I have questions about the razor blades
Our safety razor blades are universal. :)
Razor blades are considered medical waste, so they're incinerated. However, you could ask your local pharmacies if they have a box to collect them (some barbers also have these).
In France, these boxes are yellow, and will be burned once they're filled. You can throw your razor blades in the bin, but make sure they're wrapped in something so they can't pierce your bin bag or injure anyone. At present, TerraCycle doesn't have a solution for recycling razor blades in Europe, but they are testing this in the USA. :)