of the sanitizers, the shade or intensity of
which relating to the concentration of the chemical. These are very rapid, low
cost, do not require any laboratory equipments or chemicals, can be performed
on site, and require very little training. E.g. Chlorine indicator test strips.
2.
Contact plate – Contact plates contain agar which has a convex surface. These
plates are pressed against the surface of equipment then incubated. Examination
of the plate will give an organism count and individual colonies can be lifted from
the plate and identified.
The surface of the equipment touched by the contact plate must be cleaned of any agar
residue. This method is used for verifying periodic effectiveness of cleaning and
sanitizing plant surfaces. The test procedure is very simple and requires no
additional special equipment and little training. Most contact plates are simply
touched to the surfaces to be tested then covered with a protective cap.
3. Swabbing - A sterile cotton or calcium alginate swab is wetted in sterile buffer, saline
solution, or broth and rubbed over a measured portion of the surface of the
sanitized equipment. The swab is then either streaked across an agar plate or
placed into a sterile broth tube.
The plate or tube is incubated for the appropriate length of time. Examination of the
plate will give an organism count and the individual colonies can be lifted from the
plate and identified. Tubes are examined for turbidity. This is a pass / fail test.
Swabbing is very useful for irregular surfaces or curved equipment
Limitation to microbiological testing methods
1.
These are slow and do not reveal problem in time to correct them prio to
processing.
2.
Manual errors may lead to variation of results.
3.
Test Protocols and test method are easily available. However, results may not
often be conclusive due to lack of reference data.
4. Luminometry (bioluminesence) is based on the enzymatic reaction responsible for
firelfly’s light. In this testing method, the brightness of light is propotional to the
amount of bacteria and food debris on the surface. In a typical test, a food contact
surface is swabbed following sanitation.
Material is swabbed and is placed inside an instrument that measures light
production. The instrument generates a value related to the quantity of cellular
material, such as bacteria. In some instances the residual food can provide high
reading when the load on the surface is quite low. Microbiological techniques, are
required for ore specific testing such as coliform bacteria count.
5. Final Rinse Test: Water of known microbiological quality and volume is rinsed
through the equipment. The water is recovered and filtered via membrane
filtration technique. The membrane is placed onto a plate and incubated.
Examination of the plate will give an organism count and individual organisms can
be identified. Note that rinse water analysis may not detect the presence of
biofilm on equipment surfaces.
Cleaning & Sanitation – Microbiological Aspect
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Microbes need Water and Food for growth.
Most of food products are high in water activity.
Food product contact surfaces may harbor microbes and provide the shield to
exterior factors.
Bacteria take exponential route for the growth and one bacteria doubles in average
20 minutes.
A non-clean, improperly clean surface may create a risk to food product and its user.
Critical for surfaces, coming in direct contact with food.
A suitable disinfectant should have
• Broad Spectrum for killing microbes (viz. all groups – Bacteria, Yeasts,
Molds, Viruses etc., Gm+ve & Gm-ve etc.)
• Should be sporicidal if required
• Rinse free or easy to rinse
• Should not affect MOC
• Safe and easy to use
Detergent-disinfectant can provide cleaning and sanitation simultaneously, thus
saves water, energy, time and manpower
Monitoring steps in the cleaning program should include:
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Visual inspection post cleaning to ensure any visible food residues have been
removed
Temperature checks for water and chemical solutions (using a calibrated
thermometer or temperature recorder) to ensure they are within the ranges
specified in the Standard Operating Procedures (SOP)
Concentrations of detergents and sanitizers are within the ranges specified in the
SOP
Timing devices used to ensure adequate contact times are operating correctly
Records are checked against procedures outlined in the SOP.
Verification of the effectiveness of the program is required on an ongoing basis and
ranges from simple procedures that can be performed in-house to more complex
testing that may need to be outsourced:
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looking, touching and smelling –
Microbiological testing of equipment and surfaces
ATP (adenosinetriphosphate) fluorescence testing can be used to detect the
presence of microorganisms and food residues
Equipment used for cleaning and sanitizing should be kept in good working order
so it does not become a source of contamination itself.
Cleaning and sanitation schedules
Cleaning and sanitation program and its schedule should be based on the importance
of the processes, its impact on food safety, the intensity and priority needed.
The schedules should define when and how different items and areas should be
cleaned and who to do the cleaning.
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What is to be cleaned
Who is to clean it
When it is to be cleaned
How it is to be cleaned
The time necessary to clean it
The chemicals used
Materials and equipment to be used
The cleaning standard required
The precaution to be taken
The protective clothing to be worn
Who is responsible for checking and recording that it has been cleaned.
END OF PRESENTATION