Original: At a concentration of 23.3%, the freezing point of NaCl brine is lowered to 21 C (252.15 K, 6 F), and that of CaCl2 brine down to -40 C (233.15 K, -40 F).
Simplified: At 15.5 Celsius, a saturated solution of brine can hold 26.4% salt by weight.