If the Special sample yields nonconforming results, UL institutes a production hold(i.e. product bearing the UL Mark may not be shipped from the manufacturer) and requires the Applicant to submit two "Hold Lot" samples within 30 days, as well as a written root cause analysis / corrective action plan, in order to resolve the nonconformance. The two Hold Lot samples are required to come from two separate production lots that incorporate the Applicant's corrective actions;
If UL and the Applicant are unable to resolve the nonconformance through the testing of these Hold Lot samples, the product is required to undergo re-qualification through UL's New Work submittal process;