Food Safety & Hygiene
in the Catering Industry
A complete working reference on foodborne illness, allergen management, food handler duties, HACCP, hazard categories, cleaning, and the science of controlling bacterial growth in commercial kitchens — with worked examples at every step.
Common Foodborne Illnesses
Foodborne illness (food poisoning) occurs when a person consumes food or water contaminated with harmful bacteria, viruses, parasites, or their toxins. Below are the pathogens most frequently implicated in catering-related outbreaks, their typical onset, symptoms, and primary sources.
Salmonella
Symptoms: diarrhoea, fever, abdominal cramps, vomiting, headache. Lasts 4–7 days.
Primary sources: raw/undercooked poultry & eggs, unpasteurised milk, contaminated produce.
Example: a banquet egg mayonnaise left unrefrigerated for 5 hours sickened 40 guests — the eggs were fine at delivery, the hold time was the failure.
E. coli (STEC/O157)
Symptoms: severe stomach cramps, bloody diarrhoea, vomiting; can progress to kidney failure (HUS) in vulnerable groups.
Primary sources: undercooked ground beef, raw milk, contaminated leafy greens, faecal cross-contamination.
Example: a burger patty cooked to a pink centre because the cook judged doneness “by eye” instead of probing to 75°C.
Listeria monocytogenes
Symptoms: fever, muscle aches, sometimes nausea/diarrhoea; can cause miscarriage, sepsis, meningitis in high-risk groups.
Primary sources: chilled ready-to-eat foods, soft cheeses, deli meats, pâté — grows even in the fridge.
Example: pre-sliced deli meat kept two weeks past open-date in a fridge running at 8°C instead of 5°C.
Norovirus
Symptoms: sudden vomiting, watery diarrhoea, stomach cramps, low fever. Highly infectious person-to-person.
Primary sources: infected food handlers, shellfish, contaminated surfaces & ready-to-eat food.
Example: a handler came to work with an upset stomach “because it wasn’t that bad” and passed it to colleagues via shared tongs.
Campylobacter
Symptoms: diarrhoea (often bloody), cramping, fever, nausea; rare complication Guillain-Barré syndrome.
Primary sources: raw/undercooked poultry, unpasteurised milk, contaminated water.
Example: raw chicken juice dripped onto a salad shelf below it in an unsealed fridge.
Bacillus cereus
Symptoms: two forms — rapid vomiting, or later diarrhoea & cramps, both usually mild and self-limiting.
Primary sources: cooked rice/pasta left at room temperature, starchy foods reheated improperly.
Example: a pot of rice cooked in the morning and left on the counter until dinner — this is the classic “fried rice syndrome” case.
Clostridium perfringens
Symptoms: watery diarrhoea and cramps, usually without fever or vomiting; resolves within 24 hours.
Primary sources: large batches of meat, stews or gravies cooled too slowly after cooking.
Example: a deep stockpot of mutton curry cooling on the counter overnight instead of being portioned into shallow trays.
Staphylococcus aureus
Symptoms: sudden vomiting, nausea, cramps; toxin is heat-stable so re-cooking doesn’t destroy it.
Primary sources: food handled by hand after cooking — sandwiches, sliced meats, salads, cream-filled pastries.
Example: sandwiches hand-assembled by a handler with an infected cut on their finger, no glove worn.
Allergic Reaction Symptoms
A food allergy is an immune system response, distinct from illness caused by bacteria. Reactions can range from mild irritation to a life-threatening emergency and can appear within minutes of contact.
The 14 major allergens (India & international reference)
Reaction severity spectrum
Food Handler Responsibilities
Every person who prepares, cooks, or serves food carries legal and ethical responsibility for protecting the people they feed. These duties form the first line of defence against contamination.
Personal hygieneWash hands thoroughly before handling food, after using the toilet, touching raw meat, waste, or your face/hair, and at regular intervals throughout a shift.
Protective clothingWear clean uniforms, aprons, hair restraints, and where appropriate gloves — changed when soiled or when switching between raw and ready-to-eat tasks.
Reporting illnessReport symptoms such as diarrhoea, vomiting, fever, or infected wounds to a supervisor before starting work — do not handle food while symptomatic or for 48 hours after symptoms clear.
Preventing cross-contaminationUse colour-coded boards/knives, separate raw and cooked storage, and clean/sanitise surfaces between tasks.
Correct temperature controlCook, hold, cool, and store food at the correct temperatures, and check with a calibrated probe thermometer, not by sight.
Stock rotation & labellingFollow FIFO (First In, First Out), label opened items with dates, and discard food past its use-by date.
Allergen communicationKnow the allergen content of every dish and communicate it clearly to guests and colleagues, especially when a guest asks directly.
Cleaning & pest controlFollow the cleaning schedule, report pest sightings immediately, and keep waste areas covered and away from food prep.
Training & complianceComplete mandatory food hygiene training (e.g. FSSAI FoSTaC in India, Level 2 Food Hygiene elsewhere) and keep certification current.
What is HACCP?
HACCP stands for Hazard Analysis and Critical Control Point — a systematic, preventive approach to food safety that identifies where hazards could occur in a food process and puts controls in place before a problem happens, rather than relying on inspecting the finished product. It is the internationally recognised foundation of food safety management systems (including ISO 22000 and India’s FSSAI licensing requirements).
The 7 Principles of HACCP
Conduct a Hazard Analysis
Identify biological, chemical, physical, and allergenic hazards at every step of the food process, from delivery to service, and assess their likelihood and severity.
Determine Critical Control Points (CCPs)
Pinpoint the exact steps where control must be applied to prevent, eliminate, or reduce a hazard to a safe level — e.g. the cooking step for raw chicken.
Establish Critical Limits
Set measurable boundaries for each CCP — such as a minimum core cooking temperature of 75°C — that separate safe from unsafe.
Establish Monitoring Procedures
Define how and how often each CCP will be checked — e.g. probing every batch of chicken with a calibrated thermometer and logging the reading.
Establish Corrective Actions
Decide in advance what happens when a critical limit is not met — e.g. continue cooking, or reject and discard the batch.
Establish Verification Procedures
Confirm the whole system is working as intended — through internal audits, calibration checks, and review of monitoring records.
Establish Record-Keeping & Documentation
Maintain logs of hazards, limits, monitoring results, and corrective actions — the paper trail that proves the system is being followed.
Worked example: a chicken curry, step by step
| Step | Hazard example | Control |
|---|---|---|
| Delivery | Chicken delivered above 5°C | Reject delivery, check every batch |
| Storage | Raw meat stored above cooked food | Store raw on lowest shelf, separate fridges |
| Preparation | Cross-contamination via boards | Colour-coded boards, hand hygiene |
| Cooking (CCP) | Undercooked centre of chicken | Probe to confirm 75°C core temperature |
| Holding | Bacterial growth in the danger zone | Hold hot food above 63°C |
| Service | Extended time at room temperature | Limit display time to 2–4 hours max |
Food Safety Hazard Categories
Every risk in a kitchen falls into one of four categories. Recognising which type you’re dealing with determines the right control measure.
🦠 Biological hazards
- Bacteria (Salmonella, E. coli, Listeria)
- Viruses (Norovirus, Hepatitis A)
- Parasites (Giardia, Cryptosporidium)
- Mould & naturally-occurring toxins
🧪 Chemical hazards
- Cleaning chemicals & sanitisers
- Pesticide residues
- Food additives used incorrectly
- Toxic metals from damaged equipment
🔩 Physical hazards
- Glass, metal fragments, plastic
- Hair, jewellery, fingernails
- Bone fragments, stones, pest droppings
- Packaging fragments
🥜 Allergenic hazards
- Undeclared allergen ingredients
- Cross-contact between dishes
- Shared fryer oil or equipment
- Incorrect menu labelling
Controlling Bacterial Growth
Bacteria multiply fastest under specific conditions. Controlling these conditions — rather than trying to eliminate bacteria entirely — is the practical core of everyday food safety.
The Temperature Danger Zone
FAT TOM — the six conditions bacteria need to grow
Practical control methods
Cooking
Cook food to a minimum core temperature of 75°C (or equivalent time/temperature combination) to destroy vegetative bacteria.
Example: a whole tandoori chicken probed at the thickest part of the thigh, not just the surface.
Cooling
Cool cooked food from 63°C to below 5°C within 2 hours (ideally 90 minutes) using shallow trays, blast chillers, or ice baths.
Example: splitting a large dal batch into shallow 5cm-deep trays instead of one deep pot, so heat escapes faster.
Chilling
Store perishables at or below 5°C; check fridge temperatures at the start and end of every shift and log them.
Example: a walk-in fridge thermometer checked and logged at 8am and 8pm on a wall-mounted sheet.
Hot holding
Keep hot food at or above 63°C in bain-maries or heated cabinets; never let it drift into the danger zone during service.
Example: a buffet chafing dish topped up with fresh hot food rather than being left to slowly cool over 3 hours.
Reheating
Reheat food to a core temperature of at least 75°C, and only reheat once — repeated reheating multiplies risk.
Example: leftover gravy reheated once to 75°C for the next service, then any remainder is discarded, not reheated again.
Freezing
Store at -18°C or below to make bacteria dormant; label with freeze date and defrost safely in a fridge, not on a countertop.
Example: frozen prawns defrosted overnight in a covered container on the bottom fridge shelf, not in a sink of warm water.
Cleaning & Sanitising
Cleaning removes visible dirt and grease; sanitising reduces the invisible bacteria left behind. A surface that looks spotless can still be carrying enough bacteria to cause illness — both steps are needed, in the right order.
The 6-stage cleaning process
Pre-clean
Scrape or wipe away loose food debris before applying any chemical, so detergent works on the surface, not on food scraps.
Main clean
Apply hot water and detergent to break down grease and remove remaining dirt from all surfaces and equipment.
Rinse
Rinse away detergent and loosened dirt with clean hot water — leftover detergent can interfere with sanitiser.
Sanitise
Apply a food-safe sanitiser at the correct concentration and contact time to destroy remaining bacteria.
Final rinse (if required)
Some sanitisers need rinsing after their contact time; check the product label — others are designed to air-dry in place.
Air dry
Let items air dry on a rack rather than wiping with a cloth, which can reintroduce bacteria onto a just-sanitised surface.
Chemical safety basics
Storage
Keep chemicals in a designated area away from food, in original labelled containers — never decant into unlabelled bottles.
Dilution
Follow manufacturer dilution ratios exactly; stronger isn’t safer, and under-diluted sanitiser may not reach the required contact time.
COSHH / MSDS
Keep safety data sheets accessible for every chemical used, and train staff on what to do if there’s accidental contact or ingestion.
Quick Shift Revision Checklist
A fast recap of the non-negotiables covered above — useful as a pre-shift reminder or a last-minute revision pass.
Use the search bar above to jump straight to any term — danger zone, allergen, CCP, or otherwise.