Mouthwash is a liquid oral hygiene product intended to supplement brushing and flossing by rinsing away debris and freshening breath. Many formulations contain active chemical ingredients designed to fight bacteria and strengthen teeth. After vigorously swishing and spitting, a small amount of the liquid inevitably mixes with saliva, making people wonder if this remaining mixture is safe to ingest. This raises questions about the safety of any trace amounts left behind.
Safety of Residual Swallowing
The small, residual amount of mouthwash left in your mouth is generally considered safe for healthy adults to swallow. This tiny quantity is highly diluted by your saliva and any water you may have used for a final rinse. Toxicity is directly related to the volume ingested, and the trace amounts remaining after a proper spit are far below any level that would cause systemic harm. The body can easily process the minor chemical load without ill effect. The American Dental Association advises that accidental swallowing of minor amounts usually results in only mild, temporary symptoms, if any. The momentary contact with the digestive tract from this small residual volume does not pose a significant health risk to an otherwise healthy person.
Common Ingredients Causing Concern
Mouthwash formulas contain specific compounds that provide their therapeutic benefits but can be toxic in large quantities, which is the source of the public’s concern. Ethanol, or ethyl alcohol, is a common ingredient in many antiseptic rinses, sometimes making up between 5% and 27% of the total volume. This high alcohol content provides an antibacterial effect but can lead to alcohol intoxication if a person drinks a substantial amount, especially in children.
Fluoride is included in many mouthwashes to help strengthen tooth enamel and prevent decay. While beneficial on the tooth surface, ingesting excessive fluoride can cause gastric distress because it can irritate the stomach lining. Other active ingredients include chlorhexidine gluconate and cetylpyridinium chloride (CPC), which function as antimicrobial agents. These chemicals are highly effective against oral bacteria but are not formulated for consumption and can cause stomach upset if swallowed in larger volumes.
Recognizing Symptoms of Accidental Ingestion
While swallowing residual mouthwash is generally harmless, ingesting volumes larger than a trace amount can lead to noticeable symptoms. Mild adverse effects from an accidental gulp often include temporary stomach upset, nausea, or a brief burning sensation in the mouth or throat. These minor irritations typically resolve quickly without intervention.
More concerning symptoms arise when a large volume is consumed, particularly if the mouthwash contains alcohol or high levels of fluoride. Ingesting significant amounts of an alcohol-based formula can lead to signs of intoxication, such as confusion, dizziness, or unusual drowsiness. Severe cases of ingestion, such as a child drinking from the bottle, may present with vomiting, abdominal pain, difficulty breathing, or even seizures due to toxicity from ingredients like fluoride or methyl salicylate. If a large amount of mouthwash has been swallowed, or if severe symptoms like difficulty breathing or loss of consciousness occur, immediately contact Poison Control for guidance on the proper course of action.
Minimizing Ingestion Through Proper Use
Users who are still anxious about swallowing any amount of mouthwash can take steps to minimize residual ingestion. Ensuring a vigorous and complete spit after swishing for the recommended 30 to 60 seconds removes the majority of the solution from the oral cavity.
A final, quick rinse with plain water immediately after spitting out the mouthwash will significantly dilute and wash away any remaining surface residue. Although some dental professionals advise against rinsing with water after a fluoride rinse to allow the active ingredient to remain on the teeth, a water rinse is an effective way to minimize the amount of chemical-laden liquid available to be swallowed. Keeping mouthwash bottles stored securely out of reach of small children is a critical safety measure, as they are most vulnerable to the toxic effects of ingesting a large volume.