What Does "Sulphur Free" Mean?

On Xianyitang products labelled “Sulphur Free”, the sulphur dioxide and sulphite content, expressed as SO₂, is zero. This statement applies only to products carrying that label; it does not mean that all naturally occurring sulphur-containing compounds are absent. Check each product label for full ingredients and allergen information.

E-numbers are codes assigned to food additives approved for use in the UK. The E220–E228 group covers sulphur dioxide and its related sulphite salts. When reading a food label, you may see either the E-number or the full additive name — both refer to the same group of substances.

Sulphur dioxide and sulphites may be used in some foods as preservatives or antioxidants. They can help maintain appearance, reduce browning, extend shelf life and control microbial spoilage in certain food categories — including some dried fruits and vegetables.

Sulphur dioxide and sulphites may be used only in permitted food categories and within the applicable legal limits. Some consumers need to pay particular attention to sulphites; the references below provide further information. If you have a diagnosed intolerance or allergy, seek advice from a qualified healthcare professional.

Sulphur dioxide and sulphites are one of the 14 major allergens recognised under UK food labelling law. When present at more than 10 mg/kg or 10 mg/litre (calculated as total SO₂), they must be clearly declared on food labels — making it straightforward to identify products that contain them by reading the ingredients list.

When buying dried herbs, mushrooms, dried flowers or soup ingredients, check the ingredients list for any of the following:

The images below show how sulphite preservatives appear on real food product labels — written in full or as an E-number.

Xianyitang products labelled "Sulphur Free" are processed without added sulphur dioxide or sulphite preservatives. The wording reflects our production approach and internal QA/QC monitoring.

For products labelled “Sulphur Free”, sulphur dioxide residues are also monitored through in-house laboratory testing as part of internal QA/QC.

The manufacturer — Zhongshan Xianyitang Traditional Chinese Medicine Co., Ltd (中山市仙逸堂中药饮片有限公司) — operates its own in-house laboratory and QA/QC team. Sulphur dioxide residue is monitored in accordance with China's food safety national standard GB 5009.34—2022, "Determination of Sulphur Dioxide in Food" (食品中二氧化硫的测定).

GB 5009.34—2022 covers three recognised testing methods:

Some customers prefer sulphur-free ingredients because they wish to avoid added sulphur dioxide or sulphite preservatives in their cooking. Others choose them because they value simple ingredient lists, transparent labelling and batch-level quality monitoring.

This is a personal food choice, not a medical recommendation. Whatever the reason, we want customers to be able to make that choice with confidence — knowing that our "Sulphur Free" designation is backed by both production discipline and laboratory verification.

Sulphur dioxide and sulphites are regulated food additives permitted by law. Products containing them are widely consumed. The purpose of this page is not to suggest that sulphite-containing foods are unsafe — it is to help customers understand the terminology, know how to read a food label, and understand clearly what "Sulphur Free" means on Xianyitang products.