How much safer are you when using Personal Protective Equipment?
Work should be engineered so that PPE is not necessary.
If that cannot be done, as much as can be engineered should be,
and then a variety of administrative controls may be useful in
further improving safety.
Only after engineering and administrative controls have failed
to get you to the level of safety you need, or while they are being
designed and implemented, should PPE be needed
At that point you are safer using PPE than not, but it is not
possible to put a number on that in a general discussion like this
one. Always ask for PPE if you think it is needed and use it when
provided. The specific kind of PPE needed depends on your job, the
work you preform, and the materials you use or that are used near
you..