The store site informs that C Case has IP40 Water resistant. But I have read the definition of IP40 that it is not protected from liquids.
No, it's not water proof. It's fine if it get splashed with a bit of water
IP40 = water resistant. You should google this, there are many charts available on the internet.
First Digit (intrusion protection):
1. No special protection
2. Protection from a large part of the body such as a hand (but no protection from deliberate access); from solid objects greater than 50mm in diameter.
3. Protection against fingers or other object not greater than 80mm in length and 12mm in diameter.
4. Protection from entry by tools, wires etc, with a diameter of 2.5 mm or more.
5. Protection against solid bodies larger than 1mm (eg fine tools/small etc).
6. Protected against dust that may harm equipment.
7. Totally dust tight.
Second Digit (moisture protection):
1. No protection.
2. Protection against condensation
3. Protection against water droplets deflected up to 15° from vertical
4. Protected against spray up to 60° from vertical.
5. Protected against water spray from all directions.
6. Protection against low pressure water jets (all directions)
7. Protection against strong water jets and waves.
8. Protected against temporary immersion.
9. Protected against prolonged effects of immersion under pressure.