For chemical spills involving metals such as sodium, lithium, calcium, or magnesium, what irrigation fluid is preferred?

• A. Water
• B. Mineral oil
• C. Normal saline
• D. Sterile water only

Answer: (B)

When metals such as sodium, lithium, calcium, or magnesium are involved, the danger comes from their vigorous reaction with water, which releases heat and hydrogen gas and can worsen tissue injury. Using a plain aqueous irrigation fluid would invite this reaction, spreading the metal and increasing harm. Mineral oil is preferred because it is inert and nonreactive with these metals; it can blanket and help remove metal residues without triggering a water-based reaction, effectively smothering further contact with moisture while still aiding decontamination. Water-based irrigants like water or normal saline would not be as safe in this setting, since they can react with the metal and worsen the injury.