L2 Food and Environmental Hygiene II 2024 PDF

Lecture 2 Food and Environmental Hygiene II FNSC5430/LSCI6843 Food Toxicology and Safety Gordon Cheung B.Sc.(Hons.), Pg.D. Diet., M.Phil., Cert. Chi. Med., R.D.(UK)  Content Practical Examples of Food Hygiene Practice...

Lecture 2 Food and Environmental Hygiene II FNSC5430/LSCI6843 Food Toxicology and Safety Gordon Cheung B.Sc.(Hons.), Pg.D. Diet., M.Phil., Cert. Chi. Med., R.D.(UK)  Content Practical Examples of Food Hygiene Practice Food Hygiene in Food and Catering Industry Personal Hygiene Environmental Hygiene Decoration and Equipment in the Food Rooms Ventilation in the Food Rooms Cleaning and Disinfection Pest Control Practical Examples of Food Hygiene Practice What is/are the Problem(s)? What is/are the Problem(s)? Examples of Good Storage Separate Utensil for Raw and Cooked Foods Thawing – What is the Problem?  Personal Hygiene of Food and Catering Industry  Personal Hygiene Food handlers must always keep up with a high personal hygiene standard to ensure food safety Good appearance Hair should be short and covered with hat Nails should be kept short and hand must be washed before handling food Heavy make-up, strong perfume or aftershave should be avoided Open wound should be covered by bandage Proper clothing - jewelry Food handlers should have their watches, rings and jewelry removed before entering food room to avoid unnecessary contamination  Personal Hygiene – Clothing and Personal Belongings Food handlers should wear disposable gloves when handling ready-to-eat food. They should be discarded if damaged, soiled, or when interruptions occur in the operation Food handlers should, as far as possible, wear mouth masks when handling food. They should be discarded when damaged, soiled, or after prolonged use Only clean and light coloured outer clothing or protective overalls should be worn. If they become soiled during food preparation, they should be changed or cleaned as necessary Buttons should preferably be avoided on the clothing as they may come off and fall on the food Shoes should be worn when entering food room Personal belongings, such as handbags, footwear, umbrellas and dirty clothing, should not be stored or left in any food preparation area. They should be put inside lockers or cloakrooms away from food preparation areas Personal Hygiene – Preparation Before Work Before commencing work, work uniform and aprons (or clothing) must be clean and fit for the purpose Choose light-coloured and easily clean material No pockets and avoid buttons Wear a clean hat or hair net, long hair should be tied back as well Shoes with no or low heel should be worn Wear mouth masks when handling food as far as possible Do not wear work uniform outside food handling area  Personal Hygiene – Hand Hygiene Hands frequently touch ready-to-eat foods Hands frequently touch contaminated objects Hands carry food borne pathogens Hand hygiene compliance is usually poor FDA estimate good hand hygiene would stop 20million cases of food poisoning per year in the US  Personal Hygiene – Hand Hygiene Experimental results on handwashing: When hand basin is used for hand washing, about 26% of the bacteria will remain With running water, about 20% of the bacteria will remain When soap is being used, almost all bacteria will be removed  Personal Hygiene – Hand Hygiene To avoid contamination, all food handlers should wash their hands: before commencing work before handling food after handling raw food after handling soiled equipment or utensils after handling animals or waste after coughing, sneezing, eating, drinking or blowing nose after touching their ears, noses, hair, mouths or other parts of their bodies after visiting the toilet after engaging in any activities that may contaminate the hands. (e.g. handling money, carrying out cleaning duties, etc.)  Personal Hygiene - Wet the hands with running water, preferably with warm water Apply liquid soap Rub hands for 20 seconds (wash all surfaces thoroughly, including forearms, wrists, palms, back of hands, fingers and under fingernails) If necessary, use a clean and sanitary nail brush to clean nails Rinse hands thoroughly Dry hands with a clean paper towel, continuous cloth towel in dispenser or air dryer Turn off the tap with a paper towel Use the paper towel to open the door knob  Personal Hygiene – Personal Health Staff with any symptomatic signs of illnesses or communicable diseases such as diarrhea, vomiting, fever, sore throat, abdominal pain should not be engaged in food handling Should report conditions of illnesses to employer or supervisor Immediately suspended from engaging in food handling work Open cuts or wounds on the exposed parts of their bodies should be completely protected by waterproof gloves or dressings. Bandages or dressings should preferably be in blue colour Bandages and dressings should be changed regularly Disposable gloves should be worn if there are wounds on the hands  Personal Hygiene – Personal Habits Food handlers should refrain from the following behaviours inside food room: Put personal effects such as handbags, footwear, umbrellas and soiled clothing in food preparation areas Smoking / spitting Chewing, eating, sneezing or coughing over unprotected food or food contact surfaces Sitting, lying or standing on any surface liable to come into contact with food Touching ready-to-eat food with bare hands or tasting food with fingers Combing of hair or touching hair or other parts of bodies such as noses, eyes or ears Combing of hair and fixing up hats in food handling area Handling cash and food simultaneously Wearing jewelry and ornament  Personal Hygiene - Suspension of Work of Food Handlers Operators of food premises should ensure that all food handling staff are: free from any symptomatic signs of illnesses or communicable diseases such as diarrhea, vomiting, fever, sore throat and abdominal pain etc. not carriers of food-borne diseases e.g. cholera, hepatitis type A not suffering from discharging wounds or sores on any exposed part of their bodies; or discharge from their ears, eyes or noses Food handlers suffering or suspected to be suffering from a communicable disease should immediately report their illness or symptoms of illness to the management and seek medical treatment. They should be immediately suspended from engaging in any work that may allow them to come into contact with food, food contact surfaces, food utensils and equipment Food handlers ordered by health officers to cease working or taking part in food business should have written clearance from health officers before resuming their work Environmental Hygiene of Food Premises  Environmental Hygiene Environmental Hygiene is very important to food business A hygienic working environment will: Enhance work efficiency Reduce food wastage Minimize chance of food poisoning incidents Minimize pest infestation problems Promotion of business reputation  Environmental Hygiene - General Design and Construction of Food Premises Food premises should be designed and constructed in such a way that they： Are appropriate to the activities they are used for Provide adequate spaces for food production and other ancillary facilities and equipment Minimize the likelihood of food contamination Facilitate easy cleaning, sanitizing and maintenance Prevent access or harborage of pests Keep out of dust, dirt, fumes, smoke or other contaminants Provide a safe and comfort environment for staffs and customers Common area which is within 6 m of the food premises should be free of litter or waste  Environmental Hygiene - General Design and Construction of Food Premises The layout of food premises should be designed in such a manner that work flow is in one direction as far as possible (i.e. receiving → storage → preparation → packaging / serving → transportation → retailing) Systematically design with designated working zone Adequate spaces are provided for food preparation, food storage, scullery, storage of equipment / utensils and installation of sanitary fitments Minimize the likelihood of cross contamination and the design is from low risk to high risk To avoid congestion in each zone Facilitate easy cleaning, sanitizing and maintenance Kitchen Layout and Work Flow  Environmental Hygiene - General Design and Construction of Food Premises Prevent access or harborage of pests and keep out of dust, dirt, fumes, smoke or other contaminants Food or clean utensils are not conveyed through an open space or open yard Incompatible areas (such as cloakrooms or toilets) are completely segregated from food rooms Customers going to toilet do not have to pass through a food room Walls, floor, door, false ceiling should be kept clean and in good repair and free of cracks, crevices and other defects  Environmental Hygiene - General Design and Construction of Food Premises Kitchens and Food Rooms Apportionment of food room areas in every restaurant/factory canteen should not be less than the minimum requirement as stated in the Food Business Regulation (Schedule 4 and 5) Food premises with larger GFA should have larger food room Internal surfaces of walls and partitions in kitchens and food rooms should be surfaced with smooth, light coloured, durable, non-absorbent and easily cleaned materials (e.g. glazed tiles or stainless steel) to a height of not less than 2 m. The rest may be limewashed or painted in light-colour Junctions between walls, partitions and floors should be coved (rounded) Floor surface should be washed with detergents at least once daily Wall Material of Food Room  Environmental Hygiene - General Design and Construction of Food Premises Kitchens and Food Rooms (Cont’d) Surfaces of ceiling should be smooth and preferably finished in washable paint to facilitate cleaning False ceiling should be installed with an inspection opening to facilitate cleaning False ceiling in kitchen should be avoided Floor should be surfaced with non-slippery, light coloured, non-absorbent and easily cleaned and durable materials (e.g. mosaic tiles) and be sloped towards a floor drain connected to a proper drainage system Carpets and mats should not be provided in food rooms, food storage areas, toilets and other wet areas. Use of duckboards is not allowed  Environmental Hygiene – Lighting and Abultion Facilities Lighting Adequate lighting Designed to avoid accumulation of dirt and be easily cleaned Protected with shatter-proof covers to prevent broken glass from falling onto the food in the event of a breakage Ablution Facilities Every food room should be equipped with at least one wash hand basin (1 WHB/20 staff) WHB made of smooth, durable, non-absorbent materials and easily cleaned (min. size 350 mm in length) WHB connected to public mains water supply, preferably with both hot and cold water supplies and connected to waste pipe If water is supply intermittently, it should be allowed to run continuously for at least 20 seconds for every supply  Environmental Hygiene - Scullery Facilities At least one wash-up sink in every food room and kitchen Every wash-up sink should be of glazed earthenware, stainless metal or other materials that are smooth, durable, non-absorbent and easily cleaned, with a size of not less than 450mm in length (measured between the top inner rims) Be connected to public mains water, preferably with both hot and cold water supplies, and fitted with a waste pipe with trap before being connected to a proper drainage system Be fitted with a drip board At least one sterilizer of not less than 23-litre capacity should be provided for sterilization of all crockery, glassware and utensils Alternatively, a mechanical dish washer should be provided or bactericidal agent may be used Mechanical dish washer or bactericidal agent should be of a type approved by the FEHD Sterilizer and Dish Washer Environmental Hygiene – Sewage and Waste Water Disposal Sewerage and plumbing systems should be maintained in good repair and in good working condition Floor drains should be easily accessible for cleaning and clearing of chokage be properly trapped, vented and connected to a proper drainage system Backflow of dirty or waste water into kitchen/food rooms or all other places in a food premises should be avoided No manhole should be situated inside any kitchen or food room All soil / waste / rainwater pipes inside any kitchen, food room or seating accommodation should be enclosed in pipe ducts constructed of impervious rust-proofing materials with a suitable inspection openings A box-type or underground grease trap should be installed to remove greasy water before discharge into sewerage system The grease trap should be cleaned at regular intervals Hand Wash Basin, Wash-up Sink, and Grease Trap  Environmental Hygiene – Toilet Facilities Toilets should be kept clean, free of dirt and obnoxious odor Number of sanitary fitments should be in accordance with the requirements laid down under Regulations 5 and 8 of the Building (Standards of Sanitary Fitments, Plumbing, Drainage Works and Latrines) Regulations, Cap. 123 Toilets should be of adequate size, conveniently located and easily accessible Be well ventilated and lit Be segregated and provided with self-closing doors Be provided with adequate toilet paper WHBs provided with adequate supply of soap  Environmental Hygiene – Waste Container Be sufficient in number to cope with the normal waste yield generated by the food premises Be constructed of strong and impervious materials Be provided with a close fitting cover or lid Waste containers should be properly covered Waste containers should be regularly and thoroughly washed by using detergent and clean water Waste must be disposed at least once daily Waste storage areas / rooms should be kept away from food rooms / kitchens and be well ventilated The walls, floors and ceilings should be designed and constructed in such a way that enables them to be easily cleaned Environmental Hygiene – Ventilation System Food premises should have sufficient natural or mechanical ventilation to effectively remove fumes, smoke, steam, heat and condensation arising from the food premises, and supply fresh air thereto. Adequate propulsion fans and extraction fans should be provided, with the point of intake or discharge being in the open air at a height of not less than 2.5m from the ground level and in such a manner as not to cause a nuisance A mechanical ventilating system should be provided to give not less than 17 m3/hr. outside air for each customer if natural ventilation is sufficient Ventilating systems installed in restaurants and factory canteen should comply with Regulation 4(1) of the Ventilation of Scheduled Premises Regulation, Cap. 132 Seating areas, kitchens / food rooms and toilets should have their own independent ventilating system Environmental Hygiene – Ventilation System Fresh air supply system fitted with propulsion fans with adequate capacity should be installed in food rooms and kitchens Cooking range inside kitchens and food rooms should be equipped with an exhaust system that can efficiently and effectively remove all fumes, smoke, steam or any vapour arising from food operations The exhaust system should be installed with a metal hood properly connected to an air-duct fitted with an extraction fan of sufficient capacity All exhaust should be arranged to pass through a grease filter and, if required, an air pollution control equipment (e.g. a water scrubber or electrostatic precipitator) before being discharged into the open air Cleaning and Disinfection  Cleaning and Disinfection - Food Industry Perspective “Monitoring cleaning is a vital component of cleaning management” “In isolation visual assessment is not a good indicator of surface cleanliness” Griffith, 2005 Handbook of Hygiene Control in the Food Industry  Why Cleaning is so Important Reasons for Cleaning in Addition to Food Safety Pleasant and safe environment (removes dirt and grease) More customer confidence (promotes favourable image) Removes bacteria and food on which bacteria grow Aids pest control (removes food and pests easier to see) Enables disinfection To comply with the law  Why Cleaning is so Important Reasons for Cleaning in Addition to Food Safety Reduction in: Food wastage Surface deterioration Customer complaints Wear and tear Physical contamination  BRC Global Standard for Food safety 2008 Section 4: 4.9 Hygiene and Housekeeping Cleaning procedures/schedules in place Trained personnel Cleaning chemicals fit for purpose Cleaning practices to minimise risk of cross contamination Effectiveness of cleaning verified and recorded Procedures revalidated  Cleaning vs Disinfection vs Sanitising Cleaning Removal of soil Disinfection Destruction or removal of microorganisms Aim: to reduce to an acceptable level - little or no risk Sanitising Cleaning process with an additional element of disinfection (detergent / disinfectant)  Typical Stages in a Cleaning Programme Stage Function Reason 1 Pre-clean Remove loose food or dirt, Improves efficiency of later stages, allows detergent scrape, vacuum, etc. access to more firmly adhering residues 2 Main clean Removes more firmly adhering Improves efficiency of later stages. Presence of dirt / food residue, grease or dirt. residue / grease reduce the efficacy of disinfectants Usually detergents used to emulsify food particles and reduce surface tension 3 Rinse Removes detergent and Improves efficiency of disinfection, minimises any emulsified / dissolved dirt and reactions between cleaning chemicals grease 4 Disinfect Further reduction in the number Minimises risk of cross contamination, increases of microorganisms product shelf life and safety 5 Final Rinse Removes traces of disinfectant Minimises risk of disinfectant contaminating the food 6 Dry Air dry or use disposable Residual moisture provides an opportunity for any materials to minimise remaining microorganisms to grow and survive and recontamination increases the risk of cross contamination Cleaning and Disinfection  Test for Cleaning Effectiveness? Useful in: Verification, Inspection and Audit Validation Monitoring Risk assessment Outbreak investigation Identification of reservoirs Education Cost efficiency and financial management  How to Test for Cleanliness: Characteristics of an Ideal Method Detects microorganisms and food residues with sufficient sensitivity Works equally well on wet and dry surfaces Repeatable / Reproducible Easy to use Rapid Cheap Recordable  Assessing Cleanliness No ideal method Microbiological Non-microbiological method ATP (Companies using ATP includes Nestle, Pepsi, Heinz) Protein Reducing Sugar Other  When to Run the Test of Environmental Surface Contamination After cleaning and disinfection Before production Commissioning After maintenance  Comparison of Microbiological and Non- Microbiological Testing Attirbute Microbiological (Cultivation) ATP (Adenosine triphosphate) Protein Acceptance Widely accepted by food Although not universally General less well accepted than industry worldwide accepted in the UK and many ATP but more recently other countries, acceptance has developed technique been increased rapidly over the past decade Method / principle testing Microorganisms derived from ATP derived from Protein from surface food surface grow and multiply. microorganisms and food debris transferred onto a swab Laboratory facilities, or at debris converted into light and or equivalent. Protein detected minimum, portable incubation detected using a by a colorimetric reaction and and safe disposal systems luminometer. No laboratory compared to colour standards. required facilities is needed No instrumentation or laboratory facilities required  Comparison of Microbiological and Non- Microbiological Testing Attirbute Microbiological ATP Protein (Cultivation) (Adenosine triphosphate) Time for results 18-48 hours 2 minutes 5-10 minutes Reproducibility for raw milk CV 84 – 300% CV 9 – 79% Not Applicable contaminated surface Approximate running costs 60-100p 95-155p 95-145p (in-house) Capital costs Variable but incubator £130- Luminometer Optional colorimeter available £2000 £900 -£2500 for some tests Autoclave £600-£10,000 Staff requirements Some level of microbiological Brief training in test protocol. Brief training in test protocol. training No specialised knowledge No specialised knowledge required required  Importance of Environmental Hygiene in Food Industry “Environmental surface sampling recognised as important. One study suggests if an organism is found in the environment there is a 70% chance of it getting into the food.” IAFP Rome 2007  Pest Control Common pests found in food premises include: Rats and mice insects such as flies and cockroaches Pests will not only pose food safety problems but also transmit diseases to human Reasons for pest infestation in food premises Improper storage of food Improper handling of food leftover Existence of food debris Accumulation of commodities including motley articles Dirty premises and floor Structural defects of buildings Other unhygienic conditions  Pest Control – Signs of Pest Infestation Eye spotting Droppings Odour Holes Runways Gnawing marks Feet marks  Rodents Common species of rodents in HK are : The causative agents could enter our body in Rattus norvegicus (Rn) four different ways Rattus rattus (R2) Through the ectoparasites of rat like fleas, ticks and mites Mus musculus (Mm) By food and water contaminated by rodent Common rodent-borne diseases excreta Plague Through direct contact with rodent excreta Urban typhus By rat bite Spotted fever Scrub typhus Hantaan fever Rat-bite fever  Rodents – Prevention and Control Measures Temporary measure: Direct disinfestations Use poisonous baits or traps Mix rodenticides with bait for rodent consumption Usually take 4-5 days to give effects Fundamental measure: Improve the sanitary condition of the environment Store food and cover waste properly, deprive rodent of food Clean and maintain places in good repair to eliminate harbourage for rodent Conduct regular rodent survey to early detect signs of rodent infestation for early disinfestation  Cockroach Most common insect pest Common species found in Hong Kong: American cockroach (Periplaneta americana) Australia cockroach (Periplaneta australasiae) German cockroach (Blattella germanica) American and German cockroach are most common Hazards caused by cockroaches: Produce odorous secretions and have adverse effect on food quality Carry pathogens on their surfaces which can cause disease including food poisoning, nausea, vomiting and diarrhea Carry a wide variety of harmful microorganisms inside their body Contain a number of allergens, in their excrement and their cast-off skins, which can cause rashes, watery eyes and sneezing  Cockroach - Prevention and Control Measures Leave no food for cockroach Keep premises, especially kitchen, clean and dry Store food properly, put all refuse and food remnant into refuse, tie up refuse bag tightly before disposal to avoid spillage Eliminate harborage for cockroach Clean up refuse and unused articles Inspect at least quarterly the bottom of equipment and concealed places like false ceiling, air ducts and wire ducts Seal all cracks and crevices at ceiling, walls and floor Poisoning Use insecticides with residue effect for killing the pest Set poisonous bait to kill cockroaches, the bait will not only kill those cockroaches consuming the bait, but also those in the harbourage indirectly  Fly Common Fly found in HK includes: House fly (Musca domestica) Blow fly (Chrysomya megacephala) Flesh fly (Sarcophaga spp.) Hazards caused by fly: Expel obnoxious smelling secretion which decay food Body surface carries pathogens which may cause diseases including food poisoning, nausea, vomiting and diarrhea Carry many pathogenic microorganisms in their bodies Excrement and shed off skin carries a number of allergens causing rash, watery eyes and sneezing  Fly - Prevention and Control Measures Good environmental sanitation Elimination of breeding places Proper collection, storage and disposal of refuse Screening Screen windows ventilation openings and doors with 10 mesh screens Install self-closing device to doors / screen doors Use anti-fly curtains by fixing strips of beads or plastic strips, etc. in doorways Install electric fans to create air curtains with air velocity 8m/s or more across doorway  Fly - Insect Electrocuting Device (IED) Use UV light to attract fly and kill by electrocuting Place along the most critical insect pathway and must be a warm place Place at about 3.6m (but not less than 3.6m) from entrance, distance between each device is about 12 to 15m 1.5 m above the ground Place at a place where the light is visible from all directions Do not place near sunlight and mercury vapour light Keep IED at least 1.5 m away from exposed food products (4.5 to 6 m is the best)