For maximum peace of mind we offer a service to heat soak glass pieces that we produce. Heat soaking is a test for very rare impurities in toughened glass that may cause it to break from structural stress.
As the name implies the glass is heated to 290°C for two hours. If Nickel Sulphide impurities exist in the glass, the piece will break.
Successfully completing the heat soak test indicates that the glass is very unlikely to have significant levels of damaging impurities, making it significantly less likely to break.
For more details on Nickel Sulphide please have a look at the side bar.