Re: Indium-115

["Alan R. Marchand" <radarm@accessnv.com>]

For DOT regs to apply you must meet the definition of radioactive material
for DOT.
173.403
Definitions. For purposes of this subpart-

Class 7 (radioactive) material. See the definition of Radioactive material
in this section.

Radioactive material means any material having a specific activity greater
than 70 Bq per gram (0.002 microcurie per gram) (see definition of
``specific activity'').

Specific activity of a radionuclide means the activity of the radionuclide
per unit mass of that nuclide. The specific activity of a material in which
the radionuclide is essentially uniformly distributed is the activity per
unit mass of the material.

If the Material meets these definitions then you check the A1/A2 table. The
following section is for radionuclides not listed.

173.433
Requirements for determining A1 and A2 values for radionuclides and for the
listing of radionuclides on shipping papers and labels. 
173.433(a)
(a) Values of A1 and A2 for individual radionuclides that are the basis for
many activity limits elsewhere in this subchapter are given in the table in
§173.435. 
173.433(b)
(b) For individual radionuclides whose identities are known, but which are
not listed in the table in §173.435, the determination of the values of A1
and A2 requires approval from the Associate Administrator for Hazardous
Materials Safety except that the values of A1 and A2 in Table 10 may be
used without obtaining approval from Associate Administrator for Hazardous
Materials Safety. 
173.433(c)
(c) In calculating A1 and A2 values for a radionuclide not listed in the
table in §173.435, a single radioactive decay chain in which the
radionuclides are present in their naturally-occurring proportions, and in
which no daughter nuclide has a half life either longer than 10 days or
longer than that of the parent nuclide, will be considered as a single
radionuclide, and the activity to be taken into account and the A1 or A2
value to be applied will be those corresponding to the parent nuclide of
that chain. Otherwise, the parent and daughter nuclides will be considered
as a mixture of different nuclides. 
Section 173.433(d) provides equations to meet the previous sections.

Since the amount is below the DOT definition for radioactive class 7
material, it is not regulated by DOT.

Alan R. Marchand
Las Vegas, NV
radarm@accessnv.com

At 02:13 PM 1/23/98 -0600, you wrote:
>Dear Radsafers,
>
>I am posting a question for a collegue who is not a radsafe subscriber.
>Please respond directly to me at bioanlyt@miravant.com and I will
>forward your responses to him.
>
>Thanks.
>Hue Lu
>
>____________________________________________________________________
>
>I have a conondrum about isotope 115 of Indium.
>
>Here's the facts:
>1) According to the 77th edition of the CRC Handbook of Chemistry and
>Physics 115-In (not the "metastable" 115m-In) this isotope has a
>half-life of 4.4E14 years and  a natural abundance of 95.7%. The decay
>is negative beta at 0.495 MeV.
>2) According to Oak Ridge National Labs (who sell this isotope) this
>does not even qualify for DOT "radioactive" status because it's less
>than one nanocurie per gram. Cambridge isotope Labs does not consider
>this isotope radioactive either.
>3) The CRC says that 14-C has a half life of 5715 years and a negative
>beta emission energy of 0.1565 MeV.
>
>It seems as if Indium 115 has a higher emission than 14-C but why then
>is it not regulated?
>
>Am I misreading the CRC?
>
>If 115-Indium were used for autoradiography in medical research what
>level of sensitivity would be required to get an image?
>
>Thanks in advance!!
>
>Alex Hornkohl
>
>
>