thermolabile

Thermolabile is an adjective used to describe substances that are unstable or lose activity when exposed to heat. The term combines the Latin root thermo meaning heat with labile meaning easily changed or damaged. In chemistry, biochemistry, pharmacology, and related fields, thermolabile materials require careful temperature control to prevent degradation during storage, handling, or analysis.

Heating these substances can cause denaturation of macromolecules such as proteins, hydrolysis of sensitive chemical bonds, oxidation, or other forms of degradation that reduce potency or alter function. Thermolability is often discussed in contrast to thermostability, which describes resistance to heat-induced change. The degree of thermolability depends on temperature, duration of exposure, pH, presence of stabilizers, and the specific substance.

Storage and handling implications are significant. Thermolabile compounds are commonly stored under refrigeration (and sometimes freezing) and protected from temperature fluctuations. Reconstitution, if required, is usually performed on ice and used promptly. To minimize loss of activity, protocols may avoid repeated freeze–thaw cycles and employ cold-chain transport for field or clinical samples.

Common examples include certain vitamins (such as ascorbic acid) and other nutrients, various enzymes and proteins, and some pharmaceutical peptides or biologics. In food processing, heat treatment can inactivate thermolabile nutrients or enzymes, while in diagnostic laboratories, the integrity of thermolabile analytes depends on rapid processing and cold storage.

See also thermostability, heat-labile.