Protecting workers from overspray may involve respirators, gloves, training programs, even medical exams. These approaches take time and money, and sometimes worker health is still jeopardized.
Controlling overspray is doubly important. Solving worker exposure problems has implications for supervisors, workers, managers, engineers, and suppliers. Because there are so many coatings and types of spray equipment in use, it's difficult to make specific recommendations. Instead, OSHA covers basic avenues of approach to control of health hazards.
If you're using coatings that contain hazardous substances, first consider switching to safer ones. In recent years the number of different paint formulations available has increased dramatically. There may be alternatives to what you are using that are just as good. Maybe better. All coating ingredients are used because of specific properties, and there are tradeoffs in any switch.
Some chromate substitutes sacrifice color, match, cost, and durability. But the automobile and shipbuilding industries are currently interested in metal primers that contain metallic zinc dust in place of zinc chromate. It protects metal by galvanizing it rather than merely inhibiting rust. Unlike zinc chromate, it is of low toxicity.
Powder coatings have been developed in part to eliminate the use of hazardous solvents. They require the use of special equipment, but they have low energy consumption and will build a heavy coating in a single pass.
The appliance industry is currently the heaviest user of powder coatings. Water has been successfully used in some situations to replace many of the organic solvents. Water-borne coatings, as they're called, are much less hazardous to painters.
There are no completely safe coatings. Selection of one or another is complicated, and you may need help with that decision. Paint suppliers are one resource.
The National Paint and Coatings Association in Washington, D. C. can give general information about coatings and their health effects. But the best resource for specific recommendations may be an industrial hygienist or other health professional in your area.