Governor Pat Quinn signed the bill Monday that allows schools to stock and use epinephrine shots, which deliver medicine to children having severe allergic reactions.
Quinn signed the law at Edison Regional Gifted Center in Chicago, where a 13-year-old girl died last year after having a severe reaction to peanuts.
The most common food allergens are peanuts, milk and shellfish.
Attorney General Lisa Madigan joined Quinn for the signing.
The law goes into effect immediately. It lets school officials stock EpiPens and administer the shots without fear of liability.