Smelling salts are a preparation designed to provide a rapid, stimulating effect when inhaled. Their primary purpose has historically been to revive individuals who have fainted or to enhance alertness. These compounds deliver a strong, pungent sensation that triggers a physiological response, restoring awareness. This immediate, intense reaction gives smelling salts their characteristic “strength.”
The Chemical Basis of Their Strength
The potent sensation from smelling salts originates from the chemical reaction of their main ingredient, ammonium carbonate. This colorless, crystalline solid, often found in traditional formulations, decomposes when exposed to air and moisture, releasing ammonia gas (NH₃), carbon dioxide, and water vapor.
Modern smelling salts may also consist of a dilute solution of ammonia in water and ethanol, sometimes with added scents. Regardless of the specific preparation, the rapid release of ammonia gas produces the distinctive, sharp odor and the powerful “strength” perceived when inhaled.
How Smelling Salts Affect the Body
When inhaled, ammonia gas strongly irritates the mucous membranes lining the nose and lungs. This irritation stimulates the trigeminal nerve, responsible for facial sensations. The body’s immediate, involuntary response is an inhalation reflex.
This reflex causes an abrupt increase in breathing rate and depth, helping to clear airways and send more oxygen to the brain. The stimulation also leads to a temporary rise in heart rate and blood pressure, activating the sympathetic nervous system, associated with the “fight or flight” response. These physiological changes contribute to heightened alertness and can help revive someone feeling faint or who has lost consciousness.
Common Uses and Misconceptions
Historically, smelling salts were widely used to revive individuals who had fainted, a common occurrence in Victorian times. Today, they are also used in sports, particularly by athletes in contact sports like powerlifting, hockey, and American football, for a temporary boost in alertness and focus before activity.
A common misconception is that smelling salts provide a sustained energy boost or enhance physical strength. While they can increase alertness and focus, limited scientific evidence supports claims of improved muscle strength or lasting performance. Their effect is primarily stimulatory, triggering an acute physiological response rather than a true performance-enhancing benefit. Using them to mask the effects of a head injury is a serious concern, as it can delay necessary medical assessment.
Safety Considerations and Proper Use
Smelling salts carry potential risks, especially with misuse or overuse. Ammonia gas can cause irritation and chemical burns to the nasal passages, eyes, and skin if held too close or used excessively. Inhalation of concentrated ammonia can also lead to respiratory problems and, in severe cases, permanent lung damage.
It is recommended to hold smelling salts approximately 4 to 6 inches (10-15 cm) away from the nose during inhalation to minimize irritation. Individuals with existing respiratory conditions, such as asthma or bronchitis, should avoid them as they can worsen symptoms. While generally considered safe when used occasionally and as directed, they should not substitute proper medical attention, particularly for head trauma or persistent dizziness.