It is generally best to use a high purity sodium chloride such as Culinox® 999® salt or Reagent Grade Sodium Chloride. These contain a minimum of 99.9% Sodium Chloride and additives. Using this salt will reduce the incidence of inconsistent test results due to impurities or other additives. For more information, see ASTM Method B117-03 Standard Practice for Operating Salt Spray (Fog) Apparatus. Other variations for salt spray testing may also be found at the ASTM website at https://www.astm.org
