“Waterproof” on a box is marketing. The useful information is the IP rating printed in the specifications, and it describes exactly one laboratory test rather than a general promise about water.
- Device
- Any wet-use beauty device
- Time
- 10 minutes
- Tools
- Your specification sheet
- Difficulty
- No disassembly
Reading the rating
An IP code has two digits. The first covers solid objects and dust; where you see an X, as in IPX7, it simply means that aspect was not rated. The second digit is the one that matters for a bathroom, and it runs from splashes up to sustained immersion.
The important point is that the digits are not cumulative in the way people assume. A device rated for immersion has been tested for immersion; a device rated for jets has been tested for jets. Neither test necessarily covers the other, which is why some manufacturers publish two ratings.
- Splash-resistant Water landing on the device from above or at an angle. Enough for use at a basin, wiped afterwards. Not enough for the shower.
- Spray and jets Water directed at the device with force. This is the level that corresponds to shower use, because a shower head is a jet rather than a splash.
- Temporary immersion Submersion to a stated depth for a stated time — typically shallow and brief. This covers dropping the device in a full basin and retrieving it, not leaving it there.
- Continuous immersion Rare on beauty devices and always accompanied by conditions.
What the test does not include
Ratings are established with cold or ambient water on a new device. Three things in real bathrooms fall outside that.
Hot water and steam. Warm air inside a sealed device contracts as it cools, and a slight negative pressure draws moisture past seals that would hold against a static test. This is why some manufacturers specifically exclude hot showers and saunas.
Soap and surfactants. Cleansers lower the surface tension of water, which lets it enter gaps that plain water would bridge. A cleansing device is used with exactly these products by design, which is why seals matter more here than on a device used dry.
Age. Seals are usually rubber or silicone, and they harden, compress and lose elasticity over years. A rating describes a new device, and nothing about it is a warranty for year four.
Practical habits that outlast the rating
Rinse and shake out the device after use, then store it upright and open to air rather than face-down in a wet cradle. Dry the base and any charging contacts. Do not leave it sealed in a travel case while damp, which turns a bathroom problem into a mould problem.
If your device has a removable head, take it off periodically and let both parts dry. The junction between head and body is where water is most likely to sit unnoticed.
When water has already got in
Signs are a rattle that was not there, condensation visible under a window or indicator, erratic behaviour, or a device that runs only intermittently. Stop using it, do not charge it, and let it dry thoroughly in open air.
Do not attempt to open it to dry the inside. Opening a sealed device destroys the seal permanently, and on a device with a lithium cell it introduces a hazard that was not there before.
Sources
- Face washing 101 — American Academy of Dermatology