Silver
Metallic silver used to give a shiny silver finish to confectionery, chocolates, and some liqueurs. Applied as powder or thin leaves.
E174 contains silver nanoparticles that have shown genotoxic signals and oxidative stress in intestinal cells in lab studies. EFSA twice could not confirm its safety, citing unresolved data gaps on nanoparticle toxicity and ionic silver release. An EU ban is under active consideration as of 2025.
What is it?
Elemental silver (chemical symbol Ag) in its metallic form, processed into fine powder or thin leaves. It is a natural metal obtained by mining and refining silver ore. The finished food additive contains a mix of microscale flakes and a large proportion of nanoscale particles.
What does it do?
Acts purely as a surface colourant. The metallic silver reflects light to produce a bright silver or grey metallic sheen on food surfaces. It provides no flavour or preservative function.
Where you will see it
Used to coat dragees and pralines, decorate chocolate confectionery, and colour some liqueurs and spirits. It is applied to the outside of products only. On a UK label it appears as 'silver' or 'E174' in the ingredients list.
What the science says
EFSA could not confirm safety in 2016 or 2025
EFSA reviewed E174 as part of its re-evaluation of all pre-2009 food additives. In 2016 the panel concluded the available data were insufficient to assess safety, citing unknown nanoparticle content and unanswered questions about ionic silver release. After a call for further data, only one company responded, and its submission still failed to address the critical gaps. EFSA's 2025 follow-up opinion reached the same conclusion: it could not confirm the safety of silver as a food additive.
The EFSA ANS Panel concluded in 2016 that the information available was insufficient to assess the safety of silver as a food additive, citing lack of adequate physicochemical characterisation and absence of data on ionic silver release.
In its 2025 follow-up, EFSA again could not conclude on the safety of E 174. Submitted genotoxicity studies used a non-validated assay and were deemed not reliable; subchronic toxicity data did not meet GLP standards; no data on ionic silver release were provided.
E174 contains a very high proportion of nanoparticles
Physical analysis of commercial E174 products and the confectionery made from them found that more than 97% of the silver particles by number were nanoscale, with a median size of around 11 to 18 nanometres. Despite the bulk mass being in larger flakes, the overwhelming majority of individual particles fall in the nanoparticle range. EFSA's guidance requires a separate nano-specific risk assessment for water-insoluble materials where over 10% of particles in at least one dimension fall below 250 nm, and E174 exceeds this threshold.
In pristine E174 additives and in finished confectionery products, nanoparticles represented more than 97% of silver particles by number, with a median minimum external dimension of 11 to 18 nm.
When E174-containing confectionery was introduced to water, over 97% of released particles by number were nanoparticles with an 11 nm median size, contradicting an industry operator's claim that only 10% of particles were nanoscale.
Genotoxicity signals in laboratory and animal studies
Lab and animal studies on silver nanoparticles have found DNA damage markers, oxidative stress, and disruption to intestinal cells. Studies submitted to EFSA in the 2025 review found concentration-dependent DNA damage signals (gamma-H2AX phosphorylation, a marker of DNA strand breaks) in human liver cells and colon tissue of mice. EFSA judged these studies unreliable because they used a non-validated assay not accepted by OECD guidelines, but the signals themselves were not absent. Separate independent research confirms that silver nanoparticles trigger reactive oxygen species and genotoxic effects in gut cell lines.
Silver nanoparticles caused concentration-dependent DNA damage marker expression (gamma-H2AX) in human liver cells in vitro and in mouse colon tissue after 90-day dietary exposure in an industry-submitted study. EFSA judged the assay not reliable for regulatory purposes.
Silver nanoparticles caused dose-dependent loss of intestinal cell viability, increased intracellular reactive oxygen species, DNA strand breaks, and altered mitochondrial dynamics in human intestinal epithelial cell models.
Silver nanoparticles from food-grade E174 induced cellular stress, altered cytokine expression, and mitochondrial disruption in intestinal epithelial cell lines.
Ionic silver release raises additional concerns
When metallic silver nanoparticles dissolve inside the body they can release silver ions (Ag+), which are more chemically reactive than the metal itself. EFSA identified ionic silver release as a key concern in 2016. By the 2025 review, no data on this had been submitted at all by industry, leaving the question entirely unanswered.
EFSA identified release of ionic silver from E174 particles as a major safety concern in 2016. No data on silver ion release were provided by the single industry operator who responded to the 2018 call for data, leaving the gap unaddressed in 2025.
Potential EU ban under active consideration
Following EFSA's 2025 conclusion that safety cannot be confirmed, the European Commission must now decide whether to withdraw authorisation for E174 across the EU. The situation closely mirrors the path taken with titanium dioxide (E171), which was banned as an EU food additive in 2022 after EFSA also could not establish its safety. The UK maintains E174 as authorised under assimilated EU law as of mid-2026, but has not independently reviewed it.
After EFSA's 2025 follow-up concluded safety could not be confirmed, the European Commission announced it would discuss E174's future at the next Working party of Governmental experts on Additives, with a ban under active consideration.
Titanium dioxide (E171) followed the same regulatory pathway: EFSA could not confirm safety, the EU banned it in 2022, and the UK followed. E174 is now on a comparable trajectory.
Where it stands with the regulators
Who should be careful
Anyone wishing to avoid an additive whose safety has not been confirmed by regulators should check ingredient labels for 'silver' or 'E174'. The additive appears on the outside surface of dragees, chocolate decorations, and some liqueurs. There is no specific declared-allergen requirement for silver under UK food law.
The honest read
E174 sits in an unusual position: it is still legally permitted in UK and EU food, yet the scientific regulator responsible for assessing it has twice, nine years apart, said it cannot confirm it is safe. That gap between legal status and scientific opinion reflects the slow pace of regulatory action, not a clean bill of health. The core unresolved questions are whether the nanoparticles that make up over 97% of E174 particles by number cause DNA damage or cellular harm in the gut at real exposure levels, and what happens when those particles release ionic silver inside the body. Lab studies show concerning signals. The industry submitted data intended to close those gaps; EFSA judged the studies inadequate. The picture is unresolved, not cleared.
Related additives
Common questions
Is E174 banned in the UK?
No, E174 is still authorised in the UK under assimilated EU law as of mid-2026. However, the EU is actively considering a ban after EFSA concluded in 2025 that the safety of silver as a food additive cannot be confirmed. The UK has not carried out an independent post-Brexit review of E174.
Why has EFSA not been able to confirm E174 is safe?
EFSA identified three critical gaps that industry has not filled: adequate physicochemical characterisation of the nanoparticles in E174, genotoxicity data from validated, OECD-accepted studies, and data on how much ionic silver is released from the particles inside the body. Without this data, EFSA cannot complete the risk assessment.
What foods contain E174?
E174 is used to decorate confectionery such as dragees (the small hard-coated sugar or chocolate sweets), pralines, and chocolates, and to colour some liqueurs and spirits. It appears on the surface of products only. It will be listed as 'silver' or 'E174' in the ingredients.
Is E174 vegan?
Yes. E174 is metallic silver, a mineral with no animal-derived ingredients. It is suitable for vegans and vegetarians, and carries no religious dietary restrictions.
Sources
- EFSA Scientific Opinion on the re-evaluation of silver (E 174) as a food additive (2016)
- Follow-up of the re-evaluation of silver (E 174) as a food additive, EFSA Journal 2025 (PMC open access)
- UK FSA Approved Additives and E Numbers
- UK FSA Authorised Regulated Food and Feed Products: E174
- Physico-chemical characterisation of silver (nano)particles in food additive E174 and in E174-containing confectionery, Food Additives and Contaminants: Part A 2020
- Physicochemical Transformations of Silver Nanoparticles in the Oro-Gastrointestinal Tract and Toxicity to Intestinal Cells, PMC 2023
- No Silver Lining: E174 Ban? Food Law Consult, April 2025
- RIVM: EFSA's re-evaluation of silver as a food additive is inconclusive
- EU Consolidated Regulation (EC) No 1333/2008 on food additives
See this on every food you scan
NutraSafe reads the label and puts every additive into plain English, with the source, right in the app.
Get NutraSafe on the App Store