What is used to neutralize spilled electrolyte from a nickel-cadmium battery?

• A. Solution of boric acid and water.
• B. Sodium bicarbonate and water.
• C. Vinegar and water.
• D. Calcium hydroxide and water.

Answer: (A)

Spilled nickel-cadmium battery electrolyte is potassium hydroxide, a strong alkali. The cleanup goal is to reduce the caustic hazard by neutralizing the base with an acid, then flushing with water. Boric acid in water is a mild acid that reacts with the base to form potassium borate and water, which lowers the hazard without generating significant heat or fumes. This gentle, controlled neutralization makes it a safer, practical choice for NiCd spill cleanup and is commonly recommended in maintenance safety guidance.

Sodium bicarbonate or calcium hydroxide are bases themselves, so they won’t neutralize the spill and can leave alkaline residue. Vinegar would neutralize the base, but it’s a stronger acid option and less ideal in a controlled maintenance cleanup compared with the milder boric acid.