by David Mrazek
La Grange Park Sustainability Commission
Winter is here! And winter usually means snow. And snow inevitably means dangerous ice on our sidewalks.
Your first thought may be to go buy rock salt, but it's important to know that the stuff has its drawbacks. Yes, rock salt, the mineral form of sodium chloride, effectively melts ice, but it's also toxic. It sticks around and once the temperatures rise, can burn your grass and stress the plants in your garden. Dissolved salt can contaminate ground water and nearby streams and rivers. (It upsets the pH of the water - not good for the overall ecosystem.) Rock salt is also harmful to pets and their sensitive paws and is lethal if ingested.
There are a lot of alternatives to rock salt, but the choices and claims made by the products can be confusing. I've done some research and have narrowed things down to the list below. These selected options are easier on the earth, though several still have caveats to consider. Most of the chloride products can damage different types of concrete over time and the salt residue can get tracked inside. Note to pet owners: If you really want to protect your pet, buy non-toxic brands that contain no chloride. But keep in mind their melting capabilities are not as effective as some of the chloride products. As a comparison to the products below, rock salts melts ice to about 15 or 20 degrees Fahrenheit, (F). Also, for best results remember to apply any deicer an hour or two BEFORE the anticipated snow.
1. Calcium Magnesium Acetate. Known as CMA, this product works effectively to 20 degrees F. and is extremely effective at melting ice while requiring fewer applications. It is considered safe around children, pet's paws and won't damage concrete. CMA is considered to have less overall harmful impact than other de-icers, but it is more expensive.
2. Calcium Chloride. This is the most reliable melting product available, able to work down to -25 degrees F. But it can be harmful to your pet's paws and is poisonous if ingested by your pet. It can cause minimal to moderate damage to asphalt and concrete, and if you over apply, it can damage grass and plants.
3. Potassium Chloride. With an effective temperature of 12 degrees F. it is a bit more expensive than some of the other choices. But it is less damaging to asphalt and concrete and is safer for pets and gardens.
4. Magnesium Chloride. Effective down to 5 degrees F. this is now available in pellet form, and is a safe, highly effective alternative to rock salt. Derived from sea salt, it's an all-natural ice melting material and environmentally friendly. It's safer for pets and when used as directed will not harm plants. There is conflicting information about how much it damages concrete over time.
5. Pet Safe Brands. These products contain no chloride and are completely safe for pets. But, big surprise, they are more expensive: Morton Safe-T-Pet and Paw Thaw claim to melt down to 10 degrees or more. Safe Paw Ice Melter claims to melt down to -2 degrees F.
6. Sand or Plain Kitty Litter. These are cheap options that help create traction for walking, but they won't melt ice. Combine sand or kitty litter with another melting product like calcium chloride to actually melt the ice on your walkway.
7. Homemade Remedy. Mix a teaspoon or two of Dawn dish soap, a quart to half-gallon of lukewarm water with a tablespoon of rubbing alcohol. A Pennsylvania news reporter claimed this concoction melts ice almost immediately.
For even more detail, check out this handy comparison chart from Consumer Reports.