Food safe ceramics and glazes is a complex subject. On this topic glaze technologists, toxicologists, artists, craftsmen, industrialists, lawyers and legislators meet. And I’m sure I’ve forgotten a few more. It’s also a subject I’m dealing with. Not as a glaze technologist, but as a craft entrepreneur.

A well-balanced glaze is not only durable, it is also safe for everyday use. As is my functional pottery, in EU jargon FCMs (Food Container Materials).

This means that my ceramics/glazes comply with the current EU directive ‘ceramic articles intended to come into contact with foodstuffs’. But these EU laws may soon be tightened.

What are the consequences for me and other artisan potters in Europe? I had an interview about this last week by two researchers on behalf of the European Commission for Health and Food Safety.

Current guidelines on food safe ceramics

Food safe ceramics is wide subject of great importance. Because not only must our food be safe, but also the material in which it is transported, stored, prepared and consumed. This can be ceramics, but also plastic, rubber, metal, wood etc. Legal guidelines have therefore been developed all over the world to ensure this.

Within the EU, these laws are laid down in the Directive “Food Container Materials“. EU Member States have incorporated these guidelines into local legislation. These are not only the same in all European countries, but also similar to, for example, guidelines in the US. So it’s more or less a world standard.

In the Netherlands, the Dutch Food and Consumer Product Safety Authority (NVWA) monitors compliance. In the event of an incident, they take action. Recently, for example, they advised that dishware made of bamboo with melamine plastic should no longer be used.

Researchers in the EU had determined that toxic substances from this material could get into food and drink. The bamboo cups and bowls in question had therefore been withdrawn from the shops immediately.

Ceramics traditionally trusted for food safety

Ceramics ar one of the oldest ways to store, prepare and eat food. A lot of knowledge has been gathered about this material in recent centuries. There have been therefor no recent incidents. But that was not always the case.

In the 1970s there was a stir about lead release of certain (traditional earthenware) pottery. In the early 1980s, this led to regulation in the EU but also in the US and other countries.

Current EU Specific Migration Limits (SMLs)

EU food safety initiative for ceramics

The regulations drawn up at the time are still used. That is not to say that there have been no developments in recent years. Food safety is high on the EU agenda. Hence the establishment of the European Food Safety Authority (EFSA) in 2002. They conduct independent research and advise the EU (Member States) on, among other things, food safe ceramics.

The Member States carry out their own checks, such as the NVWA in the Netherlands. In 2013, for example, they conducted a study on Tagines. This showed that (almost) all products complied with the current guidelines.

However, this report is already speculating on the arrival of new set of directives within the EU. The researchers therefore also tested for other metals and new limits. They carefully conclude that the current products would not comply with (possible) new rules.

These new ‘metal migration limits‘ have now been further developed in Europe. The initiative “Food safety – heavy metals in ceramics, glass and enameled table and kitchenware” is in its final phase as of 2021.

Reliable tests and laboratories

In 2017, the Joint Research Centre (JRC), part of the EU Science Hub, conducted research into test protocols and methods of “metal migration from ceramics and glass crystal tableware”. The conventional test regimen with acetic acid at 22 °C (room temperature) for 24 hours was still sufficient for ceramic dinnerware.

The Inductively Coupled Plasma Mass Spectrometry (ICP MS) test method is recommended to accurately measure the new tiny limit values. Mass spectrometrie is a technique used for the identification, quantification and profiling of isotopes, molecules and molecular complexes in very small quantities of chemical mixtures.

In addition, the European Union Reference Laboratory for Food Contact Materials (EURL-FCM) has conducted comparative research into laboratories in the EU that can carry out such tests. The JRC “Inter-laboratory comparison” reports on this comparison. According to the researchers, results were satisfactory. The success rate was higher than 80% for (almost) all elements tested.

Impact on ceramic production

In 2019, stakeholders were invited to respond to the EU’s plans. During this feedback period 39 organisations and citizens within the EU responded .

Geographically, Germans and Italians in particular have made their voices heard. Perhaps unsurprisingly, because a lot of (fine) ceramics are produced there.

The ceramic industry stressed the importance of clear and well-defined limits, but they are concerned about the possibilities and costs of ICP-MS testing by (approved) laboratories.

In addition, they feared that these new limits would remove almost 50% of all ceramic colour pigments from the market.

Moreover, some companies express concern that the proposed level is hardly feasible for artisanal and traditional ceramics. According to them, artisanal potters should be given an exceptional position in addition to sufficient transitional time.

Craft pottery in EU under pressure?

Because of this criticism, the European Commission (DG SANTE) has launched another study. The purpose is to better map the impact of these (possible) new rules on traditional and craft pottery.

This research is now carried out by the research agencies VVA and ICF. This year they are interviewing specific “Artisinal Manufacturers of ceramic, glass, crystal or enamelled metal” in the EU. And I was one of the “artisan ceramics entrepreneurs“.

I had already looked at the development of this regulation at an appropriate distance. Because of this interview by two VVA researchers, I dived a little further into it.

Information documents were also included in my invitation. Including the specific migration limits (SMLs) of the metals concerned.

Proposed EU Specific Migration Limits (SMLs)

“Liner glaze”, a glaze without limits

In my opinion, the proposed SML’s (migration limits) of the aforementioned metals are no more difficult to implement for craft potters than in industry. By far the easiest way is the use of a “liner glaze”.

This is a glaze for the “inside” of the ceramic. The part that comes into contact with food or drink. This glaze must then be composed without the relevant metal (oxides).

And fortunately, you can. There are plenty of possibilities to develop stable glazes without lead, cadmium, barium, cobalt and chromium. It is therefore quite possible to guarantee the food safe ceramics and glaze this way.

N.B. Arsenic is (almost) only used in the production of glass and I therefore leave it out. Also the toxic hexavalent chromium or Cr(VI) , is never used in ceramics. By chromium I mean the harmless or low toxic Cr(III) used in ceramic glazes.

No glaze without aluminium

For aluminium, however, that’s a different story. It is impossible to make ceramics without aluminum. Not that there is metal in ceramics, but clay and glazes are an aluminium silicate. That is, aluminum chemically bound with silicon (and oxides).

Aluminium is the third most common element in our earth’s crust, not pure but always as a mineral such as clay. That is very different from the (pure) metal aluminum, such as in aluminum foil and (camping) pans. Unbound aluminium will therefore not leak/migrate from clay or glaze.

Why a SML is proposed for aluminium is a mystery to me. For aluminum pans I understand this, but for ceramics? Do I also have to miss my weekly clay mask in the beauty salon? (No, as long as it is pure clay, it is absolutely safe, also by EU standards.)

But seriously, I don’t think the proposed limit is a problem for ceramic products. But proving that the limit is not exceeded is more difficult. This can only be done in a laboratory with the required equipment.

Protect craft pottery

For the other metals you can stay on the safe side by using a “liner” glaze. After all, with a glaze without metals for which an SML applies, it is impossible to exceed the proposed standard. This means that the inside of ceramics will be devoid of coloring oxides such as cobalt blue.

The alternative is to develop a stable glaze including the regulated metals. For barium and chromium oxide [III] (Cr) this is probably possible. The proposed limits are at a level that can be avoided. With cobalt and nickel, this is likely to become more difficult because the boundaries are very low.

However, the real problem is testing. The proposed test method (ICP-MS) can only be performed in a laboratory.

The ceramics industry fears that this is too expensive and unavailable for them. Then it is completely impossible for artisanal (small) producers like me.

How do I deal with the new rules?

I would like to have my glazes tested so that I can prove that my functional pottery is (minimally) in accordance with legal requirements. But if this is practically and financially impossible, I will have to consider whether I will continue to make bowls and cups (for sale).

For artisan ceramists who make traditional pottery with lead glaze, this is even more true. My knowledge in this area falls short of being able to say whether the proposed lead limits will be realistic for them. But if it is possible to develop such a glaze, then this can only be determined with tests.

Compliance with new rules, because of new insights, is always important to me. Whether it’s COVID-19 or new SML’s for food safe ceramics. Testing is always important for public health.

Make laboratory testing free

I’m happy to comply with new regulations. If the EU (and the Member States) truly stand up for our food safety and culture, help artisanal potters keep their products safe by offering free laboratory testing.

If craft potters/small business owners can voluntarily send their work for testing, the EU will gain insight into the food safety of ceramics made in this sector.

The potters are thus assured that their products always meet the latest requirements and the future of the craft is assured. And finally, everyone can continue to enjoy our rich diverse ceramics culture in Europe.

I say: win-win-win!

More information:

There is much more to be said about food safe ceramics and the new EU regulations. Not to mention the proposed labeling of functional pottery, but this blog is already too long 🙂

For anyone who wants to dive further into this subject matter, I have listed the information I used below:

Publications:

• “Metals and alloys used in food contact materials and articles“, Council of Europe (EDQM), 2013
• “Towards suitable tests for the migration of metals from ceramic and crystal tableware“, EU (JRC), 2017
• “Report on the inter-laboratory comparison exercise organised by the European Union Reference Laboratory for Food Contact Materials“, EU (JRC), 2017
• “Non-harmonised food contact materials in the EU: regulatory and market situation“, EU (JRC), 2016
• “Market research migration lead and cadmium from tajines“, Ministry of Lnv (NVWA), 2013

Websites:

• Food safety – heavy metals in ceramic, glass and enameled table and kitchenware, European Union (EC)
• Initiative on ceramic and vitreous FCMs, European Union (EC)
• Food Contact Materials, European Union (EC)
• FCM Document Library, European Union (EC)
• RIVM: Voedselcontact materialen, Dutch Ministry of Health, Welfare and Sport

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About Post Author

Daniel Bende

Designs and creates under the trade name DFB-ceramics hand-thrown stoneware figurative ceramics.

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