Sulphur Dioxide E220
Sulphur Dioxide, also written as sulfur dioxide or SO2, is a food-grade preservative and antioxidant used in approved food and beverage applications for microbial stability, yeast inhibition, mould control, oxidation management, enzymatic browning control and shelf-life protection. It is particularly important in wine, dried fruit, fruit processing, juices and selected industrial systems where sulphite performance, residual level control and regulatory labeling are critical. This page is prepared for purchasing teams, R&D technologists, QA departments, plant managers and import teams that need structured technical information before requesting a quotation.
Product identity
| Product name | Sulphur Dioxide |
|---|---|
| Alternative spelling | Sulfur Dioxide |
| Common abbreviation | SO2 |
| Chemical formula | SO2 |
| CAS number | 7446-09-5 |
| E / INS number | E220 / INS 220 |
| Category | Preservatives & Antimicrobials |
| Primary function | Preservative, antioxidant, anti-browning agent and antimicrobial shelf-life support |
| Typical supply form | Liquefied gas, compressed gas, controlled dosing system or sulphiting system depending on supplier and application |
| Related additives | Sodium sulphite, sodium bisulphite, sodium metabisulphite, potassium metabisulphite and other sulphite salts |
Application fit
Sulphur Dioxide is evaluated where oxidation control, colour protection and microbial inhibition are required under approved regulatory conditions. Potential use areas may include:
- Wine, cider, fruit wine and fermentation control systems
- Dried fruits, dehydrated vegetables and colour-sensitive fruit products
- Fruit juices, concentrates, syrups and fruit preparations where permitted
- Potato products, peeled produce and enzymatic browning control systems
- Sugar processing, starch processing or selected industrial ingredient systems
- Processing environments where validated sulphiting control is legally permitted
Technical overview for industrial buyers
Sulphur Dioxide is a highly functional preservative because it can contribute both antimicrobial and antioxidant effects. In food and beverage systems, it may exist in different chemical forms depending on pH, water activity, temperature and product composition. The balance between molecular SO2, bisulphite and sulphite species influences antimicrobial activity, binding behavior and residual measurable sulphite levels. For this reason, finished-product pH and analytical control are central to the successful use of Sulphur Dioxide and sulphite-based preservation systems.
Industrial buyers should evaluate Sulphur Dioxide by food-grade suitability, assay or purity, impurity profile, moisture or contaminant status where relevant, packaging or cylinder compliance, valve compatibility, supplier traceability, transport classification, safety documentation and regulatory support. Unlike many dry food additives, Sulphur Dioxide may require specialized storage, trained handling, controlled dosing equipment, gas detection, ventilation and emergency procedures. The commercial decision should therefore consider total system safety and operational capability, not only ingredient price.
Functional role in formulation
- Antimicrobial preservation: helps inhibit yeasts, moulds and selected bacteria in suitable acidic systems.
- Antioxidant protection: reduces oxidative quality loss in wines, juices, fruits and oxygen-sensitive products.
- Anti-browning effect: helps control enzymatic browning in selected fruit and vegetable applications.
- Fermentation management: supports microbial control in wine and fermentation systems when used under controlled conditions.
- Colour retention: helps protect light-colored dried fruits and other colour-sensitive products where permitted.
- Process protection: can reduce quality deterioration during processing, holding, storage and distribution.
Key buying parameters
| Grade | Food grade; confirm suitability for intended application and destination-market rules |
|---|---|
| Assay / purity | Request declared SO2 purity and test method on specification and COA |
| Impurity profile | Review moisture, acidity, residues or market-specific contaminants where applicable |
| Supply format | Compressed gas, liquefied gas, cylinder, bulk system or approved sulphiting alternative |
| Container compliance | Check cylinder certification, valve type, fill weight, pressure rating and return conditions |
| Dosing compatibility | Confirm compatibility with plant dosing, metering, injection and safety systems |
| Transport classification | Requires review of dangerous goods documentation and local transport restrictions |
| Documentation | COA, SDS, food-grade declaration, transport documents and destination-market declarations |
Industrial application notes
In wine and fermentation systems, Sulphur Dioxide is used to support microbial control, protect aroma and flavour quality, reduce oxidation and manage fermentation risk. Winemakers and industrial beverage producers monitor free SO2, bound SO2 and total SO2, because only part of the total sulphite content is available for antimicrobial and antioxidant function. Product pH has a major influence on molecular SO2 availability, so dosage strategies must be based on analysis rather than fixed assumptions.
In dried fruit and fruit processing, Sulphur Dioxide is valued for colour protection and mould control. It can help maintain the characteristic appearance of dried apricots, raisins, apples and other dried products where its use is permitted. However, residual sulphite levels, uniformity of treatment, worker safety, product labeling and customer specifications must be carefully managed. Excessive or uneven treatment can cause sensory defects, regulatory non-compliance or rejection by customers.
In juices, concentrates, syrups and fruit preparations, Sulphur Dioxide or sulphite systems may be evaluated for antioxidant protection and microbial control. Finished product pH, oxygen pickup, heat process, packaging format, storage temperature, metal ions, ascorbic acid level and raw-material microbiology all influence performance. Manufacturers should validate residual levels at production, after processing and during shelf-life testing.
For peeled produce, potato products and other browning-sensitive systems, sulphite treatment can slow enzymatic browning where permitted. Industrial use must consider dipping concentration, contact time, drainage, residual SO2, worker exposure, wastewater handling and final product declaration. Because regulations vary widely, the buyer should confirm both process legality and finished-product labeling before commercial use.
Preservation system design
- Define the target function: antimicrobial control, antioxidant protection, browning control or fermentation management.
- Measure finished-product pH and evaluate free, bound and total SO2 where relevant.
- Confirm legal maximum levels for the food category and destination country.
- Validate the addition point, mixing intensity, contact time and residual level after processing.
- Evaluate compatibility with ascorbic acid, oxygen exposure, metal ions, packaging and heat treatment.
- Perform shelf-life testing or challenge testing when changing supplier, process or dosage.
Process and handling considerations
- Use only trained personnel and approved dosing equipment for gas or sulphiting systems.
- Provide ventilation, gas detection and emergency response procedures in storage and dosing areas.
- Keep cylinders or containers secured, labeled and protected from heat or mechanical damage.
- Confirm valve, regulator, hose and gasket compatibility with SO2 service.
- Prevent uncontrolled release, inhalation exposure, cross-contamination and unauthorized handling.
- Maintain batch records linking raw material lot, dose, analytical result and finished product release.
Quality control checkpoints
Food manufacturers typically evaluate Sulphur Dioxide through both supplier documentation and in-process analytical control. Because SO2 can bind with sugars, aldehydes, pigments and other food components, the practical preservative effect may differ from the amount added. Finished product testing is therefore essential, especially for products with regulatory limits, export documentation requirements or sensitive consumer labeling requirements.
Supplier and raw material checks
- Food-grade declaration and product identity confirmation
- Assay or purity as SO2
- Impurity and contaminant profile according to specification
- Certificate of analysis linked to shipment or cylinder batch
- Cylinder or container inspection, fill weight and valve condition
- Safety data sheet and dangerous goods documentation
- Lot number, filling date, retest date and traceability information
- Supplier approval, audit status and change-control expectations
Finished product checks
- Free SO2, bound SO2 and total SO2 where applicable
- Residual sulphite level against legal and customer limits
- pH, acidity and oxidation-reduction behavior
- Microbial stability during shelf-life testing
- Colour retention and browning control performance
- Sensory review for sulphurous off-note or over-treatment
- Label declaration and allergen statement verification
- Batch record review before finished goods release
Regulatory and compliance notes
Sulphur Dioxide is commonly identified as E220 or INS 220 and belongs to the wider sulphite additive group. Permitted food categories, maximum residual levels, analytical methods, additive names, allergen declarations and warning statements can differ by country and product type. In many markets, sulphites require special declaration when present above defined thresholds, even when used as processing aids or when residual levels remain in the finished product.
Buyers should distinguish between Sulphur Dioxide E220 and related sulphite salts such as sodium sulphite, sodium hydrogen sulphite, sodium metabisulphite, potassium metabisulphite and calcium sulphite. These materials are not identical from a sourcing, handling or labeling perspective. If a formulation, customer specification or regulation refers to total SO2, the buyer should confirm whether limits are expressed as sulphur dioxide equivalent and how analytical results must be reported.
Recommended documents to request
- Product specification or technical data sheet with assay, purity and impurity parameters
- Certificate of analysis for available batch, cylinder lot or shipment lot
- Safety data sheet with handling, exposure, emergency and storage information
- Food-grade declaration and statement of intended food use
- Origin statement and manufacturer or filling-site information where available
- Transport classification, dangerous goods declaration and cylinder documentation where applicable
- Allergen or sulphite declaration support for finished product labeling review
- Heavy metals or market-specific contaminant compliance where required
- Shelf-life, retest, storage and cylinder-return information
- Label draft, net content, cylinder size, valve type, pallet or crate configuration and loading estimate
- Traceability information, batch coding format and recall-support documentation
Specification information useful for quotation
For a faster and more accurate quotation, provide the product name, intended application, required grade, annual and first-order quantity, destination country, delivery term, preferred supply format, storage capability, required certifications, inspection requirements, expected shipment date and document list. If you already purchase Sulphur Dioxide or related sulphite products, share the current specification, COA, label declaration, cylinder format, dosing system details or benchmark supplier information so equivalent options can be compared by purity, packaging, documentation, safety requirements and logistics cost.
Packaging and logistics
Sulphur Dioxide is usually quoted according to supply form, cylinder or container size, net fill, returnability, pallet or crate format, port of loading, Incoterms, destination regulations and dangerous goods transport requirements. Export shipments require careful review of SDS, transport documentation, cylinder certification, customs rules, storage permissions and local receiving capability. For some buyers, related sulphite salts may be more practical than direct SO2 gas handling, depending on application and regulation.
Commercial evaluation criteria
- Food-grade status and documentation completeness
- Assay, purity, impurity profile and batch traceability
- Suitability for wine, fruit, dried fruit, juice, produce or process application
- Compatibility with buyer’s dosing, safety and analytical control systems
- Availability of transport, cylinder and dangerous goods documentation
- Lead time, stock position, minimum order quantity and cylinder return terms
- Regulatory fit for the destination market and final food category
- Total landed and operational cost, not only unit price
How to request this product
Send the product name, intended food application, target grade, required assay, quantity, destination country, supply format, packaging or cylinder preference, expected shipment date and required documents. If the product will be used in wine, dried fruit, fruit juice, fruit preparations, potato products, peeled produce or fermentation control, include the target residual SO2 level, finished product pH, local legal limit and any allergen-labeling requirement so the supplier review can focus on the most relevant technical and regulatory parameters.
Useful answers
What is Sulphur Dioxide used for in food manufacturing?
Sulphur Dioxide is used as a preservative, antioxidant and anti-browning agent in approved applications. It supports microbial stability, yeast inhibition, mould control, oxidation management and colour protection in products such as wine, dried fruits, fruit preparations, juices and selected processing systems.
Is Sulphur Dioxide the same as sulphites?
Sulphur Dioxide is E220 and belongs to the broader sulphite family. Sulphite salts such as sodium metabisulphite or potassium metabisulphite can contribute sulphur dioxide in food systems, but they differ in identity, handling, dosing, labeling and regulatory treatment.
Why does pH matter for Sulphur Dioxide performance?
pH affects the balance between molecular SO2, bisulphite and sulphite forms. In many acidic food and beverage systems, this balance influences antimicrobial activity, antioxidant effect, binding behavior and residual sulphite measurement.
Why is sulphite labeling important?
Sulphur Dioxide and sulphites may require special declaration when present above market-defined thresholds. Buyers should verify final product residual levels, label wording and destination-market requirements before commercial use.
Which grade should food manufacturers request?
Food manufacturers should request food-grade Sulphur Dioxide with a clear specification, certificate of analysis, safety data sheet, food-use declaration, impurity limits, transport documentation, packaging details and destination-market compliance documents.
Can Global Food Additives source Sulphur Dioxide?
Global Food Additives can review sourcing options for Sulphur Dioxide according to target specification, application, quantity, destination, supply format, safety documentation, certification needs and required export documents.
Which documents should be requested?
Buyers commonly request a technical data sheet, certificate of analysis, safety data sheet, food-grade declaration, origin statement, sulphite declaration support, transport documents, cylinder information, shelf-life or retest information, label details and packing configuration.
Is this product permitted in every country?
No. Food additive use depends on destination-market rules, food category, use level, residual sulphite limits, label requirements and buyer responsibility. Always verify local regulations before commercial use.
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Send product names, target specifications, quantity, destination country, packaging preference, delivery term, and document requirements. Our team will review your inquiry and respond from orders@foodgradeadditives.com.
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