VOCs can cause lightheadedness, headaches, nausea, irritated eyes and throat, and respiratory issues. This can be an even greater hazard for those with compromised immune systems. Exterior and interior paints are vastly different, so you shouldn’t combine them. It compromises the quality of both paints. Plus, exterior paint isn’t designed to look good inside. Both varieties of paint are highly specialized, and you’ll likely regret using them where they are not intended.