Sub-zero temperatures and frost are not uncommon in the winter, and these factors also affect coolants. The storage conditions of products need to be appropriate so that users can use coolants in top condition during the cold season. The reason for this is that the quality of a coolant can be impaired when it is exposed to frosty temperatures.

Why do frosty conditions affect the coolant?

Each coolant is a highly complex combination of specially formulated individual components and additives. Coolants should be protected against both frost and direct sunlight to guarantee their homogeneity, and thus guarantee top performance over the long term.

Our recommendation: Store coolants at temperatures between 5 and 40°C.

What happens when a coolant is exposed to temperatures below 5°C?

If this happens, the product may separate but it can be stirred at room temperature to restore its homogeneity. The longer it is exposed to temperatures below 5°C, the longer the reversible process will take. It can be assumed that the quality has not been reduced if all frozen components have been thawed and homogeneously distributed again in the product by means of stirring.

What should be done if the coolant has been stored below the recommended temperature for a longer period?

Check the condition of the product as follows:

  • Allow the coolant to completely warm to room temperature again
  • Homogenise (e.g. stir)
  • Take an average sample
  • Check the appearance and (for water-miscible coolants) emulsifiability

The coolant is completely viable if both the appearance/homogeneity and emulsifiability are fine.

Are you unsure about the viability of your coolant? Rhenus Lub’s experienced application specialists will be happy to assist you on +49(0)2161 5869-77.