# Carbon 14

Beta |
Beta Range |
Half Life |

0.04945MeV Mean energy | 24 cm in air | 5730 years |

0.15648MeV Max energy |

**In Use**

The following quantities will give a dose rate of 2 mSv/h without shielding.

- If handled at distances of 10 cm or more 100 MBq
- If handled at distances of less than 10 cm 1 MBq

Note that these quantities may be handled for a maximum of 15 minutes per day, five days a week, before the dose rate to the fingers is exceeded.

**Effective Dose Coefficients**

Inhalation coefficient |
Ingestion coefficient |
Skin dose coefficient |

5.8 x 10^{-10 }Sv.Bq^{-1} vapour |
5.8 x 10^{-10 }Sv.Bq^{-1} |
8.74 x 10^{-11} Gy.s^{-1} per Bq.cm^{-2} |

6.5 x 10^{-12 }Sv.Bq^{-1} dioxide |
||

8.0 x 10^{-13 }Sv.Bq^{-1} monoxide |

**Classification**

Classification is dependant on the form of the carbon-14.

If the total quantity of carbon-14 in the form of vapour in the laboratory is over 25 MBq*, it is necessary to classify the laboratory as a controlled area.

If the total quantity of carbon-14 in the laboratory is over 10MBq, it necessary to classify the laboratory as a supervised area.

*25MBq vapour if inhaled would give rise to an effective dose of 15mSv.