Proficiency Testing (PT) Samples

Overview

The OQA requires that certified laboratories successfully analyze PT Samples at prescribed intervals and that applied laboratories successfully analyze PT Samples to become certified. PT Samples contain known amounts of analytes that must be measured by a laboratory within defined acceptance ranges. The number of successful PT results required each year for a laboratory is dependent upon whether a laboratory is a NJ-ELCP or is a NJ-NELAP laboratory, and whether they are seeking certification for Safe Drinking Water (drinking water) or other programs (e.g., Non-Potable Water & Solid Hazardous Waste.).

The OQA previously contracted with Accredited PT Providers to supply Proficiency Test Samples to businesses participating in the NJ-ELCP and/or NJ-NELAP. As of October 2013, the State is no longer administering a PT Sample Contract and businesses will now be responsible for contacting approved PT Sample Providers to obtain their required PT Samples. Laboratories participating in the NJ-ELCP are required to acceptably analyze at least one PT Study annually for each parameter in which they hold certification. Laboratories that participate in the NJ-NELAP are required to acceptably analyze two PT Samples out of the most recent three PT Samples attempted within an 18-month period for each field of proficiency testing and those laboratories must participate in PT Studies every five to seven months. The PT parameters and matrices required for analysis are listed under the Required PTs section. Based upon these requirements the OQA has established a PT Study Schedule (see the PT Study Schedule Table) that laboratories must follow when obtaining PT Samples and submitting the results of these Studies to the OQA. The OQA will issue letters during the months noted in that Table that detail the requirements for obtaining and reporting PT Samples and the due date that final PT results shall be received by the OQA. Examples of those letters can be found within the Required PTs section.

DEP Approved Providers

All PTs must be purchased from a PT Provider that is accredited by a Proficiency Testing Provider Accreditor (PTPA) that meets the TNI requirements. Please see a list of DEP approved accredited PT providers.

PT Reporting

The reporting deadlines for each PT Study are specific to that Study based upon each PT Provider’s schedule. Please reference the reporting instructions sent with the PT Samples from the PT Provider for the reporting due date or the close date of the study. Note that if you are receiving PT samples from more than one PT Provider, the PT result reporting due date may be different for each PT Provider. Once the PT Samples are analyzed, laboratories shall submit the results directly to the PT Provider supplying the PT Samples. The PT Provider will evaluate the results and send the final results to both the laboratory and the OQA.

When reporting data to a PT Provider, the laboratory must submit the method in which it is listed as certified on its ACPL. If a laboratory reports a PT Sample result with a method other than that in which it holds certification, it will be evaluated as “Unacceptable” and will require the analysis of a make-up study.

If a laboratory is performing a PT study for initial certification, then it must make sure to choose the correct method when reporting the PT results. If an incorrect method is reported, the PT cannot be used for initial certification.

When reporting organic data, a result must be reported for all analytes for which the laboratory holds certification. For any organic analytes not detected in the PT Sample, the laboratory must report the result as being less than the laboratory’s Practical Quantitation Limit (PQL) or Reporting Limit (RL) in order to obtain acceptable recognition of analysis for the analyte.

Required PTs

Safe Drinking Water (SDW) PTs
For Safe Drinking Water (drinking water matrix) certification, a laboratory is required to analyze PT Samples for every method/technique in which it holds certification. For example, if a laboratory is certified in drinking water for aluminum by ICP and Furnace techniques, it is required to analyze and pass a PT Sample for aluminum by ICP, and analyze and pass a PT Sample for aluminum by Furnace, in order to retain certification for both techniques. Laboratories are permitted to analyze and report results for multiple methods/technologies, i.e. ICP and Furnace, for the same analyte, from a single PT Sample, but it must analyze the PT by all technologies in which it holds certification.

Below you will find the most recent letters which were sent to the laboratory community along with the list of parameters required to be analyzed for this program.

• SDW ELCP Announcement
• SDW TNI Announcement
• SDW Parameter Table

Solid/Chemical Materials PTs
The State of New Jersey requires laboratories certified in the Solid/Chemical Materials certification program to analyze PT Samples. Laboratories that currently have USEPA SW-846 certification for solid and chemical materials (SCM) preparatory methods for Organic and Inorganic analytes are required to analyze a solid PT Sample. If a laboratory does not hold SCM certification then the laboratory is required to analyze a Non-Potable Water (NPW) PT Sample.

Below you will find the most recent letters which were sent to the laboratory’s community along with the list of parameters required to be analyzed for this program.

• SCM ELCP Announcement
• SCM TNI Announcement
• SCM Parameter Table

Clean Air Program
The State of New Jersey requires laboratories certified in the Clean Air certification program (air/emissions matrix) to analyze PT Samples. All certified laboratories are required to pass one PT sample a year. ELCP laboratories that do not pass one sample a year will be suspended for that analyte. NELAP laboratories that do not pass one sample a year will not be eligible to report data to the State of New Jersey.

Below you will find the most recent letters which were sent to the laboratory’s community along with the list of parameters required to be analyzed for this program.

• AE ELCP Announcement
• AE TNI Announcement
• AE Parameter Table

Non-Potable Water (NPW) PTs and the Discharge Monitoring Report Quality Assurance (DMRQA) Study Program
On November 30, 2011, the U.S. Environmental Protection Agency (EPA) approved the Department’s request to withdraw from the National Pollutant Discharge Elimination System (NPDES) Discharge Monitoring Report – Quality Assurance (DMR-QA) Program. EPA granted approval of the withdrawal because the Department’s state-wide laboratory certification program is an adequate surrogate for the DMR-QA Program. Laboratories must assure that PTs are submitted for all parameters in which they hold a Non-Potable Water (NPW) Matrix.

Below you will find the most recent letters which were sent to the laboratory’s community along with the list of parameters required to be analyzed for this program.

• NPW ELCP Announcement
• NPW TNI Announcement
• NPW Parameter Table

PT Study Schedule Table

All letters out dates are subject to change and are tentative.

Make-up PT Studies

If a ELCP laboratory fails a routine first round PT study, it is given a chance to acceptably analyze a second study, or make-up study. Make up studies will occur approximately 6 months after the first round study giving laboratories a chance to make up for any failures in the first round PT Study. If the laboratory again fails the make-up study, then a minimum six-month suspension will occur for the analyte that is failed a second time. If the laboratory fails to submit results for the same parameter/method in the first round and make-up studies it will also be subject to a penalty assessment.

If a NELAP laboratory fails a routine PT study it can either do a supplemental PT no less than 15 days after the failed PT study or it can wait until the next scheduled study. In order to maintain the required NELAP PT schedule, all DEP primary NELAP laboratories are required to participate in each scheduled PT study for each analyte in which they hold accreditation.