Abstract: The present invention concerns heat-transfer fluid compositions, such as concentrated and ready-to-use heat-transfer fluid compositions, comprising a base fluid, a divalent metal cation and an organophosphorus acid or a salt thereof, wherein the compositions have an electrical conductivity at 25° C. of less than 500 ?S/cm, wherein the base fluid consists of water and alcohol, wherein the alcohol is present in an amount in the range of 10-99.5 wt. % by weight of the base fluid, and wherein the composition comprises more than 75 wt. % of the base fluid by total weight of the composition.

Abstract: The present invention concerns concentrated and ready-to use coolant compositions comprising a base fluid and N-vinylpyrrolidone polymer wherein the compositions have an electrical conductivity at 25° C. of less than 100 ?S/cm, wherein the base fluid consists of water and alcohol, wherein the alcohol is present in an amount in the range of 10-99.5 wt. % by weight of the base fluid, wherein the composition comprises more than 75 wt. % base fluid by total weight of the composition, and wherein the amount of inorganic compounds is less than 100 ppm by total weight of the composition.

Abstract: The present invention relates to heat-transfer fluids with low conductivity which comprise a base fluid and at least one aliphatic carboxamide and are useful for diverse applications, for example in fuel cells. it was found that aliphatic carboxamides significantly outperform aromatic carboxamides with regard to maintaining low conductivity upon aging at increased temperatures. Furthermore, it was surprisingly found that the compositions in accordance with the invention are capable of maintaining this low electrical conductivity upon aging at increased temperatures in the presence of aluminum substrates.