How mouthwash is made

A mouthwash batch can run 3,000 gallons, and a high-speed line then bottles over 20,000 an hour.

stations: 8
things upstream: 60
raw sources: 17
steps from the ground: 10

The short version

Compounders mix mouthwash in stainless steel tanks holding thousands of gallons. Deionized water and alcohol arrive by pipe, while flavors, antibacterial agents and dye are added by the operators, sometimes with a heating and cooling cycle. Once the lab approves a sample, the batch moves to a holding tank, and piston fillers load bottles at high speed.

Deionize the water

Water makes up over half of most formulas. It is treated first to strip the particles and ions that could change the flavor.

Goes in
Water
Charge the main tank

Forklifts bring raw materials to the compounding area, where operators add them to a stainless tank holding 2,000 to 3,000 gallons. Alcohol and water, used in bulk, are pumped in at the push of a button.

2,000 to 3,000 gallon batch

Goes in
Ethanol
Carry in the flavor

Flavor oils resist water. One patent mixes citrus flavor with ethanol first, then adds that blend to water already holding an emulsifier, along with a humectant and dyes. Agents such as thymol kill bacteria.
Heat, cool and stir

Some formulas are heated and cooled so the materials combine quickly. Computers hold mixing speed and temperature, and a batch takes one to three hours.
Send a sample to QC

Lab staff examine appearance and flavor, and may run pH and viscosity. A batch out of range can be corrected, for example with more dye.
Fill on the carousel

Approved liquid is pumped to a holding tank connected to the line. A hopper stands empty bottles upright on a conveyor, and piston heads on a carousel dose each one as it travels around.

Goes in
Plastic bottle
Cap and label

A second hopper lines up caps, which are twisted or pushed on. Labels feed from spools and are stuck on with adhesive or heat pressed.
Box and palletize

Bottles are gathered in groups of 12 or 24, dropped into boxes and stacked on pallets. Fast lines top 20,000 bottles an hour.

Goes in
Cardboard box

End of the lineMouthwash

Worth repeating

In the late 1960s, Harald Loe of the Royal Dental College in Aarhus showed that chlorhexidine can stop dental plaque from forming.
Some mouthwashes contain up to 27 percent alcohol by volume as a carrier for flavor.