We have a non-proift organization that has never 1099 any worker. These workers are considered volunteers because they don't get paid very much but over a course of a year some do make $600 or more. We want to 1099 all those that apply but volunteers are upset and feel that is wrong. Is there some kind of exemption for volunteers who get compensated for work done at a non-profit organization?

A volunteer does not get paid, they give their time.

Are they being paid merely expense ( lunch or gas money ?)
But if they are actually being paid, they will either be an employee or a 1099 worker. Now they will have to meet the requirements for a 1099 worker, if not then they have to be considered an employee.