❄️ Defrosta – a Finnish solution for winter use of SCR systems

Winter conditions pose specific challenges for the SCR systems of heavy-duty equipment. Prolonged cold spells, large urea solution tanks, and outdoor vehicle storage can compromise system reliability and cause malfunctions, particularly in AdBlue systems. Defrosta has been developed to address precisely these challenges.

Finnish innovation for demanding conditions

Defrosta is a urea-based additive manufactured in Ylöjärvi, Finland, based on Kemira's patent and development work. The product is produced by Kemion (Bang & Bonsomer).

The aim of the product is to provide a reliable and robust solution for urea-based SCR systems, especially in conditions where the use of conventional AdBlue has proven challenging.

AdBlue and winter—a well-known issue in the field

AdBlue freezes at approximately –11°C (12.2°F). During harsh and prolonged cold spells, this can result in:

• freezing and crystallization
• SCR system malfunctions
• starting and operating limitations
• additional maintenance and repair costs

In extreme scenarios, such as emergency service vehicles, SCR systems have occasionally had to be bypassed to ensure vehicle operability. For professional drivers, this problem has been technically and financially significant for years.

How does Defrosta help?

Defrosta is designed for use in urea-based SCR systems to enhance their resistance to freezing and operational reliability. The product is specifically developed for:

• long and severe frost periods
• large tank capacities
• fleets operating continuously outdoors
  
  Defrosta helps ensure SCR system functionality even at temperatures down to about –30°C (–22°F) and reduces crystal formation issues typical of AdBlue, which can cause malfunctions and equipment damage.

ℹ️ Important note on using Defrosta in SCR systems
Defrosta is a urea-based additive, not an AdBlue replacement.
AdBlue is always the base fluid in the SCR system, and Defrosta is to be added as an additive to enhance system reliability in cold environments.

Defrosta is not an ISO 22241-compliant AdBlue product and is not intended to be used exclusively in SCR systems. The manufacturer has not specified an official minimum amount of AdBlue to be used with Defrosta, nor should any mixing ratios be interpreted as usage or replacement recommendations.

The product's technical parameters and information regarding freezing behavior are intended to assist with winter operational planning, not as instructions for SCR system usage.

Testing and professional use

Defrosta is intended for professional use and is currently being tested in various vehicle types during the current winter season. The goal of testing is to ensure the product's effectiveness under diverse operating conditions and in different SCR systems.

⚠️ Note regarding manufacturer warranties
It is important to note that vehicle manufacturers' warranties may be voided if AdBlue is replaced by Defrosta or if the system uses fluids not approved by the manufacturer. Defrosta does not yet have official vehicle manufacturer approval.

For this reason, Defrosta is primarily suitable for professional fleets in applications where operational reliability under demanding conditions is critical, and usage decisions are made based on comprehensive consideration.

⚠️ Sensor notice
In some vehicles, the AdBlue tank is equipped with a urea concentration sensor. In such vehicles, the use of Defrosta may result in instrument cluster error messages, since the mixture's composition differs from standardized AdBlue.

Summary 

Defrosta is a domestic, professionally-designed additive developed to improve the reliability of SCR systems in demanding winter conditions. It offers an alternative solution in situations where traditional AdBlue is not sufficient to ensure uninterrupted operation.

👉 Learn more about the Defrosta product and its technical specifications in our online store.