Liquid Ammonium Sulfate (LAS) has become widely accepted as a stable and effective source of ammonia for chloramination.  Alternatives such as anhydrous or aqueous ammonia are hazardous, requiring pressurized storage tanks as well as special handling and safety procedures. 

LAS can be metered to deliver a precise amount of ammonia.  The LAS chemical replacement ratio for anhydrous ammonia is 10:1, providing a chlorine to ammonia ratio of 3-5:1.  However, replacement ratios of less than 10:1 have been achieved with LAS due to its chemical efficiency.  Unlike the alternatives which experience vapor loss, all of the ammonia in LAS remains bound in solution until it contacts chlorine.

Description

Liquid Ammonium Sulfate (LAS) is a stable, non-toxic, non-irritating liquid.  It is sold as a 30-40% aqueous solution of ammonium sulfate, based on a NH₃ content of approximately 10% with a range of 9.8-10.3%.  Density of the solution is 10.1-10.3 lbs/gal and a resulting pH of 3.0-5.0.  The formula for dry ammonium sulfate is (NH₄)₂SO₄.