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Who should participate in the IHP​AT Program?

If a laboratory analyzes samples taken from the workplace environment, then participation in the IHPAT Program can provide information to clients on laboratory performance. In addition, a laboratory must be a part of a proficiency testing program to participate in the AIHA's Industrial Hygiene Laboratory Accreditation Program.

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

The analytes covered under the IHPAT Program include: metals, silica, asbestos, solvents, and diffusive sampler badges. Based on what analyses are performed by the laboratory, sample kits contain up to five silica filters, five asbestos filters, five metals filters, and ten charcoal tubes (four samples, a blank and five tubes for determination of desorption efficiency). The metals filters contain three metals (lead, cadmium, n​ickel, manganese or chromium) which are rotated on the samples that are distributed each round. The charcoal tubes contain one, two or three organic solvents that are also rotated each round and include benzene, ethyl acetate, n-butyl acetate, methanol, 2-propanol, chloroform, 1,2-dichloroethane, 1-bromopropane, o-xylene, toluene, trichlorethylene, or tetrachlorethylene. The diffusive samplers contain three analytes (benzene, toluene and o-xylene).

Who should participate in t​he IHPAT diffusive sampler program?

The IHPAT diffusive sampler program is open to all interested laboratories. Laboratories that elect to enroll in the diffusive sampler program do so through the IHPAT program.

What types of samples ar​e used in the IHPAT diffusive sampler program?

The AIHA PAT Programs currently supplies diffusive sampler badges from these three manufacturers: 3M, SKC and Assay Technology. Laboratories that participate in the diffusive sampler program must choose the manufacturer type(s) that they want to use. Toulene (TOL), Benzene (BNZ), and o-Xylene (OXY) are the analytes currently being used. Sample kits shipped to laboratories consist of two monitors. A report form is provided for each monitor set and contains information on the manufacturer-supplied uptake rates. OSHA sampling rates for toluene and o-xylene are also provided for SKC samplers.

Concentrations will be reported in ppm using manufacturers' information on diffusion and concentration factors.

When are the IHPAT diffusive ​sampler rounds held?

The diffusive sampler rounds occur twice a year and coincide with the even rounds of the IHPAT program in January and July.

How does the IHPAT diff​usive sampler program work?

With the exception of the diffusive sampler rounds only occurring in January and July, the IHPAT diffusive sampler program is administered under the IHPAT program and is subject to all the IHPAT program procedures.

Are laboratories r​equired to analyze all IHPAT samples?

Participant laboratories may participate in this proficiency testing program in an effort to enhance their external quality control or prepare for accreditation.

How are proficiency samples s​ent?

Proficiency Samples are shipped via the United States Postal Service. Upon receipt of the PAT 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 AIHA 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 AIHA 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 IHPAT samples but does not submit results or contact AIHA PAT Programs by the deadline will receive a "Fail" for the round.

When is the next round o​f IHPAT and when is the deadline to sign up?

There are four IHPAT rounds in one calendar year. Once enrolled in the program, a laboratory will receive sample kits in January, April, July and October. Diffusive samplers are sent biannually in January and July.

The Industrial Hygiene PT Program​ Schedule*

​Enrollment Deadline 12/1​ 3/1​ 6/1​ 9/1​
​Round Open/Sample Ship 1/1​ 4/1​ 7/1​ 10/1​
​Results Due 2/1​ 5/1​ 8/1​ ​11/1​

* Please review the AIHA Proficiency Testing Program Schedule for further details.

Are special anal​ytical methods required?

The IHPAT program does not specify which particular analytical methods laboratories should use. A laboratory should use the same procedures when analyzing the IHPAT samples that it would use when analyzing similar types of samples in normal operations. This allows the effectiveness of the analytical methods used by the laboratory to be tested. Except in instances where analytical problems are found, IHPAT samples should be rotated among all analysts performing similar analyses in the laboratory, results from only one analyst should be reported.

What happens after the resul​ts are submitted?

After the close of the IHPAT round, the results are statistically evaluated, and a proficiency report is generated for each participating laboratory. Each laboratory will receive an e-mail notification once the results are available on the AIHA PAT Programs website. AIHA PAT Programs assists laboratories in making corrections and modifications prior to the next round of sampling by making retest samples available upon request. Results from the retest round replace the results for the failed round.

How is proficiency determined?

The IHPAT consists of four (4) rounds annually. The laboratory shall receive a pass/fail score for each analyte class (e.g., organics, metals, asbestos, silica), as applicable, for each PT round. The laboratory shall receive a passing score for the round if not more than twenty-five (25) percent of the reported results are outliers. The acceptability of reported results is based on upper and lower performance limits. For example, a laboratory participating in IHPAT (Metals) reports 12 results for each PT round. To pass the metals analyte class in each round, the laboratory shall have acceptable results for 9 of the 12 reported results. A laboratory is rated proficient for the associated FoT/Method if the laboratory has a passing score for the applicable PT analyte class in two (2) of the last three (3) consecutive PT rounds. A laboratory is rated non-proficient for the applicable FoT/Method if the laboratory has failing scores for the associated PT analyte class in two (2) of the last three (3) consecutive PT rounds.

What happens if my labora​tory is non-proficient?

If your laboratory becomes non-proficient in a specific FoT(s), based on PT sample performance, then 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 submitted by the laboratory and FoT proficiency shall be reevaluated based upon the PT retest 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 AIHA PAT Programs website and is also available in the PAT Programs Fee Schedule.

Does AIHA PAT Programs provide ​QC samples?

AIHA PAT Programs offers stock samples from previous rounds for laboratories wishing to evaluate analytical procedures and quality control systems. Certificates of analysis are provided with the samples to permit evaluation of how well the laboratory performed. Kits consist of four concentration levels for each analyte, which include metals, asbestos, silica, and organic solvents. Blanks are provided with each analyte. A stock sample order form is shipped to each laboratory along with their PT samples and is also available in the Fee Schedule.

Who prepares the proficiency testing samples?

IHPAT Samples are developed and shipped by SRI International on behalf of the AIHA PAT Programs. IHPAT Data analysis and distribution of reports are performed by the AIHA.

Please contact the AIHA PAT Programs at for more information about the Industrial Hygiene Proficiency Analytical Testing (IHPAT) program.​​​​​​​​​​​​​​​​​​​​

Updated: 10/30/2017 4:53 PM