AnswerYes you'll be fine dont put it on any electronic parts though you can use 3 and one in just about any situation it has good viscosity for many uses
I used to have a Xerox shredder, and only vegetable oils were to be used on it. Mineral oils, like 3-in-1 oil, are more likely to swell the plastic of the shredder, causing damage.
No, I work for customer service for Fellowes it is not ok to 3-in-1 in the shredders you always need to use a vegitable based lubricant/oil you can even use vegetable oil from your kitchen the only difference being that the oil from your kitchen has no perseverance in it so the oil will go bad and make a bad smell in your shredder.
You can also use a synthetic oil like Paslode's Impulse oil or Singer Sewing machine oil. I both cases they are for high rpm and will not gum up.