What is used to neutralize the electrolyte from nickel-cadmium battery that has been spilled on an aircraft structure?

• A. A solution of boric acid and water, or vinegar.
• B. Bicarbonate of soda and water.
• C. Sodium hydroxide and water.
• D. Hydrochloric acid and water.

Answer: (A)

The electrolyte in nickel-cadmium cells is potassium hydroxide, a strong base. When it spills on aircraft structure, neutralizing the base with a mild acid is the right approach to stop its caustic action and reduce corrosion. Vinegar (acetic acid) or boric acid solutions provide a gentle neutralization: potassium hydroxide reacts with acetic acid to form potassium acetate and water, lowering the pH and rendering the spill less harmful to surfaces. A simple reaction you can think of is KOH reacting with acetic acid to produce a salt and water.

Baking soda is basic, so it wouldn’t effectively neutralize the spill and could leave alkaline residues. Sodium hydroxide would worsen the spill by increasing alkalinity. Hydrochloric acid, while an acid, is more aggressive and can be harsher on surfaces and create additional handling hazards in an aircraft environment. That’s why a mild acid like boric acid or vinegar is the recommended neutralizer.