Canned air and your copier or printer:

I occasionally visit offices that either have canned air or ask me about using it in their equipment.
My feelings are that if you do utilize it, use caution! There are areas of your equipment that are acceptable such as (removable paper drawers) for it’s use, and other areas (most everywhere else) that are not. If it is an area where photo sensors, or optics are located then I would say no. Generally just blowing canned air or other compressed air into your equipment only moves paper dust and toner into areas where it may cause more harm than good. If you see dust it does not mean it’s causing or even will cause a problem. Using compressed/canned air improperly can cause future breakdowns and premature parts failures, like clutches, bearings, motors, and charging components.
My recommendation is to have an experienced technician decide how and when to remove toner, dirt, and other dust. The best way is usually with a specifically designed vacuum for using in and around copiers and printers. They will not likely damage electronic parts or printed wiring boards because they are grounded throughout to prevent static charges from harming your equipment. These “high tech” vacs also have higher levels of filtration than many other standard vacs so your office airspace should not become full of airborne toner particles when in use.