I used hydrochloric acid and water to remove concrete from my tools (in a plastic bucket) but did not know how dangerous it was and how complicated the disposal process can be--first time using it obviously. It is pretty late at night and there's not much I can do but I am scared to leave it outside overnight uncovered and I don't have a lid for it

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    You can neutralize it with baking soda. Add very slowly it will foam up. Stop slowing adding when it quits reacting (foaming). Then I mix in more water and eventually put it down a floor drain with more water.
    – Tyson
    Oct 3, 2017 at 9:25
  • ashes are a cheap base that often go to waste...
    – dandavis
    Oct 4, 2017 at 7:33

1 Answer 1


You can neutralise the acid by mixing with alkali. However, be careful.

You will need quite a lot of something like baking powder. Or if you have any left over - cement powder.

Add a small amount to the acid - it will foam and release gas (Carbon Dioxide). Don't add too much at once or the bucket will overflow and you will get acid everywhere.

Keep going, small amount at a time until it no longer foams when you add more. You now have salty water that can be poured down the drain.

I repeat, be careful because of the foaming and you will need a lot of powder.

  • Sodium hydroxide combined with hydrochloric acid will produce precisely table salt and water. However you want to finish with ordinary household products you have practical uses for. It defeats the purpose to neutralise the acid only to have a half bag of caustic lye to dispose of! Now you need more acid! (Good household-friendly acid: vinegar.) Oct 3, 2017 at 15:22

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