Proficiency Testing Programs

Proficiency Testing (PT) samples are quality assurance samples analyzed by testing laboratories as a tool for evaluating its ability to perform analytical testing for specific methods, parameters, compounds, and elements. The analysis of matrix-specific PT samples play an important role in a laboratory quality management program.  PT samples are also used to obtain and maintain laboratory certifications, including NELAP, DoD ELAP, and various state programs.  PT samples are also known as Performance Evaluation (PE) and Performance Testing samples.

Merit Laboratories participates in numerous Proficiency Testing (PT) programs, routinely scoring high marks for quality.  A few of the PT programs in which we participate include Water Pollution (WP), Water Supply (WS), Air & Emissions (AE), NELAC Potable Water, NELAC Non-Potable Water and Hazardous Waste, and Phenova Soil and Hazardous Waste.  Over the last five years, we have averaged 98.2% for all PT programs. 

Specifically, Merit participates in the following PT programs:

• NELAC Non-Potable Water and Hazardous Waste (Semi-Annually)

• NELAC Potable Water (Drinking Water)  (Semi-Annually)

• DMR-QA NPDES (Wastewater) (Annually)

• Phenova Non-Potable Water (WP) (Semi-Annually)

• Phenova Potable Water (WS Drinking Water) (Semi-Annually)

• Phenova Air & Emissions (AE) (Annually)

• Phenova Soil/Hazardous Waste (Annually)

PT samples are prepared by approved PT sample providers and supplied to participating laboratories. The true value concentrations of PT samples are kept confidential by the PT providers, only shared once all laboratories analyzing samples as part of a PT study have submitted their analytical results to the PT provider. The PT providers then issue a performance report to each individual participating laboratory that evaluates performance for each analyte compared to defined acceptance ranges.