Home › Learn › Deicing

Calcium nitrate as a deicing agent, and how it compares with every other common deicer

Last updated: 7 October 2026  ·  Reviewed by Sujay Shrivastava - Digital Transformation Consultant
In summary

Calcium nitrate is a niche, chloride-free deicer, not a mainstream one. Russian laboratory work (Kurnakov Institute) mapped the Ca(NO3)2–water freezing behaviour from 0 to −31 °C and reported no attack on metals, aircraft alloys or cement concrete, recommending anhydrous granular calcium nitrate for runway pavements.[2] The mainstream deicers are still sodium chloride (eutectic −21 °C), magnesium chloride (−33 °C), calcium chloride (−51 °C), calcium magnesium acetate (−27.5 °C) and potassium acetate (−60 °C),[1] plus glycols for aircraft.[11] The honest drawback of calcium nitrate is nitrogen: it adds nitrate to runoff, and deicer patents and extension guidance treat nitrogen salts as environmentally undesirable.[14][16] It is not named in the FAA or Transport Canada runway-chemical specifications we reviewed.[7][9]

Key facts at a glance

ItemValue / answer
What deicers doDissolve in the water film on ice to form a brine whose freezing point is lower than that of water, so the ice melts[16]
Calcium nitrate: studied rangeCa(NO3)2–H2O equilibrium and ice crystallisation mapped from 0 to −31 °C; minimum effective temperature determined experimentally[2]
Calcium nitrate: corrosion (lab study)Solutions reported not to attack metals, aircraft alloys or cement concrete[2]
Calcium nitrate: recommended formAnhydrous granular, for cement-concrete and asphalt-concrete runway pavements (authors’ recommendation)[2]
Calcium nitrate: main drawbackNitrogen load to runoff; a deicer patent calls nitrate inclusion “potentially damaging to the environment”[14]
Drinking-water limit for nitrateEPA maximum contaminant level 10 mg/L (as nitrogen)[18]
Sodium chloride eutectic−21 °C at 23.3% concentration[1]
Calcium chloride eutectic−51 °C at 29.8%[1]
Magnesium chloride eutectic−33 °C at 21.6%[1]
Calcium magnesium acetate (CMA) eutectic−27.5 °C at 32.5%[1]
Potassium acetate eutectic−60 °C at 49%; sold as roughly 50% liquid with corrosion inhibitors[1]
Practical lowest working temperature, Ontario briefNaCl −9 °C, MgCl2 −15 °C, CaCl2 −29 °C, CMA −7 °C[17]
Most-used U.S. airfield pavement deicerPotassium acetate, about 80% of airfield deicing chemical use in EPA’s survey[11]
Chloride criteria for freshwater life (EPA)230 mg/L chronic, 860 mg/L acute[19]
Zeolite + calcium nitrate product (example)Retailer lists a chloride-free anti-slip deicer rated for 0 to −15 °C (vendor claim)[22]

Is calcium nitrate a deicer?

Yes, but a specialist one. Any soluble salt lowers the freezing point of water, and deicers work by forming a brine on the ice surface.[16] Calcium nitrate is highly water-soluble,[24] so it qualifies on chemistry. The published evidence is thin and concentrated in one research group: the Kurnakov Institute of General and Inorganic Chemistry (Russian Academy of Sciences), which studied the Ca(NO3)2–water system from 0 to −31 °C, built the ice-crystallisation curve (polytherm), calculated the ice-melting capacity under equilibrium conditions, and measured corrosion of metals, alloys and cement concrete.[2] The same group also described deicers based on magnesium and calcium nitrate mixtures, including a liquid solution and a solid dehydrated composition, and noted that the liquid form needs a corrosion inhibitor to bring metal corrosion down.[3]

We found no calcium nitrate entry in the Transport Canada runway ice-control advisory circular (which points to SAE AMS 1431 and AMS 1435 products)[7] or in the Wikipedia overview of road and runway deicers.[23] Treat it as a niche or emerging option, not a standard purchase specification.

What are the common deicing agents and products?

Deicing chemicals fall into a few families: chlorides (sodium, calcium, magnesium), acetates and formates, urea, glycols for aircraft, agricultural by-products such as beet juice, and a small group of nitrates.[16][17][23] The table below compares them. Eutectic values are the theoretical lowest temperature of a brine at its best concentration;[1] real-world “lowest practical working temperature” is always warmer, which is why the Ontario conservation-authority brief lists NaCl at −9 °C although its eutectic is −21 °C.[1][17]

DeicerEutectic / practical lowCorrosion and infrastructureEnvironmentCost tierWhere used
Sodium chloride (rock salt)−21 °C eutectic;[1] −9 °C practical[17]Harms plants, soil and concrete; pitting of sidewalks[16]Chloride is persistent; EPA freshwater criteria 230/860 mg/L[13][19]$ (lowest)[17]Roads, sidewalks; the default[16][23]
Magnesium chloride−33 °C;[1] −15 °C practical[17]More corrosive than NaCl to vehicle parts in humid conditions;[6] chemically attacks cement paste[4][5]Adds chloride[17]$$[17]Anti-icing brines, pre-wetting[17]
Calcium chloride−51 °C;[1] −29 °C practical[17]Highly corrosive to concrete; forms calcium oxychloride at high concentration (above about 15% by mass)[4][16]Adds chloride[17]$$$[17]Cold-weather roads, liquid brines[17]
Calcium magnesium acetate (CMA)−27.5 °C;[1] −7 °C practical[17]A corrosion inhibitor, less corrosive to concrete[15][16]Beneficial to most soils,[15] but can raise biological oxygen demand[17]$$$$; up to 40 times NaCl[16][17]Sensitive sites, bridges; limited by price[17]
Potassium acetate−60 °C[1]Commercial liquids carry corrosion inhibitors[1]Organic; lower oxygen demand than urea[7]High; judged too expensive for general road use[17]Airfield pavements, about 80% of U.S. airfield use[11]
Sodium formate, sodium acetate, potassium formateOrganic-salt class, effective at lower temperatures than urea[7]Potassium formate was linked to Boeing 737 wheel-well connector corrosion; the Canadian warning was later cancelled[7]Lower oxygen demand than urea[7]Higher than salts (organic-salt class)[7]Airfield pavements (AMS 1431 solids)[7][11]
UreaAbout −7 °C practical[7]Low-temperature effectiveness limited[7]High oxygen demand; EPA requires large airports to use non-urea deicers or meet an ammonia limit[7][10][12]Low (in decline)Legacy airfield use, 4,127 tons/yr in EPA survey[11]
Propylene and ethylene glycol fluidsAircraft Type I and IV fluids[11][25]Formulated with corrosion inhibitors[11]Very high oxygen demand when degrading[11]SpecialtyAircraft only; propylene glycol is about 77% of Type I use[11]
Agricultural by-products (beet juice etc.)−17 to −23 °C practical[17]Not corrosive[17]By-product origin; used to boost salt[17]Varies[17]Pre-wetting, anti-icing[17]
Calcium nitrateStudied 0 to −31 °C[2]Reported not to attack metals, aircraft alloys or concrete (lab study)[2]Chloride-free, but adds nitrate[14][16][18]Not establishedNiche; research stage; runway pavement recommended in the study[2]
Zeolite + calcium nitrate (anti-slip blend)0 to −15 °C, vendor claim[22]Vendor claims anti-corrosive[22]Vendor claims chloride-free[22]Retail productWalkways, small areas; example only[22]

Cost tiers marked $ to $$$$ follow the Ontario brief, which ranks NaCl lowest and CMA highest;[17] we could not find a published price for calcium nitrate as a deicer and do not state one. The NCHRP Report 577 guideline evaluates snow and ice control materials on cost, performance, and impacts on the environment and infrastructure, and is the standard framework for road agencies to follow.[20]

How cold can each deicer work?

The FHWA anti-icing manual lists eutectics of −21 °C for NaCl, −33 °C for MgCl2, −51 °C for CaCl2, −27.5 °C for CMA and −60 °C for potassium acetate.[1] The same manual advises making sodium chloride anti-icing brine “as close to 23.3 percent as possible, but no more than 25 percent”.[1] The Ontario brief gives lower practical limits (NaCl −9 °C, MgCl2 −15 °C, CaCl2 −29 °C, CMA −7 °C).[17] For calcium nitrate, the Russian study states that the minimum effective temperature was determined experimentally but the abstract available to us does not give the number, so we do not quote one; the equilibrium was measured down to −31 °C.[2]

Is calcium nitrate corrosive or damaging to concrete and aircraft?

In the Kurnakov study, calcium nitrate solutions did not attack metals, aircraft alloys or cement concrete, and that is the main reason the authors recommend it for runways.[2] Compare chlorides: magnesium and calcium chloride react with cement paste, with calcium oxychloride forming at concentrations typically above 15% by mass,[4] and the type of deicing salt strongly changes the type and extent of chemical damage in slag-cement pastes.[5] Magnesium chloride can be more corrosive than sodium chloride to automobile components in humid conditions, while sodium chloride is worse under immersion and arid conditions.[6] This is a single laboratory study of calcium nitrate, so a road or airport authority would need its own corrosion and concrete testing before use. Airfield chemicals are also tested for carbon-brake oxidation and cadmium-plate corrosion under SAE AMS 1431 and 1435.[7]

What is the environmental problem with nitrate deicers?

Chlorides do not degrade; once in water they persist and can mobilise metals and alter soil structure and ecosystems.[13] EPA freshwater criteria for chloride are 230 mg/L chronic and 860 mg/L acute.[19] Calcium nitrate avoids chloride, which is its attraction. It substitutes a different load. Extension guidance lists nitrogen salts such as urea and ammonium sulfate as rarely used because nitrogen runoff harms groundwater,[16] and a 1994 deicer patent described the inclusion of nitrates in a prior-art formulation as potentially damaging to the environment.[14] Nitrate has an enforceable U.S. drinking-water limit of 10 mg/L (as nitrogen).[18] EPA’s airport deicing rule specifically targets urea (through ammonia and oxygen demand), not nitrate,[10][12] but the same nitrogen-in-runoff logic applies near surface water and wells. The USGS has published work on the aquatic toxicity of airfield pavement deicer materials,[21] and any site using calcium nitrate should treat runoff discharge as a design issue.

Where does calcium nitrate honestly fit?

What about zeolite and calcium nitrate anti-slip deicers?

Some retailers sell a solid anti-slip agent made of zeolite containing calcium nitrate, described as chloride-free and used between 0 and −15 °C at 5–20 dkg/m2 (50–200 g/m2), with the manufacturer advising dosage trials.[22] These are manufacturer claims, not independent test data, and we cite the product only as an example that the combination exists commercially. Do not treat the rate as a specification.

How do aircraft and runway deicing differ from road deicing?

Aircraft are deiced with glycol fluids: Type I (deicing) and Type IV (thickened anti-icing), mostly propylene glycol with 1–3% additives,[11] classified under SAE specifications.[25] Pavements use solid or liquid chemicals meeting AMS 1431 or 1435, and chlorides are generally avoided on airfields because of aircraft corrosion risk.[7][23] Potassium acetate dominates U.S. pavement use, at 22,538 tons per year in EPA’s survey, followed by urea (4,127), propylene glycol fluids (3,883), sodium acetate (3,100) and sodium formate (1,117).[11] Glycols exert a very high oxygen demand when they degrade, which is the central regulatory concern for aircraft deicing runoff.[11]

What should a buyer specify if testing calcium nitrate as a deicer?

  1. Define the pavement type (concrete, asphalt, bridge deck, airfield) and the lowest temperature you must handle; compare against the eutectics above.[1]
  2. Ask the supplier for form (powder, granular, anhydrous or hydrated), moisture, calcium and nitrogen content, and insoluble residue, with a batch Certificate of Analysis. The research recommended anhydrous granular for runways,[2] so powder trials may behave differently.
  3. Run your own corrosion and concrete-scaling tests; do not rely on one published study.[2][4]
  4. Check local rules on nitrogen in stormwater and groundwater before use.[10][18]
  5. Use the lowest effective quantity; extension guidance advises using deicers sparingly to limit soil, water and concrete damage.[16]

When calcium nitrate is NOT the right choice

What HRSU supplies — and what it does not

HRSU Indore supplies fertilizer-grade calcium nitrate powder: 18.5–19% calcium, 15.5% minimum nitrogen, 100% water-soluble with 0% insoluble residue, in 25 kg and 50 kg bags, with a Certificate of Analysis per batch, bulk and export supply, and TDS and SDS on request. HRSU does not claim this grade is approved, tested or certified as a deicer, as an airfield product under SAE AMS 1431 or 1435, or for any road-authority specification, and does not claim it is the anhydrous granular form studied in the research. If you are evaluating calcium nitrate for deicing, request a sample and the TDS, state your pavement type and temperature range, and run your own corrosion and runoff checks before any field use.

Request a calcium nitrate sample and COA for your deicing trial

100% water-soluble · 0% insoluble residue · 25 kg & 50 kg bags · bulk/export available.

Buy online WhatsApp us

Frequently asked questions

Is calcium nitrate used as a deicer?

It is a niche deicer. Russian laboratory research studied it from 0 to −31 °C and reported no attack on metals, aircraft alloys or cement concrete, but it is not named in the Transport Canada runway ice-control circular and is far less used than salt, magnesium chloride or acetates.[2][7]

What are the main deicing agents?

Sodium chloride, calcium chloride, magnesium chloride, calcium magnesium acetate and potassium acetate for roads and pavements; urea and organic salts (sodium acetate, sodium formate) for airfield pavements; and propylene or ethylene glycol fluids for aircraft.[1][11][16]

Which deicer works at the lowest temperature?

By eutectic temperature, potassium acetate (−60 °C) and calcium chloride (−51 °C) lead, followed by magnesium chloride (−33 °C), CMA (−27.5 °C) and sodium chloride (−21 °C). Practical working limits are warmer.[1][17]

Is calcium nitrate better than rock salt for concrete?

A single laboratory study found calcium nitrate does not attack cement concrete,[2] whereas chloride deicers can damage concrete, with calcium and magnesium chloride forming harmful oxychloride phases at high concentration.[4] Independent field data are lacking, so test before adopting.

What is the environmental downside of calcium nitrate deicing?

It adds nitrate nitrogen to runoff. Extension guidance says nitrogen-based deicers are rarely used because of groundwater impact, and the EPA drinking-water limit for nitrate is 10 mg/L as nitrogen.[16][18]

What deicer is used on airport runways?

U.S. airports mostly use potassium acetate (about 80% of airfield deicing chemical use in EPA’s survey), with sodium acetate, sodium formate and some urea; large airports must use non-urea deicers or meet an ammonia limit.[10][11][12]

Is there a zeolite and calcium nitrate deicer?

Yes. Retailers sell a zeolite-based anti-slip product containing calcium nitrate, rated by the vendor for 0 to −15 °C; these are manufacturer claims, not independent test results.[22]

Can I use HRSU calcium nitrate as a deicer?

HRSU supplies fertilizer-grade powder with batch COAs and makes no deicer approval claim. Request a sample and TDS, state your use case, and validate corrosion, performance and runoff yourself.

Related guides

References

  1. Manual of Practice for an Effective Anti-icing Program (FHWA-RD-95-202), chapter on anti-icing chemicals and eutectics — U.S. Federal Highway Administration. Government
  2. New Deicing Calcium Nitrate-Based Agent (Danilov et al.), Theoretical Foundations of Chemical Engineering 53(5), 832-836, 2019, DOI 10.1134/S0040579519050063 — Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences / Springer. Peer-reviewed
  3. Deicers based on magnesium and calcium nitrates — Theoretical Foundations of Chemical Engineering (journal abstract). Peer-reviewed
  4. Durability of concretes exposed to high concentrations of CaCl2 and MgCl2 (Hosseinzadeh, Montanari, Suraneni et al.), Materials and Structures 55, 2022 — PubMed Central, U.S. National Library of Medicine. Peer-reviewed
  5. Chemical Interactions of Deicing Salts with Concrete Pastes Containing Slag Cement (Torabi et al.), Materials 18, 2025 — MDPI / PubMed Central. Peer-reviewed
  6. Corrosion Effects of Magnesium Chloride and Sodium Chloride on Automobile Components (Xi and Xie, 2002) — Colorado DOT study, Transportation Research Board TRID. Government research record
  7. Advisory Circular AC 302-014: Runway Ice Control Chemicals — Transport Canada, Government of Canada. Government regulator
  8. Engineering Brief 108: Ground Deicing / Anti-Icing Products — U.S. Federal Aviation Administration. Government regulator
  9. Advisory Circular 150/5200-30A: Airport Winter Safety and Operations (1991) — U.S. Federal Aviation Administration. Government regulator
  10. Effluent Limitations Guidelines and New Source Performance Standards for the Airport Deicing Category, 77 FR 29168 (2012) — U.S. Federal Register / EPA. Government regulation
  11. Environmental Impact and Benefit Assessment for the Final Effluent Limitation Guidelines and Standards for the Airport Deicing Category (April 2012) — U.S. Environmental Protection Agency. Government regulator
  12. Effluent Guidelines for Airport Deicing Discharges, Fact Sheet EPA-821-F-12-002 (April 2012) — U.S. Environmental Protection Agency. Government regulator
  13. Assessment of deicing salt storage and distribution as a salinization point source: influence of permitting standards on water quality (Tharp and Allen), Environmental Systems Research, 2020 — Springer. Peer-reviewed
  14. US 5,350,533: Pavement deicer compositions (General Atomics, 1994) — U.S. Patent and Trademark Office, via Google Patents. Patent
  15. Alternate Highway Deicing Chemicals, Executive Summary (Dunn and Schenk, FHWA-RD-79-109, 1980) — U.S. Federal Highway Administration, via ROSA P (U.S. DOT). Government
  16. Choosing the Best De-icers: Balancing Safety, Cost, and Environmental Impact — Utah State University Extension (Juab County). University extension
  17. Technical Brief: Alternatives to Salt, what else melts snow and ice? — Lake Simcoe Region Conservation Authority (Ontario public agency). Public agency
  18. Nitrate/Nitrite Toxicity: What are U.S. standards and regulations for nitrates and nitrites exposure? — ATSDR / CDC (archive). Government
  19. National Recommended Water Quality Criteria: Aquatic Life Criteria Table (chloride) — U.S. Environmental Protection Agency. Government regulator
  20. NCHRP Report 577: Guidelines for the Selection of Snow and Ice Control Materials to Mitigate Environmental Impacts (2007) — National Cooperative Highway Research Program, National Academies Press. Research report
  21. Aquatic toxicity of airfield pavement deicer materials and implications for airport runoff — U.S. Geological Survey. Government
  22. ZeoKal de-icer 10 kg (zeolite containing calcium nitrate), product page — Gazdabolt (retailer); example product only. Retailer
  23. Deicing (road and runway de-icing chemicals) — Wikipedia. Encyclopedia
  24. Calcium nitrate — Wikipedia. Encyclopedia
  25. Aircraft deicing fluid — Wikipedia. Encyclopedia
Reviewed by Sujay Shrivastava - Digital Transformation Consultant, HRSU Indore Pvt. Ltd. HRSU Indore manufactures and exports water-soluble calcium nitrate to 30+ countries.