Carbon-14 (C-14) - doe-hdbk-1106-97

DOE-HDBK-1106-97

CARBON-14 (C-14)

Carbon-14 is a low-energy beta emitter (about 10 times more energetic than tritium). C-14 is not

easily detected with a hand-held survey instrument such as a thin-window G-M (the efficiency is

~ 10%). Monitoring is normally performed by taking a swipe of the area and counting the swipe

in a liquid scintillation counter.

Maximum energy: 0.156 MeV (the average energy is 0.052 MeV).

2. Maximum range in air: 9 inches (24 cm).

3. IAEA toxicity classification: Medium-low.

4. Physical half-life: 5,730 years.

Effective half-life (Teff): 12 days.

Critical organ: Whole body and the body fat.

7. Personnel monitoring: Bioassay - urinalysis and/or breath measurements (CO2), NOT

detected with a dosimeter (thermoluminescent dosimeter or film).

8. ALI:

2 mCi (7 x 107 Bq) -labeled organic compounds by inhalation or ingestion.

2 Ci (7 x 1010 Bq) CO by inhalation.

200 mCi (7 x 109 Bq) CO2 by inhalation.

9. Shielding: 3mm of plexiglass (if needed) - thicker plexiglass may be used for rigidity.

10. Special Considerations:

Detection of C-14 by radiation survey instruments requires special care due to the

low efficiency of detection.