An IP68 badge can tempt a buyer to dunk a used phone to “prove” it is safe. That test can damage a device and cannot certify future sealing. Apple and Samsung both warn that water resistance is not permanent and may decrease with normal wear. For a used unit, inspect its history, physical condition and purchase terms instead.
1. Read the IP68 label in context
An IP rating describes protection against dust and water under specified test conditions. Do not assume iPhone 15 Pro and Galaxy S23 were tested to identical depths and durations merely because both carry IP68; read each manufacturer’s details. Laboratory conditions also differ from seawater, pressure jets and accidental impacts.
The model name tells you its original design, not the present sealing of the unit in your hand. An intact label or absence of a past liquid warning is not a water-resistance guarantee.
2. Why is a used phone different?
Seals, adhesive and the chassis can be affected by age, heat, drops or repairs. Apple says resistance can decrease with wear; Samsung makes a similar warning for Galaxy devices. If a screen or back cover was replaced, ask what work was done instead of assuming factory-level resistance was restored.
A quick splash at a counter cannot prove that a future rain shower will be harmless. It can instead damage the phone while leaving you unsure where water entered.
3. What can you inspect without water?
Look for gaps, bends and signs of repair around seams; inspect the charging port, speakers and camera area. Ask about drops, liquid exposure and parts replacement, retaining any available repair documents. Record the condition described in your order. These steps do not certify a seal, but they reveal risks more honestly.
Test speakers, microphones, cameras, charging and touch while everything is dry. If you see moisture or marks behind a camera lens, pause the purchase and request a technical inspection rather than trying to heat-dry the phone yourself.
4. What if the phone later gets wet?
Stop charging and follow the manufacturer’s liquid-exposure instructions for the exact model if behaviour becomes abnormal. Apple warns against charging a wet iPhone; Samsung also provides guidance after water exposure. Avoid high heat or repeatedly turning the device on just to see whether it still starts.
Read the seller’s warranty and return policy before purchase, especially its liquid-damage terms. Used-unit coverage may differ from a new-phone warranty; an IP68 label does not automatically make water damage a covered claim.
5. Prefer an individual unit with clear information
Both the used iPhone 15 Pro and used Galaxy S23 belong to model lines with IP68 ratings in their manufacturers’ documentation. At TECHBUY, ask about the actual device’s condition and support terms rather than turning the new-model rating into a promise for a used phone.
If your work regularly takes you into damp environments, plan suitable protection and data backups. Water resistance reduces risk; it is not a reason to treat a phone as an underwater camera.
Conclusion
Do not test a used phone by dunking it. History, condition, function checks and purchase terms provide more useful evidence. Sources: Apple on iPhone water resistance and Samsung on Galaxy IP ratings.
