Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Sodium hydroxide for etching |lifetime |disposal |

  1. Jan 1, 2013 #1
    Hi there :)
    I have 10g of NaOH whit 1 liter of water for photo etching
    Solution is one year old, and do i need to make new one (is there a lifespan of solution) ?
    If yes how to dispose it safely ? (can it be disposed in regular drain ?)

    thanks for your time :)
  2. jcsd
  3. Jan 1, 2013 #2


    User Avatar

    Staff: Mentor

    Quite likely it absorbed enough atmospheric CO2 it doesn't qualify as "NaOH" solution, but NaOH/Na2CO3 solution.

    At this concentration you can safely pour it down the drain.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook