Who should participate in the​ program?

Participation in the ELPAT Program is open to all laboratories but it is mandatory for laboratories seeking accreditation by one of the recognized accrediting organizations under EPA's National Lead Laboratory Accreditation Program (NLLAP). NOTE: NLLAP only covers paint, soil and dust wipes.

Must a laboratory analyze all analytes to participate?

An Environmental Lead accredited laboratory is required to analyze and submit results for those matrices that the laboratory is accredited for, so not all participants will analyze all samples. Non-accredited laboratories may participate in just the proficiency testing program (any matrices) in an effort to enhance their external quality control or prepare for accreditation.

What types of samples will be used in the ​program?

Matrices under the ELPAT Program include paint chips, soil, dust wipes, and air samples. After enrollment into the ELPAT Program, your laboratory will begin to receive sample kits on a quarterly basis. Four concentration levels will be shipped for each of four matrices: paint chips, soil, dust wipes, and air samples.


Number of Samples

Concentration Range
(general range)

Paint Chips*

4 samples

0.01% - 30%


4 samples

20 mg/kg - 20,000 mg/kg

Dust Wipes*

4 samples
1 blank

10 μg/wipe - 40,000 μg/wipe

Lead in Air*

4 samples

0.015 mg/m3 - 0.5 mg/m3

* AIHA Proficiency Analytical Testing Programs (PAT Programs), Falls Church, VA, is accredited by A2LA (Certificate Number 3300.01) for the programs indicated.

  • Paint chip samples are obtained from lead-based paints that have lead sources representative of the compounds and interferences encountered in field samples.
  • Soil samples are representative of environmental contamination resulting from lead-based paint, the industrial use or disposal of lead-based compounds, or airborne lead emissions.
  • Dust wipe samples are prepared using field-collected dust samples. Dust wipe sample sets include a blank. Notice: The wipe used in the ELPAT Program changed beginning in ELPAT Round 102. The new wipe, GhostWipeTM, is manufactured by Environmental Express, Charleston, SC, (800) 343-5319. Use of the GhostWipeTM or any other brand of dust wipe in the AIHA ELPAT Program does not constitute endorsement or recommendation for use by AIHA nor does it mean or imply that GhostWipeTM or any other brand are the only brands of dust wipes that can be used for the collection of lead dust.
  • Lead-in-Air samples are the same metals samples analyzed in the Industrial Hygiene Proficiency Analytical Testing (IHPAT) Program. Although there are two other metals on the filters, only lead is to be reported for the ELPAT Lead-in-Air Program. If you also participate in the IHPAT Program for metals, the metals on filters results must be reported for both programs. There will be no additional charge for the ELPAT (Air) PT samples for those laboratories concurrently enrolled in IHPAT (Metals).

When are the proficiency t​esting rounds held?

Four ELPAT (paint, soil and dust wipes) rounds are held each year, in February, May, August and November. Lead-in-Air (IHPAT Metals) rounds are held in January, April, July, and October. The samples are shipped out at the beginning of the month. Each laboratory has until the end of the month to complete sample analysis.

How are proficiency sam​ples sent?

Proficiency samples are shipped via the United States Postal Service. Upon receipt of the proficiency testing samples, it is the responsibility of the laboratory to inspect the shipment for any damage and to ensure that the correct samples were received. If samples are damaged, then the laboratory shall notify the PAT Programs within 24 hours of sample receipt to ensure timely replacement of samples for the laboratory to meet the deadline for submission of data. Laboratories requesting special shipping for replacement samples shall assume the cost of express carrier handling.

If the PT samples are not received by the laboratory in accordance with the predefined schedule, then it shall be the responsibility of the laboratory to contact the PAT Programs within one (1) week of the scheduled shipping date to notify us of failure to receive the PT samples. A laboratory that receives ELPAT samples but does not submit results or contact PAT Programs before the deadline will receive unacceptable results for the round.

Are special analy​tical methods required?

The ELPAT Program does not specify a particular analytical method to be used. Your laboratory must use the same procedure when analyzing similar types of samples in its normal operations. ELPAT samples should be rotated among all analysts performing similar analyses in your laboratory.

What happens after th​e results are submitted?

Your laboratory's ELPAT results will be evaluated using statistical procedures established by the National Institute for Occupational Safety and Heath (NIOSH). Organization reports will then be made available online for all participants.

What are the criteria used​ for rating my performance?

Performance ratings are based on accumulated results over four rounds (one year). The acceptable range is based on consensus values from reference laboratories. The acceptability of reported results is based on upper and lower performance limits.

How is proficiency determin​ed?

A participant's performance for each matrix is rated as proficient if either of the following criteria is met: (1) in the last two rounds, all samples are analyzed and the results are 100% acceptable; or (2) three fourths (75%) or more of the accumulated results over four rounds are acceptable.

What happens if my laborat​ory is non-proficient?

If your laboratory becomes non-proficient, the laboratory may choose to purchase the retest PT sample to attempt to regain a proficient status immediately. The PT sample retest results shall replace the original results. PT retest samples may also be used to expedite initial proficiency for a new program or when adding an analyte to an existing program. A retest sample order form is available on the PAT Programs website and is also available in the PAT Programs Fee Schedule.​

Does the PAT Programs offer QC samples?

PAT Programs offers samples from previous rounds for participants wishing to evaluate analytical procedures and quality control systems. Certificates of analysis are provided with the samples to permit evaluation of how well the participant performed. Kits consist of four concentration levels for each matrix, which include paint chips, soil, and dust wipes. Dust wipe samples include a blank.

Who prepares the proficiency testing samples?

ELPAT samples are developed and shipped by RTI International (RTI) on behalf of PAT Programs. ELPAT data analysis and distribution of reports are performed by PAT Programs.

Please contact PAT Programs at info.PATLLC@aiha.org for more information about the Environmental Lead Proficiency Analytical Testing Program.​

Last Updated: 03/29/2024 01:23PM