- Half-life: 5,730 years
- Emissions: Beta particles with a maximum energy of 156 keV and an average energy of 49 keV.
- Maximum Range: 22 cm in air; 0.027 cm in tissue
- Fraction transmitted through the dead layer of the skin: 0.11
Dose Rate and Shielding
- Dose rate to the skin at 10 cm: 600 mrad/hour/mCi (for an unshielded point source)
- Dose rate to epidermal basal cells from skin contamination of 1 mCi/cm2: 1400 mrad/hour
- Shielding: None needed, when used in millicurie quantities under normal laboratory conditions.
- Annual Limit on Intake (ALI): 2 millicuries via ingestion. The ingestion of one ALI will produce a dose of 5 rem.
Wipe surveys using liquid scintillation counting is the preferred method for detecting C-14. Most G-M detectors are not likely to detect the presence of C-14 in amounts less than about 100,000 dpm (0.05 µCi).
Low-level C-14 contamination cannot be easily detected with a G-M meter, and special precautions are needed to keep the work environment clean. The regular use of wipe testing, using a liquid scintillation counter, is the only way to insure that your work space does not contain low-level removable contamination.
- Solid Wastes/Liquid Scintillation Wastes: through the Off-Site Radioactive Waste Disposal Program
- Liquid Wastes: through the Sewer Disposal Program. The laboratory disposal limit for C-14 is 3 mCi per month.