They are safe, as long as they are handled properly. ShowerTan's tanning cartridges come in high-pressure CO2 cartridges like those used in seltzer bottles and airguns. Tanning cartridges must be kept at room temperature, must not be punctured or heated, and must be kept out of children's reach.
The ShowerTan home tanning system works with all skin tones and types. However, just like any other tanning method, results vary according to skin type. ShowerTan's STC Solution is formulated with 8.75% DHA, which generally provides a medium tan with one application on light or medium skin tones. People with very light skin might achieve better results by using water to dilute the solution to a ratio of between 4 parts to 1 and 2 parts to 1. Those with darker skin tones may need DHA booster drops that strengthen the solution, or use ShowerTan a bit more frequently in order to achieve the desired results.
After every use, you should clean the ShowerTan unit internally and externally. External cleaning is simply done by rinsing the unit with water. Internal cleaning is done by spraying through with water instead of solution. The starter and refill kits come with extra cartridges for cleaning after each use.
Though the misting nozzles could be directed away from your face, ShowerTan was meant to tan your whole body, including your face. The FDA has so far approved DHA only for external use. That means you should not expose mucous membranes like eyes, nasal passages, or lips, and you should not inhale or ingest. At this time, there's no scientific data which suggests any harm caused by exposure to mucous membranes, inhalation or ingestion. Still, we recommended that you close your eyes and mouth, and hold your breath during the 20 second mist spray process. It's up to you if you want to take any additional protective measures such as nose filters (offered in the Related Gadgets section below), lip balm, or eye goggles.