Safety glazing must be identified according to International Building Code (IBC), 2009, Section 2406.3. This applies to all glazing, not just tempered glass. Safety glazing can be plastic, laminated glass, or ceramic fire resistant glazing. Any glazing that meets the impact loads required by the code for hazardous locations, primarily doors and sidelights, can be considered safety glazing.
The IBC allows for two methods of marking safety glass. The first is to acid etch, sand blast, ceramic frit, laser etch, or emboss the glass with a permanent manufacturer's designation. This is the common marking found on tempered glass in one corner of the glass. The designation identifies the manufacturer and the standard to which the glass is manufactured.
The second method allows an applied label including the same information as the manufacturer's designation. The label must comply with the "Label" definition in Section 202.1. The labeling requirement does not include a specific method of marking the glass.
But what if the glazing is cut from large sheets by the opening fabricator as is common for plastic glazing? How will the glazing be marked when the product is out of the manufacturer's control?
There is an exception permitted for glazing materials other than tempered glass in Section 2406.3.1. If accepted by the building official, a certificate, affidavit or other evidence indicating compliance with the code may be permitted in lieu of identification on the glazing.
When relying on this exception, be sure the building official agrees to the exception, otherwise a designation or label will be required.