In article ,
Stu wrote:

I plan on replacing my counter tops. I will be using plywood for the
laminate on the horizontal surfaces but am wondering if MDF can be
used for the back splash. Any comments or suggestions?

MDF is just fine for a countertop. Better in my opinion than plywood,
because plywood can delaminate.
Use an ample amount of contact cement on the edges starting by one coat
thinned then, when it has dried overnight, another two coats of regular
consistency contact cement.

In most cases, regular particle board is a good way to go.