When you're doing too many jobs that aren't part of your job description...

when you cannot do it anymore it's time to say "I think I am no longer efficient to that". Of course saying something like that to your manager will mark you as someone not willing to do other tasks beyond your responsibilities. But for me, as long as I can do the tasks and I am learning something new I consider it as my benefit and as a way to improve my skills and knowledge. If you love your job and if you don't want them to hire someone who would be willing to do the things that they like, you better do what they assigned to you IF you think you can still do it.

It is only appropriate to say no if it is going to affect your well being in a negative way. Unfortunately many employers get away with having people do the jobs that they were never meant to do in addition to their own. It is even more prevalent with lay offs that more people are having to clean up their own desk areas, and do more paperwork tasks than were originally called for in their job description. If you are looking for a new job, sure... say you won't do what they ask because they will find someone else who is willing to do the jobs, and other jobs not in the description, for less pay.

If you do not like doing it, say no. If you find you are making mistakes, say no. If it is endangering your health and your sanity, say no. If it is beyond your scope and expertise, say no. Otherwise you will find yourself in some kind of breakdown. I know I did. I tend to be flattered by the challenges management gives me, and then I get overwhelmed, because I am not superwoman, and I totally have to quit work completely and recover. That is when I spent three months taking a daily nap as I mentioned in another discussion. I am going back to the company I worked for two and a half years ago, but I am limiting my hours and involvement.

Good day Eucalyptus, Practically speaking, it is really hard to refuse and say no on a task that is being given to you. Especially if you are only a staff or a subordinate. That, although you are aware that it is not really a part of your job description, they will still demand that you do the task. And this is the reason why they always include the last part of your duties, function and responsibilities - "Perform other duties assigned from time to time.". In this part/section, the management has the power to put added workload towards their employees. Hence, the generality of the statement cannot really define the additional task being given. So, they can inject another duty that their staff/subordinate should do. And as the word implies, "other duties assigned from time to time", meaning, other duties which can be beyond to your specific duties/task.