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Cleaning & Disinfection Principles. Key Terms. 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.
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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 • SanitationProcess 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 • 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
Detergent concentration Detergent composition Washing temperature Factors affecting cleaning Contact time Mechanical action Surface to clean
Cleaning Performance sensitive to factors like: • 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 Mechanical action Chemical action Time
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 • 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 • 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 • 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 • 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 • 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 . • 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.
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. • Acid detergents remove inorganic mineral deposits (scale) and stains such as those associated with hard water. • 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. • 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 • 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: - • 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 • 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 * 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
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 • 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.
Cleaning methods in Food industry • Manual & Mechanical • Wet & Dry • Immersion cleaning • COP • CIP • High Pressure sprays
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 and Mechanical - Wet Cleaning Methods
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.
This is how Foam is Generated 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 Air 40 - 60 psi Chemical H20 30 - 50 psi
Advantages of Foam Cleaning Process • 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 • 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 • 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.