A potential problem in tritium gas handling facilities is the contamination of skin following contact with metal surfaces previously exposed to tritium gas. Experimental work has demonstrated that the urine of humans exposed to such surfaces contained high concentrations of organically bound tritium (OBT) and tritiated water (HTO). Recent experiments with hairless rats demonstrated similar excretion patterns of OBT and HTO in urine; furthermore, they demonstrated that OBT is retained within the skin and can act as a source of tritium to the rest of the body. A dosimetric model based on human and animal observations is proposed and discussed.