Hydrogen
A colourless, odourless gas used in food packaging to prevent oxidation and extend shelf life, and dissolved into some beverages.
What is it?
Hydrogen (H2) is the lightest and most abundant element, existing as a colourless, odourless, tasteless gas at room temperature. As a food additive, it is used in food-grade purity at a minimum of 99%.
What does it do?
In modified atmosphere packaging, hydrogen displaces or reduces oxygen inside sealed packaging, slowing fat oxidation and microbial spoilage. It can also be dissolved into beverages, where it acts as a reducing agent. In wine production it has been used to limit oxidation during fermentation. Because hydrogen molecules are extremely small, it has also been used in packaging quality assurance as a trace leak-detection gas.
Where you will see it
Hydrogen appears in packaging for fatty fish, meats, certain cheeses, and some beverages including juice and soft drinks. It has also been used in dietary supplements dissolved in water. On a UK label it may appear as E949 or as 'hydrogen' in the ingredients or packaging gas declaration.
What the science says
Toxicological assessment: how hydrogen behaves in the body
Hydrogen gas is characterised as non-toxic. Because it has very low solubility in water (approximately 1.62 mg per litre at 21 degrees Celsius), the amount that dissolves into food from packaging is very small. The EU Scientific Committee for Food evaluated hydrogen in 1990 and found no need to set an acceptable daily intake, concluding that its use as a packaging gas was toxicologically acceptable. A 2025 EFSA re-evaluation confirmed this, finding no safety concern from its use as a food additive.
The EU Scientific Committee for Food concluded in 1990 that hydrogen's use as a packaging gas is toxicologically acceptable and that no acceptable daily intake needed to be established.
The EFSA Panel on Food Additives and Flavourings concluded that the use of hydrogen (E 949) as a food additive does not raise a safety concern, based on very low dietary exposure and low toxicological concern.
Hydrogen in beverages: emerging research, limited evidence
There is growing interest in hydrogen-rich water as a functional beverage, with early research suggesting possible antioxidant and anti-inflammatory effects. A 2024 systematic review covering 31 human randomised controlled trials found preliminary evidence for effects on oxidative stress and metabolic markers. However, most studies involve small numbers of participants, short durations, and variable hydrogen doses, and no findings have yet been confirmed by large, long-term trials. The EFSA panel noted that hydrogen's possible therapeutic applications in food uses remain largely anecdotal.
A systematic review of 31 human randomised controlled trials found preliminary evidence that hydrogen-rich water may reduce oxidative stress markers and affect blood lipids, but studies were heterogeneous and sample sizes small.
A meta-analysis of 8 randomised controlled trials in metabolic disorders found small decreases in LDL cholesterol and triglycerides with hydrogen-rich water, but changes were not statistically significant.
EFSA noted that despite growing interest in hydrogen's therapeutic applications when used as a food additive, use remains largely anecdotal and exposure from food uses is very low.
Data gap: manufacturing impurities
The 2025 EFSA re-evaluation identified one notable limitation: no manufacturers submitted data on their production methods for food-grade hydrogen. This means the panel could not fully verify that existing specifications cover all potential impurities from every production route. Food-grade hydrogen must be at least 99% pure, and the panel found the listed impurities at that purity do not raise a concern, but the gap in manufacturing data was flagged as outstanding.
No business operators provided manufacturing process information, so EFSA could not fully assess whether specifications adequately covered all potential impurities from all production methods.
Where it stands with the regulators
Who should be careful
No group is required to avoid hydrogen as a food additive on current evidence. People with specific intolerances should look at other ingredients in the product, not the packaging gas itself.
The honest read
Hydrogen is one of the most unremarkable substances in the food additive list. It is a gas that dissipates quickly and has extremely low solubility, so very little actually enters the food. Food regulators in both the EU and UK have consistently found nothing to flag over 35 years of evaluation, and the most recent 2025 review reached the same conclusion. The one live question is not about the gas itself but about whether manufacturers have fully documented their production methods, which EFSA flagged as a data gap. There is also active scientific interest in hydrogen-rich water as a functional food ingredient, but the evidence from human trials is still early and the studies are small.
Related additives
Common questions
Is E949 banned in the UK?
No. Hydrogen (E949) is approved for use in the UK and EU under the assimilated EU Regulation 1333/2008 and appears on the UK FSA approved-additives list. It can be used at quantum satis levels across all food categories.
Does hydrogen in food packaging affect the food I eat?
Very little. Hydrogen has very low solubility in water (roughly 1.62 mg per litre at 21 degrees Celsius), so the amount that dissolves into food from packaging is minimal. It is colourless, odourless, and tasteless, and does not alter the food's flavour, appearance, or nutritional content.
What foods contain E949?
E949 appears in a small number of food products, including fatty fish, meats, certain cheeses, and some beverages such as juice, soft drinks, and hydrogen-infused water. It has also been found in some vitamin and dietary supplement products. It is not a common additive, appearing in fewer than 0.1% of food subcategory products in market surveys.
Is E949 vegan?
Yes. Hydrogen is an elemental gas with no animal-derived origin. It is suitable for vegans and vegetarians and carries no religious dietary restrictions.
Sources
- EFSA Panel on Food Additives and Flavourings: Re-evaluation of oxygen (E 948) and hydrogen (E 949) as food additives. EFSA Journal 2025;23(8):e9595
- EFSA Journal publication page: Re-evaluation of oxygen (E 948) and hydrogen (E 949) as food additives
- UK Food Standards Agency: Approved additives and E numbers
- EU Regulation 1333/2008 on food additives (EUR-Lex)
- Hydrogen Water: Extra Healthy or a Hoax? A Systematic Review. International Journal of Molecular Sciences, 2024
- The Effects of Hydrogen-Rich Water on Blood Lipid Profiles in Metabolic Disorders: A Systematic Review and Meta-analysis. PMC11742746
- Packaging with hydrogen gas modified atmosphere can extend chicken egg storage. PubMed 34302359
- Food-Info.net: E949 Hydrogen
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