Tempered glass is glass that has been heated and then cooled in such a way as to increase the strength of the glass as well as to cause the glass to break in round pieces rather than sharp shards. Tempered glass is easily scratched and should never be cleaned with abrasive cleansers. Look in the corners of your glass for an etched emblem stating that the glass is "safety glass" or that it has been tempered. The least expensive cleaning agent—dish soap and water—works the best for tempered glass.
Things You'll Need
Soft dry cloth
Mix a 50/50 solution of simple dish soap and water in a spray bottle.
Spray the tempered glass with the water and dish soap mixture. Allow the mixture to soak into the dirt on the glass for 10 seconds before wiping off with a soft sponge (do not use a Teflon scouring pad). Stubborn areas may need a second spray and a second wiping with a soft sponge.
Buff the glass with a soft cloth.
A squeegee can be used on large areas of tempered glass, but be sure to allow the water and dish soap mixture to soak into the grime on the glass for 10 to 20 seconds before using a squeegee. Start by scraping the squeegee over only a small area of the edge of a window first to see if the squeegee is scratching the glass. Some (not all) tempered glass has tiny particles in the surface which can scratch the glass when a squeegee is used for cleaning.
Test any harsh cleaning products on a small area first. Many tempered glass shower doors, for example, are coated so you can use chemicals designed to cut hard water deposits without harming the surface of the glass.
Do not use steel wool or Teflon scouring pads. Do not use vinegar on tempered glass. Do not use abrasive powders on tempered glass