Calcium chloride is a salt of calcium and chlorine. It is used in salt-water aquariums and on roads to melt ice. It is generally not hazardous and can be disposed of in the trash or down the drain.
Calcium chloride gives off heat when dissolved in water. Calcium carbonate can irritate eyes, skin and upper respiratory tract and can be harmful if ingested.
If calcium chloride is disolved in water, dilute it down to one percent or less (a ratio of one part calcium chloride to 100 parts water).
Turn on the faucet and let the water run for one minute. Pour the diluted solution down the drain and follow with water for five minutes.
Dispose of solid calcium chloride, in amounts less than 2 kgs (about 4.5 lbs.), in the trash. Check with local authorities for specific regulations dealing with calcium chloride. Most places have no restrictions for its disposal.