Strategies for Producing Protective Concentrations
| Description of Leachable | Quantitation Strategy | Uncertainty Factor (UF)1 |
|---|---|---|
| Leachables with a confirmed ID | Use of compound-specific RRF | 1.183 |
| Leachables with an unconfirmed ID | Use of surrogate-matched RRF | 2 |
| Leachables with a proposed but unconfirmed ID | Use of RRFmedian | 2 (for GC/MS)2 |
| Unidentified leachable | Use of RRFmedian | 2 (for GC/MS)2 |
GC/MS, gas chromatography with mass spectrometric detection; ID, identification; LC/MS, liquid chromatography with mass spectrometric detection RRF, relative response factor; UF, uncertainty factor
1Reported Concentration = Calculated Concentration × UF.
↵2Given the much greater RRF variation and more poorly defined RRF distributions for LC/MS, a UF for LC/MS is not proposed, although a minimum value of 5 may be appropriate.
↵3Although use of such a small UF is consistent with the rigorous application of the concept of protection, use of such a small value may have limited practical value.