1 Air or Gas 2 Aerated 10 Calcium Treated 11 Caustic ( High pH ) 20 Gel 21 Gyp 30 Invert Oil Emulsion 31 Lime 32 Low pH 40 Mist or Foam 50 Natural 60 Oil Base 61 Oil Emulsion 62 Organic 63 Organic Treated 70 Phosphate 71 Polymer 72 Potash 80 Salt Water 81 Salt Water - Lignosulfonate 82 Salt-Polymer 90 Water 99 Miscellaneous