Why is OC spray considered oil-based and how does this influence decontamination?

• A. It dissolves in water quickly, so rinsing alone is sufficient.
• B. It adheres to skin and surfaces; soap and water emulsifies and removes residue.
• C. It evaporates quickly and leaves no residue.
• D. It can only be removed with organic solvents.

Answer: (B)

OC spray is oil-based because its active capsaicinoids are lipophilic and cling to skin, hair, and surfaces as an oily residue. Water alone won’t wash this off effectively, since oil and water don’t mix. That’s why decontamination relies on soap and water: soap contains surfactants that emulsify the oil, breaking the residue into tiny droplets that a rinse can carry away. Thorough washing with soap and water, with repeated rinsing and some mechanical action, removes the oily residue more reliably than rinsing with water alone. It isn’t about evaporation or true water solubility, and while organic solvents could remove OC, they’re not appropriate for routine decontamination due to safety and irritation concerns. For eyes, flush with copious water or saline as a first step, then wash exposed areas with soap and water.