Ammonia towelettes, commonly known as smelling salts, are specialized first-aid items used to stimulate a rapid physical response. They are typically found in first-aid kits and athletic training environments. The purpose of these inhalants is not medical treatment, but rather to quickly rouse a person experiencing lightheadedness or a loss of consciousness. Their action relies on a strong, pungent vapor that triggers an immediate, involuntary reaction.
Defining Ammonia Towelettes
Ammonia towelettes are single-use, pre-saturated wipes enclosed in a small, sealed foil packet. The packet must be crushed or torn open immediately before use to release the active components. The wipes are saturated with a liquid solution primarily containing ammonia, ethanol (alcohol), and purified water. Ammonia concentration often ranges from 15% to 30%, formulated as a fast-acting respiratory stimulant. Once the seal is broken, the ammonia gas rapidly volatilizes, creating the characteristic sharp, acrid odor.
Addressing Fainting and Syncope
The primary intended use for an ammonia towelette is to prevent or treat episodes of syncope, the medical term for fainting. Syncope is a temporary loss of consciousness caused by a sudden, brief reduction in blood flow to the brain. The towelette is administered when a person is feeling presyncopal—dizzy, lightheaded, or about to faint—or after a brief loss of consciousness has occurred.
The pungent vapors are quickly waved under the person’s nose to elicit a powerful and immediate reaction. This stimulation rapidly revives consciousness and helps prevent secondary injuries from a fall. Ammonia inhalants are also commonly seen in sports to quickly increase alertness in athletes who may be temporarily stunned or groggy. The goal is to provide a swift jolt of sensory input to counteract the temporary drop in brain function.
Scientific Mechanism of Action
The mechanism of action for ammonia towelettes centers on their nature as a chemical irritant that triggers a powerful reflex. When the ammonia gas is inhaled, it irritates the sensitive mucous membranes lining the nose and lungs. This intense irritation stimulates the trigeminal nerve, the fifth cranial nerve responsible for sensation in the face.
Stimulation of the trigeminal nerve causes an involuntary protective reflex known as the inhalation reflex. This reflex results in a sharp, sudden intake of breath, accompanied by an increase in heart rate and blood pressure. For a person experiencing syncope, which is often caused by excessive parasympathetic activity slowing the heart, this sympathetic irritant effect counteracts those vagal effects. The rapid increase in heart rate and blood pressure helps to restore oxygen flow to the brain.
Proper Usage and Safety Warnings
Ammonia towelettes must be used with caution to avoid chemical injury, as the ammonia solution is corrosive. Proper technique involves tearing open the packet and gently waving the towelette a safe distance from the person’s nose, typically four to six inches away. Do not hold the wipe directly against the nostrils, as this can cause painful chemical burns to the nasal passages, eyes, or skin.
Several important safety contraindications must be observed before using an ammonia inhalant. They should never be administered to someone known or suspected to have a head, neck, or spine injury, as the sudden, involuntary head movement could exacerbate the injury. People with pre-existing respiratory conditions, such as asthma or bronchitis, should not use them, as the irritant gas could worsen breathing difficulties. If a person does not quickly regain consciousness, or if there are concerns about breathing or circulation, immediate emergency medical services should be called instead of repeatedly administering the towelette.