The Arm & Hammer Baking Soda Fridge Fresh Air Filter keeps your fridge smelling fresh by absorbing and deodorizing food odors. Ideal for maintaining food freshness longer. Pure & Natural Free from harsh chemicals Eliminates odors Keeps food tasting fresh longer Absorbs & deodorizes food odor Change every 30 days Key Material: Box/housing (Cardboard/Plastic); Sodium Bicarbonate (NaHCO3?) powder. (Used for odor absorption).Arm & Hammer: Trusted for pure and natural cleaning solutions, free from harsh chemicals.Remove packaging wrap and place the open unit in the refrigerator to absorb odors. Replace regularly.Household Use Only. Not for ingestion.