Sulphites are preservatives used extensively in the food and drink industry, and they are one of the 14 major allergens regulated under UK food law — declared and emphasised wherever they appear at concentrations above 10mg per kilogram or litre. Sulphite sensitivity is particularly prevalent in people with asthma, affecting an estimated 5–10% of asthma sufferers to a clinically significant degree.
What Sulphites Are and Why They're Used
Sulphites — including sulphur dioxide (SO₂), sodium sulphite, sodium metabisulphite, potassium metabisulphite, and related compounds — are preservatives that prevent oxidation (browning) and microbial growth in food and drink. They've been used for centuries, most famously in wine production, but now appear in a very wide range of products. Their effectiveness as preservatives and their low cost have made them ubiquitous in processed food manufacturing.
Where Sulphites Are Found
The most significant sources of dietary sulphites are wine and beer (where they're used extensively as preservatives — most wine contains between 30–150mg/L), dried fruits (particularly golden raisins, apricots, and other dried fruits that use sulphites to prevent browning — unsulphited versions are brown rather than orange or golden), pickled products, vinegar, many fruit juices and cordials, pre-prepared salads and vegetables (sulphites prevent cut vegetables from browning), processed meats and seafood products, and some pharmaceutical products and food supplements.
Importantly, sulphite concentration varies enormously between products. Dried apricots may contain over 2,000mg/kg — very high concentrations — while some products just above the 10mg/kg labelling threshold contain minimal amounts that may not trigger reactions in sensitive individuals.
Reactions and Symptoms
Sulphite reactions range from mild to severe and can include: bronchoconstriction (breathing tightening, particularly relevant for asthma sufferers), urticaria (hives) and skin flushing, headaches (the classic "red wine headache" has multiple causes, but sulphites contribute in sensitive individuals), gastrointestinal symptoms, and in severe cases anaphylaxis-like reactions. The mechanism differs from classic IgE-mediated allergy — sulphite reactions may involve histamine release, direct airway irritation, or other pathways — making standard allergy testing often unreliable for identifying sulphite sensitivity.
Managing Sulphite Sensitivity
Label reading is essential but insufficient, because sulphites may be present through processing even when not declared (below the 10mg/kg threshold). For people with significant sensitivity, some practical strategies: choosing organic wine (lower sulphite limits are permitted in organic wine production); buying unsulphited dried fruits (available from health food shops — they're darker in colour); avoiding packaged pre-cut salads and processed meat products; and being cautious with restaurant meals where sulphite use in preparation may not be disclosed. Asking specifically about sulphites when eating out with significant sensitivity is advisable.
Safe Food at Vanda's Kitchen
For people managing sulphite sensitivity, Vanda's Kitchen near St Paul's Cathedral EC4 provides a genuinely safe food option in the City of London. Our kitchen is 100% nut-free — no nut products of any kind are present in our facility — and we are certified halal. Every item we produce is fully allergen-labelled with all 14 mandatory UK allergens, in compliance with Natasha's Law. Our 5-star food hygiene rating confirms independent verification of our food safety standards.
For corporate catering where allergen management is a priority, our approach eliminates the cross-contamination risks that make "allergen-friendly" claims from mixed kitchens unreliable. Read our complete guide for the full detail on our allergen management standards.
For related reading, see our posts on histamine intolerance guide and the 14 UK food allergens. For corporate catering enquiries, WhatsApp us or send an enquiry.
Safe, Inclusive Food From Vanda's Kitchen
For Londoners managing food allergies and intolerances, Vanda's Kitchen near St Paul's Cathedral EC4 provides a genuinely safe food environment in the heart of the City. Our kitchen is 100% nut-free — no peanuts or tree nuts enter our facility under any circumstances — and our food is certified halal by the independently verified Halal Friendly List. Every item is labelled with full allergen information covering all 14 mandatory UK allergens, in compliance with Natasha's Law.
Our 5-star food hygiene rating confirms that our food safety practices are independently assessed and verified. Our Selfridges Food Hall presence confirms that our food quality meets the standards of one of London's most demanding food retail environments. For people managing serious food allergies, this combination of safety and quality is rare in the London food market. Visit us in EC4, order corporate delivery via our team lunch page, or WhatsApp us to discuss your requirements. Read our allergy-friendly catering guide for more.
Why London Professionals Choose Vanda's Kitchen
Whether you are managing dietary requirements for a team, looking for a nutritious daily lunch, or sourcing catering for a corporate event, Vanda's Kitchen near St Paul's Cathedral EC4 provides a consistent answer. Our kitchen is 100% nut-free as a permanent standard — no exceptions, no special requests needed. We are independently certified halal through the Halal Friendly List. We hold a 5-star food hygiene rating and our products are stocked in Selfridges Food Hall.
Our food is freshly prepared daily from our EC4 kitchen, rooted in Filipino culinary tradition and designed to deliver both nutritional quality and genuine flavour. For corporate lunch delivery, team catering, and event food across London, we offer a complete solution with the allergen credentials, dietary certifications, and food quality that London's most demanding clients require. View our team lunch options, WhatsApp us, or send an enquiry — we respond the same day.