Major Category
Physical/Radiation
Description
A hard and brittle metal; It is about twice as dense as lead; Some of the salts are highly colored; [Argonne]
Sources/Uses
There are 2 stable isotopes. About 63% is Ir-193 , and 37% is Ir-191. There are 15 major radioisotopes, and only 3 have a half-life greater than 1 month: Ir-192, Ir-192m, and Ir-194m. Natural iridium is obtained from nickel and platinum ores. [Argonne]
Comments
Most Important Radionuclide: Ir-192
Source: Usually produced in nuclear reactors by neutron absorption of Ir-191;
Half-Life: 74 days
Specific Activity: 9,200 Ci/g
Decay Mode: Beta, Electron capture;
GI Absorption: 1%
Lung Clearance Half-Time: Years for oxides and hydroxides; Weeks for halides, nitrates, and metallic iridium; Days for all other compounds;
Internal Toxicity: High
Annual Limit on Intake: 0.2 mCi
Tenth-Value Layer: 20 mm Pb
Gamma Ray Constant: 4.8 R/h @ 1 cm per mCi;
Radiation Energy (MeV): Beta 0.67 (49%); Gamma 0.308 (28%); Gamma 0.468 (46%);
Radiation Accidents: 27 accidents reported with 51 injuries and 10 deaths plus 1 report of "Meltings of Radioactive Materials";
[See Glossary for references.] See "Radiation, ionizing." See "Iridium."
Other Information
No other related information on this agent was found.