Can I use relays with 10A125V~ for my 220V~ applications, safely?

I am using the TinkerKit Relay Module and recently they changed the relay mounted on the board from a white one with 10A250V~ to a black one with 10A125V~.

In my country the voltage is 220V~. Can I use the black relay in my application, safely? May be there problems that I have to be careful?

Well now, here's the point.

The relay has a rating marked on it. What is the point of putting a rating on it?

Definitely not - otherwise the manufacturer would have marked it with 240V.

You should complain to the supplier that the module doesn't meet its specification, they should't be doing this, its a fire risk above anything.

What can it happen?

The contacts would weld closed, most likely. There is a fire risk as well. I would not use those relays for 220V.

What can it happen?

Your house could burn down. Is that a problem ?

From the image at the link provided, it looks like "JS1-5V-F". If so, this would be the datasheet: JS Relays You'll need to identify the complete part number for the relay, then identify what the AC ratings are for your specific relay. Also, verify that you have the appropriate datasheet.

Newer ever use underrated parts when dealing with line voltages.. least of your problem is relay contacts to weld stuck... on more serious end is fire, burning down a house, being denied insurance claim because not used proper parts, etc...