tritium (HTO) hazard

["Les Slaback, Health Physics" <SLABACK@micf.nist.gov>]

I'm sorry if I did not make my point clear.
Skin dose is not an issue.
Absorption through the skin resulting in a whole body internaldose is the
issue.
For our next shipment the D2O will have a tritium concentration of 1.3 Ci/L.
Even a short direct skin contact will result in a significant exposure, and
if that contact were extended (e.g., contact with wet clothing)the dose
could be >>1 rem.
The ALI=80 mCi (This is equivalent to an intake of 16 ml at this conc.)

The maximum range of the tritium betas is around 0.6 mg/cm2.
This is substantially less than the 7 mg/cm2 depth of interest for shallow
dose consideration (even if tunneling is a consideration).
Dose delivered during the absorption process will be negligible compared to
the extended time the material is in the body.  If the tritium were in a
form that it could be 'stuck' in the epidermis this might be something to
think about.

SLABACK@MICF.NIST.GOV
   ...a little risk, like a bit of spice, adds flavor to life