How long does Kilz smell bad?

How long KILZ smells bad depends on which KILZ product you use, ventilation, temperature, and humidity, as different formulations have very different odor levels and dry times. KILZ Original oil-based primer has strongest and longest lasting odor because it contains petroleum solvents; it smells strongly during application and can smell bad for 2 to 4 hours during drying, with residual solvent odor lingering 24 to 48 hours in enclosed spaces without ventilation, and fully dissipating after 3 to 7 days after topcoating, though sensitive individuals may detect odor longer. KILZ 2 All-Purpose latex primer has much milder odor, smells like typical latex paint, and odor usually dissipates within 1 to 2 hours with ventilation and is gone by 24 hours. KILZ 3 Premium latex has similar low odor, gone in few hours. KILZ Restoration water-based but high odor blocking has moderate odor during application, stronger than latex but less than oil, dissipating within 4 to 8 hours. Zinsser shellac based has strong alcohol odor but dissipates quickly within 1 hour. To reduce KILZ smell, open windows, use fans, keep temperature 70 degrees and humidity low, and apply topcoat after primer dries per label, usually 1 hour for latex and 1 hour for oil. Oil-based KILZ smell can be minimized by using respirator with organic vapor cartridges. Most people find smell tolerable after 24 hours.