Patent ID: 8128872

Claim:
A freeze indicator comprising an indicator dispersion having an initial appearance, the indicator dispersion comprising: (a) an aqueous liquid medium having a melting point determined from the frozen state of the liquid medium; (b) solid indicator particles comprising an organic material and a softener to soften the indicator particles at the aqueous liquid medium melting point, wherein the softener is intimately admixed with the organic material and the indicator particles have a softness of at least about 20 dmm, as determined at 25° C. by Needle Penetration Test ASTM D1321, and are dispersed in the liquid medium; and (c) a particulate nucleating agent to inhibit supercooling of the liquid medium below the liquid medium melting point; wherein in the frozen state of the liquid medium the indicator particles are coalesced providing the indicator dispersion with a different appearance from the initial appearance and the coalescence and the different appearance are irreversible.