Pepper spray (OC spray, or Oleoresin Capsicum) is a widely used self-defense and law enforcement tool designed for temporary incapacitation. Its primary function is to immediately produce intense irritation and pain upon contact with the eyes, respiratory system, and skin. This effect is achieved through a powerful inflammatory reaction that disorients and subdues an individual without causing permanent injury. Understanding the spray’s chemical nature differentiates its intense sensory effects from true tissue damage.
The Chemical Cause of Pain
The intense sensory experience of pepper spray stems from its active ingredient, Oleoresin Capsicum (OC), a natural extract derived from chili peppers. This extract contains chemical compounds called capsaicinoids, with capsaicin being the most potent. The concentration of capsaicinoids determines the spray’s strength, measured in percentages of Capsaicin and Related Capsaicinoids (CRC).
When these oily capsaicinoids contact the skin, they bind directly to specific sensory nerve endings—the body’s natural pain receptors. These receptors are normally activated by physical heat or abrasion, signaling the brain to perceive a burning sensation. The chemical interaction creates immediate, searing pain, making the body believe it is being burned. This neurogenic inflammation is the core mechanism of the spray’s incapacitating effect, causing involuntary reactions like eye closure and difficulty breathing.
Skin Reaction Versus Chemical Burn
The burning sensation from pepper spray is a powerful neurological signal, but it is not the same as a chemical burn that destroys tissue. The substance is primarily an irritant and inflammatory agent, causing intense discomfort, redness (erythema), and swelling (oedema). The physical effects generally resolve without lasting harm, though they can persist for 30 minutes to two hours depending on the concentration and decontamination level.
While the spray is not corrosive, prolonged contact or ineffective removal can result in more than just irritation. Individuals may experience persistent dermatitis, severe redness, or temporary blistering and rash. Reports of second-degree burns are rare and associated with severe, high-concentration exposure or improper decontamination that traps the oil-based capsaicinoids against the skin. The effect is an acute inflammatory response that mimics a thermal burn rather than a true corrosive injury.
Immediate Steps for Relief
Immediate action is necessary to minimize the duration and severity of effects if the skin is exposed to pepper spray. First, remove any contaminated clothing and move to an area with fresh air to prevent further inhalation. Avoid rubbing the affected area, as this spreads the oil-based capsaicinoids and forces them deeper into the pores.
Since the spray is oil-based, water alone is ineffective for complete removal. The affected skin must be flushed with large quantities of cool water for at least 15 to 20 minutes. Follow this with gentle washing using a mild, oil-neutralizing soap, such as baby shampoo or dish soap. Cool water is necessary because hot water opens the pores, allowing capsaicin to penetrate more deeply and intensifying the burning sensation. Avoid applying ointments, creams, or lotions, as these trap the irritant against the skin and prolong discomfort.