How to Dispose of Phosphoric Acid

In the classroom, phosphoric acid may be used to demonstrate the corrosive properties of acidic chemicals. Phosphoric acid is colorless and odorless, and is generally found as a solid or a thick, viscous liquid. It has a range of industrial and commercial applications, including metal rustproofing and fertilizer enrichment. Direct contact with the acid is dangerous, and can cause severe irritation of the skin and eyes. Though hazardous to the touch, phosphoric acid can be safely disposed of by dilution in water or natural absorption.

Things You'll Need

• Rubber gloves
• Safety goggles
• Sealable plastic container
• Dry sand or soil

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Instructions

• 1

  Don your rubber gloves and safety goggles prior to handling the phosphoric acid.

• 2

  Turn on your sink's faucet and allow the stream the run. Dispose of diluted phosphoric acid by pouring it slowly into the stream. Allow the water to run for several minutes afterward to weaken and fully flush the acid.

• 3

  Pour undiluted phosphoric acid into a large pitcher. Dilute the solution by filling the pitcher to the brim.

• 4

  Empty the pitcher near the base of a citrus tree or around the perimeter of your garden. The diluted acid serves to enrich the soil and provide healthful phosphates to growing plants.

• 5

  Fill a sealable plastic container halfway with dry sand or soil. Break up phosphoric acid solids and add them to the container.

• 6

  Add water to the container and mix the sand with the solids until moist. Seal the container and dispose of it at your nearest sanitary landfill. Alternatively, the sand or soil may be spread near the base of a citrus tree or over your garden.