Exposure to mace or pepper spray causes an intense, immediate burning sensation on the skin, eyes, and respiratory system. This powerful reaction is the body’s response to a chemical irritant designed for temporary incapacitation. Dealing with this discomfort requires swift action to neutralize the chemical and obtain relief. Understanding the science behind this burning is the first step toward effective decontamination.
Understanding the Chemical Irritation
The intense burning sensation is caused by the active ingredient in pepper spray, a resin known as Oleoresin Capsicum (OC). This oil-based substance contains capsaicinoids, the compounds that give chili peppers their heat. When OC contacts the skin, these capsaicinoids bind to sensory nerve receptors called Transient Receptor Potential Vanilloid 1 (TRPV1).
The TRPV1 receptor is typically activated by high temperatures, specifically anything above 109°F (43°C), or by acidic conditions. Capsaicin tricks the nerve cell by binding to and “unlocking” this receptor, allowing calcium ions to flow into the cell. This influx generates an electrical signal that the brain interprets as intense heat and burning pain, even though no actual thermal burn has occurred. The painful sensation is a form of neurogenic inflammation.
Immediate Steps for Skin Decontamination
The first step is to move away from the contaminated area into fresh air immediately. Pepper spray particles can linger, and staying in the same space will prolong respiratory and skin irritation. Next, remove any contaminated clothing, ideally by cutting it off rather than pulling it over the head, to prevent spreading the irritant. Contaminated items should be placed in a sealed bag to avoid cross-contamination.
The active ingredient, capsaicin, is oil-based, meaning rinsing with water alone will not fully dissolve or remove it. A detergent is necessary for effective decontamination because water cannot break down the oil. Flush the affected skin with copious amounts of cool water for at least 15 to 20 minutes. Using hot water is counterproductive because heat can open the skin’s pores, potentially increasing capsaicin absorption and worsening the burning sensation.
After the initial rinse, gently wash the skin using a mild, oil-free detergent, such as dish soap, to help break down the oily OC. Avoid using soaps with heavy fragrances, as these can contain alcohol or other ingredients that may increase skin irritation. Specialized decontamination wipes are also available and can be effective in neutralizing the chemical agent. Avoid rubbing the skin, as this action can push the chemical deeper into the pores or spread it to a wider area.
After washing, gently pat the skin dry with a clean towel instead of rubbing it. Avoid applying any oil-based products, such as lotions, creams, or petroleum jelly, because these substances will trap the capsaicinoids against the skin. Trapping the chemical prevents its evaporation and prolongs the burning sensation. Some people find temporary relief by applying a cool compress soaked in milk or a solution of antacids and water.
Recognizing and Treating Lingering Symptoms
Even after thorough decontamination, some residual discomfort is common, with symptoms typically lasting anywhere from 30 minutes to a few hours. The lingering pain is managed with a cool compress, which can reduce irritation and swelling. Over-the-counter pain relievers may also be used to manage the remaining discomfort.
Special attention must be paid to the eyes, which are highly sensitive to the chemical. They should be flushed with cool water for 15 minutes, allowing the water to run from the inner corner outward. If contact lenses were worn, they should be removed and discarded immediately. Airway irritation, characterized by coughing or difficulty breathing, is common, and a person with pre-existing respiratory conditions like asthma must be monitored closely.
Seek immediate medical attention if you experience severe or worsening breathing difficulties that do not subside in fresh air. Other indicators for professional care include persistent, intense eye pain, blurred vision, or an inability to open the eyes. A doctor should also evaluate any signs of a chemical burn on the skin, such as blistering, or if intense symptoms last for longer than 24 hours.