Cross contamination: the rules, controls and UK law

What is cross contamination?

Cross contamination is when harmful bacteria, viruses or allergens pass onto food from other food, surfaces, hands or equipment. GOV.UK's own definition is shorter: "Cross-contamination is when bacteria is spread between food, surfaces or equipment" (GOV.UK, avoiding cross-contamination in your food business, updated 30 June 2026). The Safer Food Better Business pack widens that to allergens and calls it "one of the most common causes of food poisoning".

In a kitchen, it usually means bacteria from raw food ending up on food that won't be cooked again. Raw chicken juice on a salad board. A knife used on raw beef, wiped and then used on cooked ham. A chef handles raw mince, then plates a dessert. Cooking would have killed the bacteria on the raw food. Nothing kills them once they're on the ready-to-eat food.

This page covers what the law requires in each UK nation, the controls inspectors look for, the colour-coding question, allergen cross-contact, E. coli O157 and what happens when businesses get it wrong.

Cross contamination at a glance

• Raw food touching or dripping onto ready-to-eat food is the main risk; see the four routes below.
• No UK law requires colour-coded boards; the FSA says dedicated kit is essential only without heat disinfection.
• Complex equipment like vac packers and slicers can't be shared unless fully dismantled and disinfected.
• Gloves and hand gels don't replace handwashing, and raw meat and poultry shouldn't be washed.
• Allergens spread the same way, and cooking doesn't remove them.

Why it matters: raw food, ready-to-eat food and low doses

The guidance splits food into two groups.

• Raw food needs cooking or washing before it's safe. SFBB lists "raw meats & unwashed salad, vegetables and fruits".
• Ready-to-eat food won't be cooked again before it's eaten: "cooked foods, washed salads, garnishes, desserts and other foods that will not be cooked before eating" (SFBB separating foods).

GOV.UK says the harmful kind "is most likely to happen when raw food touches or drips onto ready-to-eat food, utensils or surfaces". The risk is greatest with E. coli O157, which the Food Standards Agency (FSA) says "can cause infections in very low doses - less than 10 bacteria" (FSA E. coli O157 cross-contamination guidance). It also survives the fridge and the freezer. At that dose, a smear you can't see is enough. Cooking won't save the salad.

The four routes, and the control for each

The table below is how we'd map routes to controls for a typical pub or restaurant kitchen. The controls come from the FSA and Food Standards Scotland (FSS) guidance cited throughout this page.

Allergens follow the same four routes. We cover them in their own section below because the controls work a bit differently.

What does the law require?

There's no single "cross-contamination law". The duty comes from the retained EU hygiene regulation, read with each nation's own regulations.

Regulation (EC) No 852/2004. Annex II, Chapter IX, paragraph 3 says that at every stage, "food is to be protected against any contamination likely to render the food unfit for human consumption, injurious to health or contaminated in such a way that it would be unreasonable to expect it to be consumed in that state" (Annex II). Other chapters in Annex II cover premises layout, equipment, washing facilities and cleaning. Article 5 requires a food safety management system based on HACCP, and cross-contamination is one of the hazards it has to control (Article 5).

The offence in each nation. Breaking those EU rules is a criminal offence under:

• England: Food Safety and Hygiene (England) Regulations 2013, regulation 19
• Wales: Food Hygiene (Wales) Regulations 2006, regulation 17
• Scotland: Food Hygiene (Scotland) Regulations 2006, regulation 17
• Northern Ireland: Food Hygiene Regulations (Northern Ireland) 2006, regulation 17

The guidance. The law doesn't say "use a red board for raw meat". It tells you the outcome and leaves the method to you. The guidance fills in the method:

• England, Wales and Northern Ireland: the FSA's E. coli O157 cross-contamination guidance (published 23 January 2024) and GOV.UK's short page on avoiding cross-contamination. Your SFBB pack is where you write your own controls down.
• Scotland: FSS publishes its own E. coli O157 control of cross contamination guidance (published 28 November 2017) and the CookSafe manual instead of SFBB. It tells businesses that "A food business operator should undertake a risk assessment on site". The controls are much the same as the FSA's.

For how these rules sit under the Food Safety Act 1990, see our food law explainer. For the management system itself, see HACCP explained.

Separation: what the guidance expects

The FSA ranks the ways of keeping raw and ready-to-eat food apart. "The options in order of effectiveness are":

1. A permanent separate room for raw food, with its own storage, staff, equipment, utensils and sinks.
2. A permanent "clean area" for ready-to-eat food, big enough and far enough from raw work that splashes can't reach it.
3. A "temporary clean area" that is separated by time, cleaned and disinfected between uses.

Most small kitchens use option 3. If you do, the FSA wants it planned: "all ready-to-eat food should be prepared first and either served for immediate consumption or chilled/stored", then the area is used for raw meat, then cleaned and disinfected again.

Where you share space, the FSA lists what to split or mark as raw or ready-to-eat. That includes fridges, utensils, sinks, wash hand basins, and even "cling film, wrapping (and dispensers), vac bags, sanitiser, cloths".

Storage

GOV.UK's rule is short: "store raw food below ready-to-eat food in the fridge". The FSA guidance adds the exception: raw food "must be stored below ready-to-eat food unless other measures are in place to ensure that cross-contamination is avoided". The ideal is separate fridges. If you share one, SFBB says raw meat, poultry, fish and eggs go at the bottom. Unwashed fruit and vegetables go above raw meat and away from ready-to-eat food. For the temperatures, see our fridge temperature check guide.

Watch for two storage problems.

• Defrosting. SFBB warns that the liquid from defrosting raw food "can contain harmful bacteria". Defrost covered, in the fridge, below ready-to-eat food.
• Clean kit stored in a raw area. The FSA says equipment and wrapping for ready-to-eat food must not be stored "underneath a worktop where preparation of raw food is undertaken".

Complex equipment

Vacuum packers, slicers, mincers, blenders and mixers "are not to be dual used unless the equipment is fully dismantled and disinfected between uses". Bacteria get into internal parts that routine cleaning doesn't reach.

In practice, that means one vac packer or slicer for raw and another for cooked. Label them. If a supplier sells "vac-packed" cooked meats, ask how they handle this. FSS uses almost the same wording ("unless the equipment is fully dismantled and disinfected between uses"), and CookSafe calls dual use of complex equipment "particularly dangerous".

Sinks

Don't wash ready-to-eat food in a sink used for raw food unless it has been cleaned and disinfected. Even then, the FSA says ready-to-eat food "must not come into direct contact with the sink"; use a dedicated container. The FSA recommends separate sinks where you can manage it.

Colour-coded chopping boards: are they a legal requirement?

No. We found no UK law that requires colour coding, or any particular colours. The FSA calls dedicated equipment good practice. It says businesses should have separate knives, containers and chopping boards for raw and ready-to-eat food, and "these should be easily identifiable, for example, colour coded". It also says: "Where heat disinfection or dishwasher cleaning is not available this is essential."

The legal duty is to keep raw and ready-to-eat equipment apart, and colour is one way to show you do. If you have a commercial dishwasher that can heat disinfect, GOV.UK says you can use the same equipment, as long as it goes through that cycle between raw and ready-to-eat use. If you don't, you need dedicated, clearly marked kit.

The usual UK scheme is:

Some caterers add purple for allergen-free food. This is an industry convention, not something the FSA sets. Some competitor guides describe it as "recommended by the FSA and CIEH" or say "the convention is UK-wide; adopt it as written". We couldn't find either claim in the FSA's guidance. Keith Warren of the catering equipment suppliers' association CESA told The Staff Canteen: "it is not a regulation that you have to use a particular colour with a particular food product" (The Staff Canteen).

But sticking to the standard colours still helps. New staff arrive knowing them, and a red board used for cooked chicken is a mistake waiting to happen. Whatever scheme you use, write it in your SFBB or HACCP plan and put a chart on the wall.

Also replace worn boards. The FSA says "Chopping boards that have deep scores from repeated use should be replaced as effective cleaning may no longer be possible."

Cleaning and disinfection

Separation only works if the cleaning between uses works. The FSA guidance asks for:

• A two-stage clean: clean off the dirt first, then disinfect. Disinfectant doesn't work on a dirty surface. Our two-stage cleaning page covers the method.
• Products that meet "BS EN 1276:2009 or BS EN 13697:2001 or equivalent standards". It's on the label or the data sheet.
• The right dilution and contact time. The guidance warns disinfectants "will not be effective if used on dirty surfaces, or if applied at the incorrect dilution or for the insufficient contact time".
• Heat disinfection, such as a commercial dishwasher cycle, as the alternative to chemicals for utensils and boards.

Cloths. CookSafe says cloths "must be kept clean" and suggests single-use cloths for "light switches, door handles and telephones". A reused cloth wiped across a raw-meat bench and then a serving counter spreads bacteria across the whole kitchen.

Touch points. GOV.UK names "door handles, bins, tills and touch screen electronics". The FSA says shared items like "pens, phones, chip and pin machines and light switches" can be shared by raw and ready-to-eat staff. If they are, "Staff must wash their hands before handling any ready-to-eat food and after handling raw food. This is the main control."

Hands, gloves and gels

For hands, the rule is to wash after touching raw food, bins, money or your phone, and before touching ready-to-eat food. CookSafe sets out the steps: wet your hands, apply liquid soap, rub palm to palm, the backs of the hands and between the fingers, then rinse and dry "with a single use towel".

The FSA guidance is firm on gloves and gels.

• Gloves. "Gloves are not a substitute for effective handwashing." Change them as often as you'd wash your hands, wash before putting them on, and change any that tear. And one pair of gloves worn from the raw-chicken prep to the salad station is no better than not washing at all.
• Hand gels. The FSA says they "do not remove visible dirt and are not to be used as a replacement for handwashing". Use them after washing if you like, never instead of it.

Don't wash raw meat or poultry

Plenty of cooks were taught to rinse chicken. Don't. SFBB says plainly "Do not wash raw meat or poultry" because washing "does not kill bacteria", and it "can splash harmful bacteria around the kitchen contaminating sinks". GOV.UK lists "not washing raw meat, fish and poultry" as one of its controls. Cooking does the job.

Allergen cross-contact

Allergens spread the same way. When one gets into a dish that should be free of it, the result for someone with a severe allergy can be fatal. Many allergen specialists call this "cross-contact", because cooking doesn't remove an allergen the way it kills bacteria.

The routes are the same: shared fryer oil, a spoon moved from the satay to the stir-fry, flour dust settling in the open, a board that held bread and then cheese for a gluten-free order. The controls are:

• Prepare allergen-free food separately "where possible" and store it separately (SFBB).
• Use dedicated or freshly cleaned equipment. Cleaning removes allergen traces. Heat doesn't.
• Wash hands and change aprons between tasks.
• Keep the allergen information for each dish accurate, and update it when a recipe or supplier changes.

"May contain" labels. If you pre-pack food for sale, the FSA's precautionary allergen labelling guidance says a label like "may contain x" "should only be used when, following a risk assessment, a risk of allergen cross-contact within the supply chain is identified that cannot be removed through risk management actions". Blanket wording such as "may contain allergens" "could be deemed misleading". And you can't put "may contain milk" on something you also call "free-from milk".

For training your team, see our allergen management guide.

Physical and chemical contamination

SFBB also covers the other two kinds of contamination. Physical contamination is anything that ends up in food by accident: glass, metal, plastic, hair, plasters. That's why SFBB asks for cuts to be covered with "a brightly coloured waterproof dressing". Chemical contamination means things like "cleaning products or pest control chemicals". SFBB says to store cleaning chemicals "separately from food", label them clearly and follow the manufacturer's instructions. They're separate hazards from bacterial cross-contamination, but your HACCP plan needs to cover all three.

E. coli O157: the case for strict separation

The FSA says E. coli O157 "mostly live in the intestines of animals", and because animals live in fields, soil can carry it too. That puts it on raw meat and on unwashed vegetables. The dose is tiny, and the FSA says "special care" is needed where young children or the elderly are the main customers, such as schools and care homes. That's why the guidance is stricter on complex equipment and separation than general hygiene advice. CookSafe says staff with E. coli O157 need "formal exclusion and then medical clearance" before they go back to handling food.

If you sell raw and ready-to-eat food from the same counter, as many butchers, delis and farm shops do, read the full FSA (or FSS) guidance. For staff training, see our E. coli control training guide.

Penalties and enforcement

Cross-contamination offences fall under the same per-nation food hygiene regulations as other hygiene breaches.

Prosecution is usually the last step. Officers can serve a hygiene improvement notice, which gives "not less than 14 days" to put things right (regulation 6). Where there's an imminent risk to health, they can close a business straight away with a hygiene emergency prohibition notice (regulation 8). Wales, Scotland and NI have matching powers. Cross-contamination also counts against your score. It's one of the hygiene practices behind your food hygiene rating. For what an inspection looks like, see what an environmental health officer does.

Real cases

Langshott Manor, Horley (2025). Utopia Leisure Ltd, which runs the hotel, was found guilty on 13 August 2025 of offences including failing to train and supervise food handlers and failing to comply with a hygiene improvement notice. Reigate and Banstead Borough Council's officers had found that "a designated raw meat surface was being used to prepare and store ready to eat/cooked foods", alongside poor cleaning, food kept past its use-by date and food handlers not trained in allergen systems. The court fined the company £80,000 plus £21,000 costs (Reigate and Banstead Borough Council).

Palm by H2O, Coventry (2025). In June 2024, 29 people became ill after eating at the restaurant, some needing hospital treatment. The UK Health Security Agency (UKHSA) confirmed 17 of 18 stool samples carried the same Salmonella strain. Inspectors found raw meat stored above cooked food, no evidence of proper handwashing and a lack of training. The company was fined £10,000 and its director £6,500, each with £10,186.55 costs and a £2,000 victim surcharge (Coventry Observer). Council food safety officers told the BBC: "Given the absence of measures in place to prevent cross-contamination in the kitchen ... this is unfortunately unsurprising."

White Hart, Cullompton (2020). Mid Devon District Council prosecuted The White Hart At Cullompton Ltd, sentenced on 27 February 2020, after finding "filthy wiping cloths on worktops used in food preparation". Swabs of the cloths found E. coli and Enterobacteriaceae. The fine and costs came to £6,700 (Mid Devon District Council).

How to check your kitchen in ten minutes

Walk the kitchen with this list at opening:

1. Fridges: raw food at the bottom, covered and labelled; nothing defrosting on an open shelf.
2. Boards and knives: right colour (or right label) at each station; no deep scores.
3. Complex equipment: slicer and vac packer marked raw or cooked, and used that way.
4. Sinks: soap, hot water and paper towels at every wash hand basin.
5. Cloths: fresh or single-use; none left on a raw bench.
6. Sanitiser: in date, to BS EN 1276 or 13697, at the right dilution.
7. Allergen-free station and containers set up; allergen chart current.
8. Touch points (doors, tills, phones) on today's cleaning schedule.

Record it. If you're ever inspected after a complaint, a dated record of these checks is part of showing you took reasonable precautions. You can run the same list as a digital checklist in Pilla, with photos and a sign-off at each station.

Common myths

"Colour-coded boards are a legal requirement." Not in UK law. Separation is the requirement; colour is the usual way to show it. Without dishwasher heat disinfection, the FSA says dedicated equipment is "essential".

"Gloves mean you don't need to wash your hands." The FSA says the opposite: "Gloves are not a substitute for effective handwashing."

"Hand gel does the same job." It doesn't replace washing with soap and water.

"Washing chicken makes it safer." It spreads bacteria round the sink. Cook it properly instead.

"A good wipe is enough for the slicer." Not for complex equipment used for raw and cooked food. It has to be fully dismantled and disinfected, or kept for one use only.

"Cooking kills allergens." It doesn't. Allergen control relies on separation and cleaning.

FAQ

What is cross contamination in food?

It's when harmful bacteria, viruses or allergens spread onto food from other food, surfaces, hands or equipment. The most dangerous kind is when bacteria from raw food reach food that won't be cooked again.

What are the main types of cross contamination?

Food to food (raw meat dripping onto cooked food), surfaces and equipment (shared boards, knives or slicers), hands, and indirect touch points like door handles, tills and cloths. Allergens spread by the same routes. Physical and chemical contamination are related hazards.

Is colour coding chopping boards a legal requirement in the UK?

No. The law requires food to be protected from contamination. The FSA calls dedicated, identifiable equipment good practice, and says it's essential if you can't heat disinfect it in a dishwasher. Colour coding is the usual way to do it.

Where should raw meat go in the fridge?

At the bottom, covered, below ready-to-eat food. Ideally use a separate fridge for raw meat.

Can I use the same vacuum packer for raw and cooked food?

Only if it's fully dismantled and disinfected between uses, which few kitchens can manage. The FSA says complex equipment should not be dual used otherwise.

Do gloves prevent cross contamination?

Only if they're changed as often as you'd wash your hands. The FSA says gloves are not a substitute for handwashing.

What is allergen cross-contact?

It's when an allergen gets into food that should be free from it, for example through a shared fryer, utensil or board. Cooking doesn't remove allergens, so separation and cleaning are the controls.

What is the penalty for cross contamination?

It's a food hygiene offence. In England and Wales the fine in the magistrates' court is unlimited, and on indictment there can be up to two years' prison. Councils can also serve improvement notices or close a business that poses an imminent risk.