What is a safety glass stamp (tempering stamp) and why is it important?

A safety glass stamp (tempering stamp) is a permanent marking that is applied to the glass during the production process. This is used for example with tempered glass, laminated safety glass, walkable glass, and tempered painted glass. The stamp is a ceramic marking that is baked into the glass, making it impossible to remove once applied.

What does a safety glass stamp indicate?

The stamp indicates that the glass complies with the European standard EN 12150-1. In many cases, the stamp includes:

• a statement that the glass is safety glass
• a reference to the standard (for example EN 12150-1)
• an identification of the manufacturer or supplier

This makes the glass traceable and recognizable as safety glass.

Why is a safety glass stamp important?

Without a stamp, it is not visible to users, installers or inspectors whether the glass is actually safety glass. In certain situations, this can lead to risks.

A stamp is particularly important for applications such as:

• shower doors and shower enclosures
• balustrades and partitions
• doors and glass at impact or walking height
• glass in public or industrial environments

What are the consequences of not using a safety glass stamp?

If safety glass does not have a stamp, this can result in:

• uncertainty about whether the glass is actually safety glass
• rejection during inspection or project handover
• discussions about liability in case of damage or injury

In case of damage or an incident, the absence of a stamp can make it difficult to prove that the glass complies with the required standards.

Is a safety glass stamp mandatory?

In many applications, adding a stamp is not explicitly mandatory, but it is strongly recommended. The stamp serves as proof that the glass has been manufactured in accordance with the correct standard.

In applications where safety plays an important role, it is therefore considered standard practice to include a stamp.

Where is the safety glass stamp placed?

The stamp is usually placed in a corner of the glass, so that it remains visible but as unobtrusive as possible. The exact position may vary depending on the product or application.

When would you choose not to include a safety glass stamp?

In some cases, it may be desirable not to include a stamp, for example for aesthetic reasons. The stamp is visible in the glass (usually in a corner), which may be considered undesirable in certain applications.

This mainly applies to:

• tempered mirrors or glass used in furniture (such as glass shelves)
• decorative applications or design objects (such as tabletops)
• picture frames or displays where the glass should appear completely “invisible”

It is important to understand that without a stamp it is not visually verifiable that the glass is safety glass. This may lead to uncertainty about the glass specifications during inspection, handover or in case of damage.

The decision not to include a stamp is therefore always the responsibility of the customer. For applications where safety, regulations or liability are important, it is strongly recommended to include a stamp.

Important: the stamp is permanent and cannot be changed afterwards

A stamp is applied during the production process and is therefore permanent. It is a ceramic marking baked into the glass and cannot be removed without damaging or replacing the glass.

The choice to include or exclude a stamp must be made at the time of ordering. Once the order has been placed, this choice cannot be changed, as the glass is then produced according to specification.

Please check carefully in advance whether you want a stamp, especially in applications where both appearance and safety are important.

Summary

A safety glass stamp is a small but important marking that confirms the glass complies with applicable safety standards. It provides clarity, traceability and helps prevent discussions or risks afterwards.