What is the Difference Between Rock Salt and Magnesium Chloride?

The Duke Company receives many questions regarding deicers, snow removal and construction rental equipment. One of the most common is what is the difference between rock salt and magnesium. 


Rock Salt vs Magnesium Chloride

Deicers/ice melts are not the same. They all lower the freezing temperature of water, but their capabilities and performance vary based on the chemical composition. Both rock salt (sodium chloride) and magnesium chloride contain chloride.

Rock Salt

Rock salt has been referred to as sodium chloride, NaCL, or Halite. It is absorbed into water forming a brine. The brine has a lower freezing temperature than water and consequently melts surrounding ice and prevents ice formations.

  • rock salt performs at its best between 15-20 degrees Fahrenheit.
  • easily accessible
  • affordable
  • Rock salt can have an adverse impact on the environment. As such, it is important to keep in mind the manufacturer’s  specifications.
  • Overspreading the material will not improve the performance of rock salt. The excess can come into contact with vegetation when it washes away with melted snow/ice. The exposed vegetation can dehydrate the plants and the pH of the soil can be altered.
  • Spreading the proper amount can prevent this. An additional considerations are pets. Deicers with a CMA coating can protect your pet’s paws.


Magnesium Chloride
  • Magnesium chloride is considered to be safer for around plants, pets and concrete surfaces. 
  • It is very effective and fast acting. Magnesium Chloride absorbs moisture quickly, forming brine quickly, thus starting the melting process more quickly.
  • It functions in temperatures below 0 degrees Fahrenheit.
  • It leaves very little residue behind, useful for areas with high foot traffic.
  • Some Magnesium Chloride products are coated with CMA to provide added protection for animals and children.
  • Magnesium chloride is more costly than rock salt.
  • It requires additional applications because the brine solution becomes diluted more quickly than the brine solution formed from rock salt.


In Summary
  • Smaller property owners, or those that own pets should consider a magnesium chloride based product.
  • Rock salt may be a better solution for large areas.


Call the Duke Company‘s expert customer service to help you decide which product best suits your needs and budget.

585-292-9870  (Rochester NY), or 607-347-4455  (Ithaca NY).
Likewise, you can place an order via our web portal for a quick quote.


We have best values on Rock salt, snow/construction equipment rentals. In addition to carrying a variety of deicers and snow removal equipment, we also carry construction equipment rentals 


We proudly carry: American Rock Salt in bulk, wholesale, pallets and convenient 50 pound bags. 

American Rock Salt is known and respected by Ice Control experts for its exceptional characteristics including:

  • Comprised of 100% natural Sodium Chloride (NaCL).
  • Also known as Halite and Road Salt, is part of the inorganic salt chemical family.
  • Crystalline solid is white and off-white, and has no odor.
  • Safety note:   American Rock Salt complies with the Toxic Substance Control Act.
  • Use common sense when handling Rock Salt & Road Salt by wearing eye protection, breathing protection and avoid contact with your skin.
  • While naturally occurring, Rock Salt should NOT be ingested.
  • To avoid caking, store Rock Salt in a dry area with less than 75% humidity.
  • 100% mined in the USA at the American Rock Salt mine located in Hampton Corners, south of Rochester New York.
  • Download Helpful MSDS & Product Information: 

    MSDS Material Safety Data Sheet for Rock Salt Bag



We also carry Stop Ice Melt with Quad Action Melting Power


stop ice pic

Stop Ice Melt with Quad Action Melting Power (manufactured by the Kissner Group) is widely respected by Ice Control experts for its effectiveness and exceptional characteristics including:

  • Widely respected 4-way Ice Melter
  • Quad action melting power leverages advanced ice melting characteristics of Sodium Chloride, Calcium Chloride, Potassium Chloride and Magnesium Chloride.
  • Works capably in melting ice and snow to negative 12 degrees Fahrenheit.
  • Use common sense when applying.  Protective clothing is not required.
  • Formulated to reduce corrosive damage to automobiles and other equipment.
  • Melting extenders result in very durable and long-lasting melting power.
  • Less harmful to plants, vegetation, wood and concrete than many competing products.


Call theDuke Company at585-292-9870 (Rochester NY) and607-347-4455(Ithaca NY) formoreinformation, business hours, andall your snow and ice removal needs and information. 


Sign-up for the Duke Company’s Rock Salt & Deicer Alerts

Text ‘DUKESALT’ to 55469 to receive text messages regarding our hours, extended hours, schedule changes and discount opportunities.

Industries we serve:

Building Maintenance
College Campuses
Car Wash
Equipment Rental
Grocery Retail / Wholesale
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Hospitals / Nursing Homes
Janitorial Supplies
Landscape Maintenance
Lawn & Garden Centers
Mass Merchandisers
Parking Lot Maintenance
Portable Toilets
Property Management
Schools / Universities
Snow Removal
Transportation / Airports

By DavidSzydlowski

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