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Concentration Threshold (TSCA PBT)
Definition
Concentration thresholds establish minimum PBT chemical concentrations below which restrictions do not apply. Key thresholds: 2,4,6-TTBP at 0.3% by weight; PCTP at 1% by weight. The October 2024 revision introduced/clarified thresholds for PIP (3:1) and DecaBDE.
Source
40 CFR §§ 751.405, 751.407, 751.409, 751.411; EPA Final Rule (November 2024).
Practical Explanation (Compliance Context)
Concentration thresholds are compliance gatekeepers. If a product contains a PBT chemical below the threshold, prohibitions do not apply. Testing and supplier declarations should report against these specific thresholds.
Related Terms
Example
A rubber gasket contains PIP (3:1) at 0.05% by weight—below the applicable threshold. The gasket is not subject to distribution prohibitions. The manufacturer retains the test report.