In a shared production building, the operator next door is rarely the risk. The risk sits in the things you share with them: the goods-in bay, the cold store, the corridor, the wash-up, the bins. Separation is a question about touchpoints, and the answer decides which claims you can put on your label and which buyers will sign.
For a manufacturer looking at production space, one objection usually comes up first. We make a peanut-free product, or a halal range, or something for a kosher customer. How can we produce that in a building with other manufacturers’ food?
The answer is that separation in shared production is mostly about the building, not the neighbours. So before you sign for any space, you should understand exactly where the shared surfaces are.
Why separation is a commercial question
UK law requires 14 allergens to be declared whenever they’re used as an ingredient or processing aid. Undeclared allergens make food unsafe in law, not just in practice. For most manufacturers, though, the pressure arrives through the buyer rather than the regulator. A retailer, wholesaler or contract caterer will want to see your allergen risk assessment. If you make a free-from or certified religious claim, they’ll want to know how the claim survives your production environment.
That’s where separation becomes commercial. A claim is only as strong as the route your product takes through the building. If that route can’t be defended, you lose the claim.
The label is the output of the building
The clearest way to see this is through precautionary allergen labelling, the familiar “may contain” statement. The Food Standards Agency’s guidance is specific. A “may contain” statement should only be applied after a risk assessment, where cross-contact is a genuine risk you haven’t been able to control. It should name the specific allergen, so “may contain peanuts” rather than “may contain nuts”. And it should never sit alongside a free-from claim for the same allergen, because a free-from claim is a guarantee, and it requires strict controls that eliminate the risk.
Read that as a manufacturer and the implication is direct. A blanket “may contain” is not a safe default. It’s an admission that your environment couldn’t be controlled, and it narrows your market. A space where you can’t evidence control at every shared point effectively writes that statement for you. A space where you can lets you make the claim, and defend it to an auditor.
Where cross-contact actually happens
In a building of self-contained production units, the unit itself is the easy part. Your walls, your equipment, your team and your cleaning regime are yours. The risk lives at the points where your product, your people or your waste touch something someone else also touches.
Goods-in is the first. Deliveries arrive on shared pallets and in outer packaging that has sat in other people’s vans and warehouses. If they’re unpacked in a shared bay, or travel through the building still in their delivery packaging, that’s a route for cross-contact before production has even started.
Shared cold storage is the second. Raw materials and finished goods from several operators in one walk-in is workable for many products. For a free-from or certified range it’s a serious weakness, because storage is precisely where the FSA expects allergenic ingredients to be kept apart.
Movement through the building comes next: the corridors, lifts and doors that raw materials, finished product and staff all pass through. If raw goods and ready-to-eat product cross paths, or your team walks through someone else’s space to reach their own, the flow is doing the opposite of what an auditor wants to see.
Wash-up and waste are the two most often forgotten. A shared pot wash means your utensils are cleaned in the same place as someone else’s. A shared refuse route means your waste and someone else’s finished product may meet in a corridor.
Air is the least obvious. Flour and other powdered allergens travel, and where extraction and ventilation serve more than one space, airborne transfer is a real consideration. It’s one reason extraction belongs on any manufacturer’s checklist, as we set out in what extraction, power and drainage decide about a unit.
None of these are reasons to avoid shared production. They’re the list of things a good shared site should either design out or show you are properly controlled.
Allergen control inside your own unit
Inside the unit, allergen management looks much as it would in a facility you built yourself. The FSA points operators towards separate storage, production areas and utensils where possible. It also points to cleaning validated at every point of cross-contact. Where one line handles several products, it recommends producing from least to most allergenic so the riskiest run comes last. Colour-coded equipment, dedicated containers and documented changeover cleans turn that into something an auditor can follow.
What a shared site changes is how much of this you have to build. If the unit is self-contained, with its own wash-up and a one-way flow, your allergen work is about procedure and documentation, which is where it should be. If it isn’t, you’re either compensating with procedure for a gap in the building, or applying a “may contain” you’d rather not use. Our piece on what “audit-ready” means under SALSA and BRCGS covers why certification judges the whole operation, not just the production room. Allergen control is the sharpest example of that principle.
Halal and kosher: a different kind of separation
Religious certification is sometimes treated as allergen management with different ingredients. It isn’t, and the difference matters when you’re choosing space.
Allergen control is about traces: a safety question measured in cross-contact risk. Halal and kosher certification is about status. A product either meets the certifying body’s requirements or it doesn’t. Those requirements cover ingredients, equipment, cleaning, storage and sometimes who may handle the product.
Halal certification is the clearest example. The two most prominent UK bodies, the Halal Food Authority and the Halal Monitoring Committee, apply requirements that differ from each other. That’s the first thing to understand: there isn’t one halal standard to design to, and the certifier your customer accepts sets the rules. The HFA’s audits look at ingredients, recipes, and the hygiene and segregation of production equipment on site. Halal certification of a shared facility is generally possible, but only where the business can demonstrate effective cleaning, segregation, storage and traceability.
Kosher certification follows a similar logic with its own requirements. These include supervision by the certifying authority, separation of meat and dairy production, and specific rules on how equipment may be used and prepared.
The practical consequence is the same for both. The certifier will look at your building, not just your unit. They’ll want to know where non-certified materials are stored, what equipment is shared, and how the route through the building is controlled. Ask your certifier what they need from a shared site before you commit to one. Then ask the provider whether they can give it to you.
What it looks like in practice
Borough 22 shows how demanding separation can get. The bakery makes gluten-free, plant-based doughnuts and bakes. Today, most of its range is free from all 14 major allergens, it’s kosher-certified, and it’s described as halal-friendly. Each product carries several claims at once, and each depends on a different control. Gluten, egg, milk, nuts and sesame all have to stay out of the room, and every claim has to hold up for the building as well as the recipe.
Borough 22 produced from a standard unit at our Bermondsey site for around 18 months, from November 2023 to May 2025. We made no special adaptations for them. When the production space is self-contained and the shared touchpoints are already designed out, a demanding free-from operation doesn’t need a bespoke build. It needs the right standard.
“The facilities are top-notch, impeccably clean, and well-equipped with everything you need to run a smooth and efficient food production… It’s the perfect place for growing food brands that need a reliable and professional setup.”
Sourav Sharma, Head of Operations, Borough 22
That standard is the same in every unit, at every site. Every operator produces in its own self-contained unit, so the production space, equipment and team are never shared. Where a stricter certification calls for more, we have built it for other clients, from separate changing facilities to separate ventilation and dedicated cold stores.
What we don’t do is certify you. Your allergen risk assessment, your HACCP plan and your relationship with your certifier are yours. What we can do is make sure the building gives you every chance of passing.
What to ask before you sign
The useful questions for any shared production space follow the touchpoints above:
- Is goods-in shared, and is outer packaging removed before materials enter production?
- Is cold storage shared, or can you have your own?
- Does the flow through your unit run one way, so raw materials and finished product never cross?
- Do you have your own wash-up, or share one?
- How does waste leave, and does it cross the path of finished goods?
- What does the extraction serve?
- Has the provider housed a free-from, halal or kosher operator before, and can they tell you what that operator needed?
A provider that can answer those quickly and specifically has thought about separation. One that answers in generalities hasn’t, and you’ll be the one explaining the gaps to your auditor.
The short version
Separation in shared production is decided by touchpoints, not neighbours. A shared building can support an allergen-free claim or a religious certification if every point where your product meets something shared is either designed out or provably controlled. Work out which touchpoints your claim depends on, ask your certifier what they need, and choose a space that can give you both.
Producing allergen-controlled, halal or kosher products, or about to? Talk to us about what your separation requires →
