What are the long term side effects of dry ice?

The extreme cold makes the solid dangerous to handle without protection due to burns caused by freezing (frostbite). While generally nontoxic, the out gassing from it causes asphyxiation due to displacement of oxygen in confined locations. Prolonged exposure to dry ice can cause severe skin damage through frostbites, and the fog produced may also hinder attempts to withdraw from contact in a safe manner. Because it sublimates into large quantities of carbon dioxide gas, which could displace oxygen-containing air and pose a danger of asphyxiation, dry ice should only be exposed to open air in a well-ventilated environment.[ Industrial dry ice may contain contaminants that make it unsafe for direct contact with foodstuffs.