Determining Non Target Screening Thresholds for Recycled Polyolefins
Determining non target screening thresholds requires deriving analytical detection limits from toxicological thresholds divided by GC and LC response uncertainty factors.
Analytical Screening Threshold
Meaning
Concentration limits used in extraction testing of polymer materials establish the baseline below which compounds need not be identified. The analytical screening threshold defines the response level in chromatographic analysis where compounds must be quantified and reported.
Regulation Compliance
Standardization bodies set the levels of extraction testing to ensure toxicological safety. In the evaluation of medical grade plastics, the analytical screening threshold dictates the laboratory detection limits required to identify potentially harmful leachables. Higher thresholds lower the burden of testing but may overlook hazardous compounds.
Conversely, lower thresholds increase analytical costs by requiring highly sensitive mass spectrometry instrumentation.
Testing Limit
Chromatographic detection capabilities determine the feasibility of identifying trace impurities in processed plastics. Achieving a low analytical screening threshold requires rigorous calibration of gas or liquid chromatography equipment. Solid phase microextraction often concentrates the sample to meet these stringent limits.
If the threshold is set incorrectly, benign volatile organic compounds from polymer degradation may trigger unnecessary investigation.
Material Evaluation
Safety assessment files require verified raw data regarding compound migration from molded parts. During the formulation of custom masterbatches, the analytical screening threshold provides a definitive boundary for reporting non intentionally added substances. Resin suppliers rely on these boundaries to certify their materials for high purity applications.
If the compound concentrations remain below this specified level, the risk assessment proceeds without further chemical characterization, which significantly reduces the time and cost required to clear the formulation for clinical or consumer markets.