You won't break anything if you put it into your Materials folder and try it in the material room. I know Poser 5 material files work in Poser 6, but I'm not sure if the files work in older versions. I don't see why they shouldn't.

If it doesn't work, just delete the file from the Materials folder :)

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi