It is a requirement for all Master Glaziers to be members of the Window & Glass Association New Zealand
Below is the Window & Glass Association New Zealand statement on safety glass...

VALIDATING SAFETY GLASS

Toughened safety glass is normally marked with ceramic ink fused into the glass in the toughening furnace. The manufacturing processes are governed by 'S' Mark or ISO 9000 quality assurance compliance procedures.
Laminated safety glass is permanently etch-marked with chemicals or sandblasting with the label information at the time it is cut from a panel of safety glass.
NZS 4223:Part3:1999 requires safety glass to be tested and to comply with AS/NZS2208, or similar. Third party audited quality assurance markings, such as the 'S' mark, will ensure that these products have been produced by reputable manufacturers. Do not accept other glass manufacturing standards without checking their validity for the application.

RANDOM TESTING OF UNMARKED GLASSS SOLD AS SAFETY GLASS

The Window & Glass Association of New Zealand undertakes random testing of unmarked glass sold as safety glass. Even the experts cannot be sure what the result will be before the test is carried out.
The testing includes ensuring that the glass has broken correctly in accordance with AS/NZS 2208.
Ordinary glass breaks into dangerous shards. There are deaths from injuries with this type of glass, which is why the New Zealand Building Code has strict rules for using safety glazing materials in bathrooms and all other areas where human impact is likely.

DON’T TAKE THE RISK WITH YOUR FAMILY OF USING ORDINARY WINDOW GLASS IN HIGH RISK AREAS.

More information about The Window & Glass Association of New Zealand - Click Here.