You can use on -
Tile, Stone, Grout, Concrete and Glass. 

You can Not use on -
Painted Surfaces(this cleaner is a mild striper and will remove water based paints or coatings),
Metal(if allowed to sit to long,(days, not minutes) it will corrode the metal)

PPE -
Goggles or face mask, respirator in ventilated area, gloves and arm protection.  

Precautions -
Keep out of reach of children and animals. 
If Inhaled -
Mild irritation. 
(Move to fresh air, if experiencing trouble breathing call 911, otherwise call poison control center). 
If in Eyes -
Avoid contact with eyes, clothing and skin, may cause inching burning.
(Immediately flush skin and eyes with water for at least 15 minutes.)
If Swallowed -
Do not drop or strike containers.
(Call a poison control center immediately, sip a glass of water if able to swallow and do not induce vomiting unless told to do so by poison control center).  

Instructions -
Mix half bottle or 8oz per gallon of hot water. First remove any damaged grout or caulk and vacuum areas. Spray or apply to surfaces as needed and let dwell for 5 minutes, you may reapply as needed. Scrub all grout using our grout scrub brush, reapply cleaner and scrub all tile surfaces using a green scrub pad or floor scrubber(For glass and polished stone, use a non scratching white scrub pad or proper floor scrubbing pad). Rinse well with water and vacuum(For shower floors, lightly rinse again and vacuum dry.

For showers, vacuum perimeter and cracked grout within floor as the pan may be collecting or holding excess water.