Related Clues:

• __ test
• Sulfuric ___
• Nitric ___
• Soap ingredient, once
• More common name for caustic soda
• Strong drain cleaner
• Etching stuff
• It's not basic
• Need for 41-Across
• Biological food processor
• Liquid that can eat through metal
• ___ rock
• Alkaline solution
• Some take it for trips
• Caustic drain-opener