Test Results and Subsequent Action

Our recommendation for action is based on the scientific community's requests. Many PI’s who measure natural abundances of 3H and 14C consider any value above our detection limit of 100 dpm/m2 evidence of contamination and will clean up the area even if the SWAB protocol does not recommend cleaning. The increasing sensitivity and precision of mass spectrometer measurement techniques allow researchers to accurately measure increasingly smaller magnitudes and differences in 3H and 14C. This requires that any possible contamination be kept to a minimum. Also, the bomb-produced signals for 3H and 14C are becoming increasing difficult to measure due to dilution and, in the case of 3H, significant radioactive decay.

<500 dpm/m2 for both 3H and 14C.

No action required.

 

500 to 10,000 dpm/m2 for both 3H and 14C.

The area must be cleaned before any natural abundance tracer work is conducted (does not apply to radiation vans).

>10,000 dpm/m2 for both 3H and 14C.

The area must be cleaned before any use (applies to radiation vans as well as ships and laboratories).

 

>100,000 and 50,000 dpm/m2 for 3H and 14C, respectively.

Indicates a possible health hazard, and Radiation Safety authorities from requesting institution will be immediately notified.