text: Carbon-14 has a long half-life of . Its maximum specific activity is . It is used in applications such as radiometric dating or drug tests. Carbon-14 labeling is common in drug development to do ADME (absorption, distribution, metabolism and excretion) studies in animal models and in human toxicology and clinical trials.  Since tritium exchange may occur in some radiolabeled compounds, this does not happen with carbon-14 and may thus be preferred.