HPS N13.30

[Slaback@micf.nist.gov]

Having just received the mailing from HPS,
may I pose a question:
Table C.1 shows the MDC for C-14 and S-35 
to be the same (as would be reasonably expected).

But table 2 shows for a Minimum Testing Level (MTL)-
  C-14   2 kBq/L
  S-35   20 Bq/L

Why the difference?

10CFR20 ALI's are not that different -
  C-14 compounds  2E+3 uCi, CO 2E+6, CO2 2E+5
  S-35 vapor      1E+4 uCi, other forms 2E+3

The discussion for selecting an MTL is based on the
MDA (MDC), so why is such a lower number assigned for
S-35?

P.S.  The HPS is to be commended for the wide distribution
of this standard.  It has lots of good info.  In particular
I like the inclusion of the backup data to show the basis
for their various recommendations and the detailed statistics
discussion.

A little risk adds spice to life.
Lester.Slaback@NIST.gov