Food Safety

• Conditions needed for bacterial growth

  • Warmth
  • Moisture
  • Food
  • Time
  • Suitable pH range
• Warmth

  • bacteria reproduce rapidly in warm temperatures
  • 5-63 degrees is the danger zone, where rapid growth of bacteria
  • Cold temperatures are where bacteria re dormant (stop growing)
  • Cannot survive in very hot temperatures
  • Fridge = 1-4 degrees Celsius (reproduce slowly)
  • Freezer = -18 degrees Celsius
  • Cook food to at least 75 degrees Celsius
  • favourite temp is 37 degrees Celsius
  • Food temp can be tested by a food probe
• Moisture

  • Bacteria thrive in moist conditions
  • foods with high moisture content e.g chicken, meat and dairy products
  • Frozen foods - no moisture
  • Dried foods - most of moisture has been removed
  • Salted foods, pickles and jam - water unavailable as it has been replaced by vinegar, sugar and salt
• Suitable pH range

  • pH scale is used to determine how acidic or alkaline a substance is
  • acidic foods have a pH below 7
  • alkaline foods have a pH above 7
  • bacteria prefer neutral conditions (pH 7 )
• Food

  • bacteria need food to grow
  • High risk foods such as red meat, eggs, poultry, fish, milk and cooked rice are foods where bacteria are most likely to grow
  • these contain nutrients and moisture which bacteria use as a food source
  • can only be stored for a short time before they go off and become unsafe
• Time

  • Bacteria reproduce very quickly, dividing in 2 every 20 minutes
  • millions can be produced over 24 hours
  • After 2-3 hours food that contained few food poisoning bacteria will contain enough to cause illness
• Control Time

  • use by dates
  • if opened use within a certain amount of days
  • cool down leftover food quickly to get out of danger zone
  • store food correctly and for the correct length of time
• Cross Contamination 


  when bacteria are transferred from one product to another, in particular from raw to cooked foods e.g bacteria from hands onto cooked food

  • Avoid cross contamination by following the food safety guidelines when shopping, preparing, cooking, storing, serving and reheating food
• Food Poisoning Bacteria 


  Pregnant women, babies and older adults are more at risk of food poisoning bacteria as issues with immune system. Extra care must be taken to minimise risk of illness. Types of Food Poisoning Bacteria

  • Campylobacter
  • E-coli
  • Listeria
  • Salmonella
  • Staphylococcus Aureus
• Campylobacter

  • Symptoms - diarrhoea , stomach cramps, fever, vomiting
  • Food Sources - raw/undercooked meat, poultry, unpasteurised milk, untreated water
  • Control Method - prevent cross contamination, cook meat and poultry thoroughly, wash pre packed salad leaves
• E-coli

  • Symptoms - nausea, vomiting, diarrhoea, stomach cramps, severe anaemia, kidney failure
  • Food Sources - raw meat, undercooked mince beef, gravy, products made with unpasteurised milk, fish.
  • Control Method - prevent cross contamination, cook meat and poultry thoroughly and choose pasteurised milk and cheese
• Listeria

  • Symptoms - mild, flu like symptoms, nausea, diarrhoea, convulsions, blood poisoning, meningitis
  • Food Sources - unpasteurised cheese, soft, mould-ripened cheese, uncooked meat, cold cuts of meat, smoked salmon, pâte, ready meals and ready-to-eat foods
  • Control Method - cook meat and poultry thoroughly, wash raw veg, keep uncooked meats separate, choose pasteurised milk+cheese, prevent cross contamination, reheat ready made until piping hot
• Salmonella

  • Symptoms - fever, diarrhoea, vomiting, abdominal pain
  • Food sources - poultry, raw meat, eggs, unpasteurised milk, raw unwashed veg
  • Control Method - keep raw food away from cooked, ensure chicken, eggs and meats are cooked thoroughly until piping hot in centre above 63, always wash hands after handling raw meat and chicken
• Staphylococcus Aureus

  • Symptoms - severe vomiting, diarrhoea, abdominal pain
  • Food Sources - food made by hand that requires no cooking e.g sandwiches, and poultry, cooked meats, unpasteurised milk
  • Control Method - live on hands and nose, so high standards of personal hygiene are essential e.g wash hands after coughing, sneezing and keep food handling to a minimum
• Food Purchase - Do

  • observe the personal hygiene standards of staff handling and serving food
  • report unhygienic practices to store management or local EHO
  • check that chilled and frozen food cabinets are operating at correct temperature and not overloaded
  • buy chilled and frozen food last, pack together in an insulated bag/cool box
  • Get chilled and frozen foods home and stored appropriately ASAP
  • pack raw foods, fruit and veg away from cooked and ready to eat foods
• Food Purchase - Don’t

  • buy cans or packets of food that are damaged/opened
  • buy products from counters where raw and cooked foods are displayed and stored together
  • buy products that have exceeded use by/best before date
  • delay in storing chilled and frozen foods quickly and correctly
• food purchasing 


  make sure that food is as fresh as possible when it is bought and that it is stored safely to reduce risk of cross contamination and deterioration
• Food Storage


  Important part of reducing risk of food poisoning
• Storing food correctly


  1. Follow instructions

  2. Store in correct place

  3. Store at correct temperature

  4. Store for correct length of time
• Fresh foods that should be refrigerated


  • Dairy products
  • Fish
  • Meat
  • Ready meals
• Fridge temperature


  1. 4 degrees Celsius
• Important to follow additional instructions regarding how long food can be safely kept in fridge once opened
• Leftovers


  Stored in fridge, used within 2 days
• Storing food in freezer


  Extends shelf life as very low temperature means bacteria won't multiply
• Bacteria will reproduce once food defrosts, which is why thawed foods shouldn't be refrozen
• Storing food in freezer


  1. Carefully wrap

  2. Label
• Food not in fridge/freezer


  Should be stored in cool, dry area to maintain quality
• Storing food

  • Ready to eat foods on top shelf of fridge e.g yoghurt
  • Cooked meats and leftovers in middle shelf
  • raw meat, poultry and fish in bottom shelf in sealed containers
• Use by

  • Appears on labels of highly perishable or high risk foods
  • go off quickly and must be stored in fridge/freezer at correct temp
  • must be eaten by use by date
  • after food is unsafe and cause food poisoning
• Best Before

  • label of low risk foods that can be safely stored in cupboard
  • indicates how long food will be at its best
  • will remain safe to eat after date but quality will be affected
• Rules for using refrigerator

  • operate 1-4 - check with refrigerator thermometer
  • dont overload which prevents air from circulating
  • don’t open door more than necessary - lets warm air in which increases fridge temp and foots start to spoil
  • prevent cross contamination by storing foods in correct place
  • keep foods covered
  • don’t put hot food in the fridge as increases food temp
  • dont keep food beyond its date mark
• Safe use of the freezer

  • food should be carefully wrapped and labelled to avoid freezer burn
  • encourage sock rotation
  • read and follow freezer star rating system which shows how long food can be safely stored
• Star markings

  • no mark - stored in main component of fridge/freezer consume within 24 hours of purchase
  • * - frozen food storage compartment, consume within 1 week of purchase
  • ** - frozen food storage compartment, consume within 1 month of purchase
  • *** - frozen food storage compartment, consume within 3 months of purchase
• Personal Hygiene 


  When cooking, preparing and strong food:

  • wash hands regularly - before eating, after handling raw food, going to toilet, touching waste, handling pets
  • avoid handling if unwell/caring for ill person
  • cover cuts, sores and burns with clean dressings or blue plasters and change regularly
  • wear clean apron
  • remove jewellery
  • avoiding touching hair and tie long hair back
• Avoid preparing food for yourself for others if ill
• Do not reheat food more than once
• Food Prep and Cook

  • wash works surfaces and equipment in hot soapy water to ensure they are clean and do not have any bacteria on them
  • Washing up to air dry if possible as tea towels can have bacteria on them
  • Clean kitchen cloth and make sure to change regularly bleach and disinfect them
  • Empty and wash rubbish bins regularly
  • Keep the stock cupboard, refrigerator and freezer clean and checked that food is not out of date
• cooking food

  • Cook food thoroughly make sure food is cooked at least 75°C at the centre you can test this with a food temperature probe
  • Follow the instructions on the packaging carefully and always use suggested oven temperature and cooking time
  • Always cook poultry thoroughly
• reheating food

  • Cool food quickly if you want to reheat it later
  • Divide food into smaller portions and leave in a cold place to cool for up to 90 minutes and then refrigerate or freeze
  • Reheat food thoroughly by cooking to a temperature of at least 75°C for at least two minutes
  • Food reheated in a microwave oven should be after stand after cooking to help avoid cold spots developing in the food
  • Reheat food only once
• food poisoning


  Food poisoning is an illness caused by eating contaminated food

  Symptoms

  • Diarrhoea
  • vomiting
  • Stomach cramps
  • Abdominal pain
  • fever
  • flu-like symptoms
  • nausea
  • Loss of appetite

  Babies, young children elderly and people with illness are more risk as their immune systems are underdeveloped so it is harder to fight off bacteria