If you plan to use rattle cans more than airbrushes, you may want more exhaust fan volume. If you use both methods, you may want to increase the fan capacity to compensate for spray can use. Finally, remember to use a fan motor that does NOT use brushes on the electric motor. Brushes in an electric motor can produce significant sparks that can be highly dangerous when used around flammable paints, regardless of whether the paints are from spray cans or airbrush devices. Many builders use fans from computer equipment cases because they usually use brushless motors in those applications.
Many paints produce volatile and toxic fumes.
Fire hazards and personal health risks are always present. Filter elements clog after prolong use, so clean or replace the elements as needed. Following safety guidelines along with common sense will reduce the hazards when it comes to painting your models. Trying to save a few bucks or ignorance is never reason to endanger yourself and your family. Another fine piece of info from the Straight Line Modeler's Group.