What Are Smelling Salts Made Out Of? Key Ingredients Explained
Smelling salts are made out of ammonium carbonate or ammonium bicarbonate mixed with water and alcohol, along with a scent like lavender or eucalyptus. The active ingredient is ammonia gas, which is released when the salts are crushed or the container is opened. This gas irritates the membranes in the nose and triggers an involuntary inhalation reflex that can briefly increase alertness.
How Ammonium Carbonate Works
The core chemistry is straightforward. Ammonium carbonate is a salt that decomposes into ammonia gas and carbon dioxide when exposed to air. The ammonia gas creates the sharp, pungent smell. When you inhale it, the gas irritates the trigeminal nerve in your nasal passages. That nerve sends a signal to your brain that forces you to take a deep breath and increases your heart rate and blood pressure.
This reaction is why smelling salts have been used for centuries to revive people who have fainted. The sudden inhalation reflex pulls in more oxygen, and the increased circulation helps bring someone back to consciousness. Modern sports medicine uses the same principle. Athletes in contact sports sometimes use smelling salts before a play to boost their alertness and reaction time, though the effect is very short-lived.
The Difference Between Ammonium Carbonate and Ammonium Bicarbonate
Not all smelling salts use the same chemical. Some products use ammonium carbonate, while others use ammonium bicarbonate. Both release ammonia gas, but ammonium carbonate tends to be more stable and has a longer shelf life. Ammonium bicarbonate decomposes more quickly and can produce a stronger initial burst of ammonia. The choice between the two comes down to the manufacturer’s formula and how fast they want the effect to hit.
The Role of Alcohol and Water
The solid ammonium compound is dissolved in a mixture of water and alcohol, usually ethanol or isopropyl alcohol. The water helps dissolve the ammonium compound so it can be stored in a liquid form. The alcohol serves two purposes. It helps the solution evaporate quickly once exposed to air, which speeds up the release of ammonia gas. It also acts as a preservative, preventing bacterial growth in the bottle.
The ratio of alcohol to water affects how strong the salts smell when you open the container. A higher alcohol content means faster evaporation and a more immediate ammonia burst. A lower alcohol content produces a slower, more gradual release. Most commercial smelling salts use a roughly equal mix of water and alcohol, but this varies by brand.
Fragrance Oils and Why They Are Added
Pure ammonia smells like cleaning solution and can be unpleasant or even nauseating. To mask that harsh odor, manufacturers add fragrance oils. Common scents include lavender, eucalyptus, peppermint, and rosemary. These oils do not change the chemical reaction. They simply add a layer of smell on top of the ammonia.
The fragrance also serves a practical safety purpose. Without it, a person might accidentally inhale too deeply and get a dangerously strong dose of ammonia. The added scent gives the user a moment to register the smell before the ammonia hits, so they can control their breathing. It also makes the product less likely to cause a gag reflex. The National Capital Poison Center notes that concentrated ammonia solutions can cause burns and respiratory damage if used improperly National Capital Poison Center. The fragrance helps reduce the risk of overexposure by making the experience less jarring.
How the Ingredients Are Combined
The manufacturing process is simple. The ammonium compound is mixed with water and alcohol in a sealed container. The mixture is heated gently until the solid dissolves completely. Once the solution cools, the fragrance oil is added. The final product is a clear or slightly cloudy liquid poured into small glass ampules or plastic tubes.
When you break the ampule or open the tube, the solution is exposed to air. The alcohol evaporates quickly, carrying the ammonia gas with it. The remaining liquid is mostly water and fragrance oil, which dries quickly. The entire reaction lasts only a few seconds, which is why smelling salts are meant for immediate, single-use applications.
Safety Considerations and Proper Use
Smelling salts are generally safe when used as directed, but they are not harmless. The National Center for Biotechnology Information describes ammonia as a potent respiratory irritant National Center for Biotechnology Information. People with asthma, chronic lung conditions, or heart problems should avoid them. The sudden spike in heart rate and blood pressure can be dangerous for someone with an underlying condition.
Smelling salts should never be used on an unconscious person who might have a spinal injury or head trauma. The reflex jerk of the head and neck can cause additional injury. They are also not a treatment for serious medical emergencies like a stroke or cardiac event. If someone collapses and does not wake up within a few seconds, call emergency services immediately.
Some people try to make their own smelling salts using household ammonia. This is not safe. Household ammonia is much more concentrated than the ammonium carbonate used in commercial products, and it often contains additives like bleach or detergents. Inhaling those fumes can cause chemical burns in the lungs. The National Capital Poison Center warns that mixing ammonia with bleach creates toxic chloramine gas National Capital Poison Center. Stick with commercial products designed for inhalation.
Key Takeaways
- Smelling salts are made from ammonium carbonate or ammonium bicarbonate dissolved in water and alcohol, with added fragrance oils.
- The active ingredient is ammonia gas, which irritates the nasal membranes and triggers a reflex inhalation that increases alertness.
- Alcohol helps the solution evaporate quickly and preserves the product, while fragrance oils mask the harsh ammonia smell and improve safety.
- Smelling salts are safe for short-term use in healthy individuals but can be dangerous for people with respiratory or heart conditions.
- Do not use homemade smelling salts or household ammonia products, as they can cause serious injury.
