Para Sour 100 Lbs. Drum [Pariser]Para Sour R Para Sour R is an effective neutralizing Sour product that has excellent rust removing capability. Product has direct application where final pH of linen is required below the range found in the raw water used for rinsing, and where rust or iron matter is prevalent in same. Ammonium bi fluoride in nature, Para Sour R is extremely soluble in all water temperatures. Application Para Sour R is used in the range of 1 2 ounces per 100 pounds of