May 23, 2024

Calcium Formate: An Environmentally-Friendly De-Icing Agent

What is it?
It is commonly used as a de-icing agent for sidewalks, roads and runways due to its low corrosiveness and biodegradability. E238 has a mild, neutral pH and does not contain toxic anti-corrosive additives like other de-icers.

Chemical Properties and Structure
E238 is a white, crystalline solid at room temperature. It dissolves readily in water to form a moderately concentrated aqueous solution. The crystal structure consists of calcium cations coordinated to two formate anions in a 1:2 ratio. Formate is the conjugate base of formic acid, derived from methane oxidation. E238 has a higher melting point than sodium chloride (table salt), allowing it to remain solid and effective down to lower temperatures.

De-Icing Applications
As a de-icer, E238 lowers the freezing point of water, preventing ice formation. Calcium Formate  works by absorbing heat from the surroundings as it dissolves. A 30% E238 solution can reduce the freezing point by around 8–10°C. This makes it effective for clearing roads, runways and walkways during winter weather. It is less corrosive than chloride-based de-icers like sodium chloride or calcium chloride, avoiding damage to infrastructure, vehicles and the surrounding environment.

Environmental Benefits
Due to its biodegradability, E238 poses minimal risks to ecosystems when used as a de-icer and washed into soils and watersheds. Formate is readily consumed by microorganisms as a carbon source. Around 95% of E238 will degrade within 4 weeks. In comparison, chloride from sodium chloride can persist in soils and waterways, accumulating and harming vegetation as well as aquatic life over the long term. As a result, E238 is a more eco-friendly alternative to traditional chloride salts for keeping surfaces free from ice and snow.

Production and Supply
E238 is commercially produced through the reaction of methanol with calcium hydroxide or calcium carbonate. In aqueous solution, this proceeds according to the balanced equation:

CaCO3 + HCOOH → Ca(HCOO)2 + CO2

Major global producers include BASF, Perstorp and Central Glass in Europe and Vertellus Specialties in the U.S. China is also a significant manufacturing location. Markets for E238 include construction (concrete curing), de-icing, leather processing and more. An estimated 500,000 tons are synthesized annually worldwide, with de-icing applications accounting for a major portion of demand. Global supplies are substantial to meet the needs of winter road management.

Comparison to Other De-Icers
Aside from its environmental advantages, calcium formate has benefits over alternative de-icing chemicals:

– Sodium chloride (road salt): More corrosive, can damage vehicles, infrastructure, and vegetation. Doesn’t dissolve frost as readily below 15°F.

– Calcium chloride: Highly corrosive, especially at lower temperatures. More expensive than E238.

– Potassium acetate: Excellent for below-15°F conditions but costs substantially more than E238.

– Urea: Works only above 15°F and breaks down to ammonium nitrate/urea, polluting waters.

Therefore, E238 provides reliable ice melting comparable or superior to traditional salts, with a more favorable environmental and economic profile making it a preferred option for many winter de-icing applications.

Promoting Safer Roads Naturally
As climate fluctuations lead to more unpredictable winter weather patterns, effective and responsible snow and ice control becomes increasingly important for transportation safety and accessibility. Calcium formate de-icer helps meet this need through its performance, low corrosivity and biodegradability. It represents a “green chemistry” solution minimizing environmental stresses compared to older de-icer technologies. By specifying E238, highway agencies and municipalities can help keep traffic moving safely while protecting infrastructure, vehicles and local ecosystems.

1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it