Food Safety and Using Bullseye Glass for Functional Pieces
Glass artists love creating bowls, plates, platters and serving pieces that are both beautiful and functional. When glass is intended to come into contact with food, it is important to understand a few safety considerations so that your finished work is suitable for everyday use.
If you work with Bullseye glass, you may have noticed that some colours contain small amounts of lead (Pb) or cadmium (Cd). These materials are commonly used in glass manufacturing to achieve specific colours and effects. While they are stable when properly fired, it is still important for artists to understand how they behave in food related applications.
This guide explains what artists should know when creating food bearing fused glass pieces.
Which Bullseye Glass Colours May Contain Lead or Cadmium
In the Bullseye catalogue, certain colours contain measurable levels of lead or cadmium. Generally, this includes glasses with more than 1.0% lead or more than 0.5% cadmium.
These materials are used to achieve some of the vibrant reds, oranges and yellows that glass artists love. They are considered safe within the glass matrix when fired correctly, but care should be taken when these glasses may come into contact with food.
Artists who plan to make plates, bowls or serving dishes should be aware of which colours fall into this category.
Clear Capping for Added Protection
A common technique used by kilnformers is clear capping. This involves placing a layer of clear Bullseye glass over the coloured glass before firing.
Clear capping acts as a barrier between the coloured glass and the food surface. Testing has shown that when these colours are capped with clear glass, the amount of lead or cadmium that can leach from the surface is extremely small and remains well below FDA limits.
For many artists, clear capping provides extra peace of mind when creating functional work.
Transparent vs Opalescent Glass
Bullseye testing has also shown that transparent glasses tend to release less lead or cadmium than opalescent glasses.
This means that in some cases, transparent colours may already have very low leaching levels even without clear capping. However, many artists still prefer to cap the surface if the piece will regularly hold food.
Surface Texture and Food Contact
Surface texture can also play a role in food safety.
Highly textured surfaces increase the total surface area that can come into contact with food. This can potentially increase the chance of leaching.
For this reason, artists often design their pieces so that the food contact side is smooth and fully fused, while decorative textures are placed on the outside of the piece.
Keeping the food surface smooth also makes cleaning easier.
Responsibility for Artists Selling Functional Glass
If you plan to sell functional glass objects such as plates or bowls, it is important to understand that the artist or maker is responsible for ensuring the finished piece meets food safety requirements.
Testing performed by glass manufacturers provides helpful guidance, but it does not cover every firing schedule, design variation or finishing technique.
Because of this, artists producing items for sale may choose to perform independent testing on their finished work to confirm that the piece is safe for food contact.
Decorative vs Functional Pieces
Some glass artworks are created purely for display, while others are designed for everyday use.
When deciding whether a piece should be used with food, consider the following:
Functional pieces often include
• Smooth food contact surfaces
• Clear capping where appropriate
• Stable firing schedules that fully fuse the glass
Decorative pieces may include
• Heavy texture or relief
• Uncapped colour layers
• Surface treatments intended for visual impact rather than food use
Clearly communicating whether a piece is decorative only or food safe can help customers understand how to use it properly.
Final Thoughts
Fused glass can be both artistic and functional, but understanding the materials you are working with is an important part of responsible craftsmanship.
By choosing appropriate colours, using clear capping where needed and maintaining smooth food contact surfaces, artists can create beautiful glass pieces that are both visually striking and suitable for practical use.
Read the Original Resource
This article summarises key points for artists. For the full technical guidelines and testing information, please refer to the original resource from Bullseye Glass.
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