Rock salt used for ice removal shall be produced by crushing natural deposits of sodium chloride. Material produced by recrystallization of salt solutions will not be accepted. CHEMICAL COMPOSITION. The rock salt shall conform to the following requirement as to chemical composition: Sodium Chloride (NaCl) Minimum percent.................95.0. GRADING. The rock salt shall conform to the following gradation requirements as determined by laboratory sieves: (U.S. Standard Sieve Series) Sieve Designation Percent Passing 3/8 inch.... 100 No. 3....95.0 Minimum No. 8....35.0 Maximum No. 30....15.0 Maximum. PACKAGING AND MARKING. The rock salt shall be delivered in bags or sacks containing not more than 50 pounds each or in bulk when requested. When delivery is made in bags or sacks, the name of the manufacturer and net weight shall be legibly marked on each container. The percentage of sodium chloride guaranteed by the manufacturer shall be noted on the shipping report or legibly marked on the containers. When delivery is by bulk, the manufacturer shall furnish certified analysis giving guaranteed sodium chloride content of the rock salt furnished. SAMPLING AND TESTING. The rock salt shall be sampled and tested in accordance with A.S.T.M. Designation: D 632-99. If the material is sampled after delivery, it is understood that a 0.5 percent variation in content of sodium chloride from the chemical composition prescribed in Section 3 shall be permissible. REJECTION. The rock salt shall be rejected if it fails to conform to any of the requirements of these specifications. The material shall be rejected if not received in a free flowing usable condition. Two types of calcium chloride are covered as follows: Type 1 - Regular flake calcium chloride. Type 2 - Concentrated flake, pellet or other granular calcium chloride. CHEMICAL COMPOSITION. The calcium chloride shall conform to the following requirements as to chemical composition: Type 1 Type 2 Ca C12, Minimum percent....77.0 90.0 Total alkali chlorides (as NaC1), Maximum percent....2.0 5.0 Total magnesium (as Mg C12), Maximum percent.... 0.5 0.5 Other impurities (not including water) Maximum percent.... 1.0 1.0. GRADING. The calcium chloride shall conform to the following requirements for particle size, when tested by means of Laboratory sieves: (U.S. Standard Sieve Series) Sieve Percent Passing 3/8 inch ...100 No. 4 ....80 Min. No. 20 ....10 Max.
