Phosphoric acid is used as a cleaner by construction trades to remove mineral deposits, cementitious smears, and hard water stains. It is also used as a chelant in some household cleaners aimed at similar cleaning tasks.

Rust removal Phosphoric acid may be used as a "rust converter", by direct application to rusted iron, steel tools, or surfaces. The phosphoric acid converts reddish-brown iron(III) oxide (rust) to black ferric phosphate, FePO4.

After treatment, the black ferric-phosphate coating can be scrubbed off, leaving a fresh metal surface.b Multiple applications of phosphoric acid may be required to remove all rust. The black phosphate coating can also be left in place, where it will provide moderate further corrosion resistance.

Phosphoric acid is registered as a bactericide and disinfectant. It is used to disinfect dairy farm milk handling facilities, equipment and dairy animals, and food processing water systems. It is also used to disinfect food processing/handling areas, kitchens, and bathrooms. It may also be used in eating establishments for sterilizing equipment and utensils.

2 liters is $65 including delivery $70 for rural delivery.