Not sure if there is a such thing. Only reason I'm asking is because a lot of coworkers & myself have been asked to do job that are way over our payrate with no recognation... I didn't know if we could deny the work other than what we get paid for in follows to our job title

There are fair labor laws but you have not given us much to work with, more details are needed. Where are you located. Compliance Assistance By Law - The Fair Labor Standards Act (FLSA)

Hourly, Salary, union??

Myself for example... I'm titled a packer, packing items into displays in assembly... however I do shipping & receiving, I run assembly lines, inventory,supervise a project that is year around, I help project management with special projects & designs... I enjoy doing all of this but when struggling living pay check to pay check I'm tired of giving my all with nothing in return nor nothing to show for it, not even a better job title to go look for a better job...

Some employers reward good work and extra areas of work, but many don't. YOU have to walk in to personnel and say that you deserve a raise and a promotion. Plan it. Don't be negative and demanding, but don't be meek. It's a thin line. Keep it short too. Describe all you have done outside your job description and for how long (positive), say that you value the experience (positive), and now you deserve that raise and promotion. Either walk in and remain standing and end with something about expecting an answer in 3 days, or make an appointment. Think carefully about every single moment of how you will do this. Don't waffle or say um. If the person needs more than 3 days, say you can go 5 days, but that there's a reason why you can't wait longer than that. (That implies a job offer, but don't lie and if asked, say you won't say.) It's always a risk, but if you do it right, it's worth it, and you should be respected for it.

Titles mean nothing if all the jobs pay the same. Management has a right to direct their resources as they are needed. If they pay you for the days/hours you work elsewhere you have no beef, so the question becomes is there a difference in pay that goes with those titles?

Whether your pay is adequate has no bearing on this matter since you agreed to the level of pay when you took the job. Refer to your company handbook.

Companies are trying to get by with less employees so they are adding more duties to employees work load. And they are not necessarily increasing pay.

There is nothing illegal about it. If you are union you talk to your shop steward. If not, you talk to your supervisor or HR about the fact that your duties and responsibilities have increased and that you feel you are entitled to an increase in pay.