Tempered glass is not shatterproof nor unbreakable.

It is heat treated in ovens to create a much stronger glass than annealed

or non-tempered glass.

The Safety Factor is when tempered glass breaks,

it falls in thousands of little 1/4" pieces,

instead of coming down in big pieces much like a guillotine

and could cause severe lacerations.

Used in automobile side and rear windows

and by Federal Law it is installed in and within 48" of any entrance door.