Most safety rules and procedures are just plain common sense. Laminators are enclosed mechanisms for the most part, so the possibilities of harm come from malfunctions, sticking things in holes, and environmental issues.
Laminators are intended to be used indoors!
For all electrically-powered laminators, inspect the power cords frequently and don't use the machine if they look frayed or damaged; don't use the machine at all if it has been wet; unplug it if not in use for any long period. Likewise, smoke or an excessive sensation or odour of heat is not good. Turn the machine off immediately and investigate.
For home, school, and small office use, make sure that only people who know what they are doing operate the machine. Place it in a corner or other location where access can be controlled. Laminators do not produce the sort of horrifying injuries that shredders do if someone pokes around inside, but it can still be a nasty situation - severe burns or squashed fingers - so keep children or pets away. Remember that loose clothing can be caught and pulled into the machine. Buy a cabinet big enough to hold the laminator and lock it away out of hours.
Do not poke anything into the machine: do not allow anything on the input shelves other than film and the materials to be laminated; make sure that nothing larger than the limits for the machine gets into it.
For industrial-use laminators, setting up a proper environment is imperative. This includes adequate power, environmental conditioning of the operating area, safe storage for film and other supplies, fire extinguishers, etc. There may be legal concerns - such as hazardous material regulations and operator certification - to comply with. Consult with experts before going into production.
Finally, for all kinds of laminators, apart from the very simplest cleanings (see the article on maintenance), do not attempt service or repairs unless someone is certified to do it.