The use of dry solid chemicals as an anti-icing treatment can be effective in many circumstances, but only where there is sufficient moisture or accumulation of snow or ice on the pavement. Moisture must be present for two reasons:

For initial operations, solid chemicals will be effective when maintenance forces have the operational resources available to apply the chemical soon after sufficient precipitation has fallen, but before ice bonds to the pavement. For subsequent operations, solid chemical treatments will usually be effective when there is adequate moisture or accumulation of snow or ice during later periods of storms. There must also be sufficient traffic volume to keep the material mixed and allow it to go into a solution.

For either initial or subsequent operations, when there is not enough moisture or accumulation of snow or ice on the pavement there is likely to be loss of the chemical from the pavement. This may be caused by the blowing action of traffic, especially from high speed and commercial vehicles, or by particles bouncing off the pavement during spreading.