Image of bags of Rock Salt

F.A.Q. Rock Salt

The MCMUA operates one of NJ's most comprehensive household hazardous waste (HHW) programs. This F.A.Q. page and information on hazardous materials is intended as a guide about HHW materials as well as the MCMUA's HHW program. This information is a general guide and does not constitute official rule, regulation or law.

There are two common types of rock salt that are described below. These rock salts are used to melt snow and ice in the winter. They are also commonly used in water softeners. Both types of rock salt are considered hazardous and are acceptable materials at the Household Hazardous Waste Disposal Facility in Mount Olive Township or at one of the MCMUA household hazardous waste disposal days.Photo of Halite

  1. Sodium Chloride – a/k/a Halite; is non-hazardous but will react with strong acids to generate HCl and strong oxidizing agents to generate Cl2.
  2. Calcium Chloride – This material is Dangerous When Wet.  Therefore contact with water generates heat. In the presence of moisture, the material is corrosive to aluminum, zinc and tin, producing highly flammable hydrogen gas.  Keep away from acids; gives off heat

Note: Crystal solar salt specifically for softening water is not considered hazardous and should be discarded with the regular garbage. If you are removing a water softener with a slurry of this crystal salt mixed with water, drain the water from the mixture and dispose of the solids in the garbage.