On an icy day, spreading rock salt on your front walk could mean the difference between securely getting to your car and ending up in the emergency room after a bad slip and fall. The mineral halite, commonly known as sodium chloride, or NaCl, is also known as rock salt. Municipalities and individuals alike use it to keep roads and sidewalks from becoming icy. What occurs next when you sprinkle rock salt on a slick sidewalk is due to chemistry.

Silky Terrier Dog Breed Playing Aro... Silky Terrier Dog Breed Playing Around

Pure water has a freezing point of 32 degrees Fahrenheit, however, a salt and water mix has a lower freezing point. Water will freeze on touch and form ice if the ground temperature is below 32 degrees. The sun’s heat or friction from people’s feet or car tires melts the ice enough for it to mix with the salt and form slush when rock salt is sprinkled over it. Because slush has a lower freezing point than pure water, it will not change back into ice unless the temperature drops still further. In the winter, towns and individuals can use a variety of products to treat icy roads and walkways.

Salts that melt ice and snow and are safe to use at home are available. If they don’t have rock salt on hand, some people make their homemade ice melt to deal with slick surfaces. While rock salt is normally quite effective, different types of salt may cause ice to melt faster, so weigh all of your alternatives before making a decision. Table salt does not expire or spoil. Rock salt doesn’t do either, so it’s not necessary to get rid of it just because it’s old. You can keep a sealed jar of rock salt for many years and it will still be effective when you reopen it. If you do need to get rid of leftover rock salt, you can do it with the regular trash.

Do not put rock salt onto your bushes or other vegetation as a means of disposal. Salt is toxic to plants, thus sprinkling it over a plot of land will kill everything growing there and make it unlikely that anything will grow again. Unless your town specifies otherwise, shoveling leftover rock salt into a garbage bag and depositing it in your trash cans is your best chance.