Major Category
Physical/Radiation
Synonyms
See "Cobalt" CAS # 7440-48-4;
Description
Silver-white metal;
Sources/Uses
Cobalt-59 is the naturally occurring stable form of cobalt. Of the 9 major radioactive isotopes, only Co-57 and Co-60 have half-lives longer than 80 days. Cobalt-60 is formed by neutron activation in nuclear reactors and particle accelerators. [Argonne] Co-60 is used in medicine for instrument sterilization and radiation therapy for cancer; Used in industrial radiography and irradiation of food and grain; [Waltar, Appendix A-D]
Comments
Source: Neutron activation of stable Co-59;
Half-Life: 5.3 years
Effective Half-Life: 10 days
Specific Activity: 1,100 Ci/g
Decay Mode: Beta
GI Absorption: 5-30%
Lung Clearance Half-Time: >100 days for oxides, hydroxides, halides, and nitrates; 10-100 days for other compounds;
Critical Organ: Total body
Internal Toxicity: High
Annual Limit on Intake: 0.030 mCi
Tenth-Value Layer: 34.8 mm Pb
Gamma Ray Constant: 13.2 R/h @ 1 cm per mCi
Radiation Energy (MeV): Beta 0.313 (99.8%); Gamma 1.17 (99.8%); Gamma 1.33 (100%)
Radiation Accidents: 31 accidents reported with 211 injuries and 30 deaths plus C0-60 was involved in 16 incidents of "Melting of Radioactive Materials";
[See Glossary for references.] See "Radiation, ionizing."
BEI
Cobalt in urine = 15 ug/L; sample at end of shift at end of workweek;
Other Information
No other related information on this agent was found.