Initially, spray foam insulation does put off gas and odor. Spray foam is an inert cellular plastic that is manufactured on-site by trained contractors.  Like all plastics, there is an odor during manufacturing.  The majority of this “off-gassing” period lasts about 24-hours; a period during which the manufacturer suggests occupants should vacate the area.  After 24 hours, the spray foam becomes fully cured and occupants are permitted to re-enter.  Some people with an acute sense of smell may notice a slight odor for a short time after curing, especially with open-cell foam, but this is normal.