Calcium chloride is hygroscopic, meaning it attracts moisture from the air and its surroundings. It also has high surface tension, low vapor pressure, and a strong moisture film, which, combined with its thirst for moisture, help to bind aggregate particles together. Along with this binding effect, calcium chloride makes the treated roadway stay slightly damp, thus reducing dust.

Unpaved surfaces, treated with calcium chloride, remain compacted. Over time, the chemical penetrates the surface several inches, further stabilizing the entire road base to reduce frost damage, erosion, and overall wear. Applied properly, calcium chloride poses no environmental concerns.

For dust control on unpaved roads, 38% calcium chloride is applied at the rate of 0.27 gallons per square yard. To obtain a 38% concentration of calcium chloride in water requires 4.51 pounds of DOWFLAKE* per gallon, so the dust control application rate for DOWFLAKE (in solution) is 1.5 pounds per square yard. Recommended application rates vary depending on the road’s use and volume of traffic.
 
Products recommended for dust control:
DOWFLAKE 77-80% calcium chloride