Radioisotope Information: HYDROGEN - 3 -- University of Wisconsin-Milwaukee Department of University Safety and Assurances: Radiation Safety Program

Radioisotope Information: HYDROGEN - 3
(³H)

Physical Half-life:	12.35 years
Radiations:	^-ß 18.6 keV
External Exposure:	Low energy ß, not external hazard, radiation badge not necessary.
Biological Data:	ALI	80 mCi
	Biological half-life	12 days
	Effective half-life	12 days
	Critical Organs	Body water
	Bioassay	Urinalysis
Shielding:	None is recommended. Range of ß in air is 0.65" and 0.00064" in lucite.
Monitoring & Efficiency:	LSC (Eff. ~40%) Cannot be detected with a GM meter.

Work with volatile forms of ³H, i.e., gas/tritiated water, in a fume hood.
Oxides of tritium can readily be absorbed through the skin. Wear 2 pairs of disposable gloves and other appropriate protective attire.
Tritiated DNA precursors, (e.g., tritiated thymidine), are potential internal hazards. In the body, some are incorporated into the cellular DNA with a biological half-life of one year instead of 12 days as in ³H₂O. Thus, inside the body, precursors may be more hazardous than ³H₂O.

For additional information contact the Radiation Safety Program at 229-4275.

Updated February 27, 2008 by SAK