Road maintenance finds eco-friendly de-icer but cost remains tenfold higher

A Finnish transport agency trial has identified formate—a compound derived from formic acid—as an effective and environmentally safer alternative to traditional road salt, though its significantly higher price limits widespread adoption, reports Yle.

Testing conducted last winter on major highways in southeastern Finland’s Luumäki municipality showed formate performed as well as or better than conventional salt, without raising groundwater chloride levels. The Finnish Transport Infrastructure Agency and the regional ELY Centre for Southeast Finland confirmed the substance fully replaced chloride-based de-icers during the trial period.

Environmental and operational benefits
Formate breaks down naturally in soil, avoiding the chloride buildup caused by salt, which can contaminate groundwater. Jarkko Pirinen, a road maintenance expert at the transport agency, noted the trial area saw no chloride leakage into aquifers, gradually reducing existing contamination. Finland’s existing equipment also proved capable of distributing formate without major modifications.

Yet the compound’s cost—roughly ten times that of salt—restricts its use to critical groundwater zones. Operators must weigh its benefits against expense, Pirinen said. While formate caused less corrosion to vehicles than salt, trial equipment showed accelerated wear when handling the substance.

International interest
Finland has previously used formate in limited road applications and more widely at airports. The Luumäki trial marked the first large-scale test of sodium formate, a solid variant, alongside the liquid potassium formate. Pirinen reported growing interest from Sweden, Norway, Austria, and Canada, where authorities see potential in the Finnish approach.

New regional maintenance contracts already incorporate formate requirements. Kari Halme of the Southeast Finland ELY Centre said upcoming agreements for Lappeenranta and Luumäki will mandate formate use on sensitive groundwater areas starting this autumn.