Annealed Glass
Standard float glass that has been slowly cooled during manufacturing without additional heat treatment, making it the base product from which tempered and heat-strengthened glass are made.
Annealed glass is the most common and least expensive glass type. It breaks into large, sharp shards and does not qualify as safety glass. It is used in standard window applications where safety glass is not required by code.
When annealed glass breaks, the sharp fragments can cause serious injury, which is why building codes restrict its use in hazardous locations. Most residential window IGUs use annealed glass unless safety glass is specifically required for the installation location.