Use de-icing products with caution

OLATHE, Kan. – The sleet and snow has quickly reminded us of winter’s harsh conditions. Slick driveways and sidewalks are a safety hazard. Several people have slipped and fallen on icy sidewalks this past weekend. But chipping and shoveling is more work than many of us want to undertake. Those looking for an easier method of removing ice and snow often resort to the use of de-icing compounds. Hardware stores have experienced a run on these products. While these products are effective, they should be used with caution. Many of these products have side effects that damage plant materials and concrete. Some are corrosive to metal, and even worse, can pollute the water.

There are about five main materials that can be used as chemical de-icers. These include calcium chloride, sodium chloride (salt), potassium chloride, urea (a fertilizer), and calcium magnesium acetate.

Calcium chloride is one of the most frequently used materials for road and highway de-icing and it is very effective. It is usually not damaging to plants unless high amounts are applied.

Sodium chloride and potassium chloride can cause serious plant injury when washed or splashed around plants. Foliar and root injury occur when excessive amounts of these materials are used. Often this damage does not appear until the following spring. Root damage is more common when there is not adequate rainfall to leach the chemicals from the soil.

Urea, a common lawn fertilizer, is good for melting ice. It normally does not damage plants unless applied at very high rates. However, it can damage concrete and metal surfaces. Often usage of fertilizers as de-icers result in lush plant growth around the areas they were used come spring.

Calcium magnesium acetate is made from domolitic limestone and acetic acid, which is a common compound found in vinegar. It shows little effect on plant growth and concrete surfaces. It does not form a brine solution like other products, but keeps the particles from bonding together. It is effective to about 20 degrees.

Limited use of any of these products should cause little plant injury. Problems occur when they are used excessively and there is not adequate rainfall to wash or leach the material from the area. Since limited use is recommended, it is best to remove the ice and snow by hand when possible. When chemicals are applied, practice moderation. We are often prone to over- applying just to make sure the ice and snow melt. Keep in mind this can damage concrete surfaces as well as the plants and grass growing along the walks and driveways. These problems are normally latent and will not show up until spring or summer.

Source: Kansas State Research and Extension