Frequently Asked Questions

Find answers to frequently asked questions about PJLA, international and national standards, the accreditation process and more.

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Why should I become accredited?

Accreditation provides the marketplace confidence that your laboratory has a well-established quality management system producing reliable and competent test and calibration results. Due to the increase of accreditation over the past few years, it is a necessity for laboratories to gain accreditation. This assists laboratories gain traceability of their test or calibration results throughout the world. It may also reduce the amount of supplier or regulatory assessments required and provide laboratories a competitive advantage in the marketplace.

What are PJLA’s credentials for being an accreditation body?

Just as our customers, Perry Johnson Laboratory Accreditation, Inc. (PJLA) is evaluated on a continuous basis by our oversight bodies APAC/ILAC. We are evaluated at least every 4 years, which validates our compliance to ISO/IEC 17011:2004 Conforming Assessment – General Requirements for Accreditation Bodies Accrediting Conformity Assessment Bodies as well as ILAC and APAC additional criteria. During this same visit PJLA is evaluated by regulatory, governmental bodies for any national programs we offer accreditation services for. Please visit the ILAC website at or APAC website at to view our credentials as a signatory to both MRAs.

How can I prepare for accreditation?

Initially laboratories should purchase a copy of the standard. This can be purchased under the International Organization for Standardization (ISO) website at A full system internal audit should be conducted and a full management review. This allows the laboratory to have a sufficient understanding of where any gaps are between their system and the requirements of the standard. Additionally, laboratories should ensure that all PJLA documents are being adhered to. These documents include the following:

  • PL-1 Proficiency Testing Requirements
  • PL-2 Traceability Requirements
  • PL-3 Measurement Uncertainty Requirements
  • PL-4 Calibration Scopes of Accreditation Requirements
  • WI-8 Testing Scopes of Accreditation Requirements

These can all be located on the PJLA Documents section of our website. Requirements in these documents will be assessed along with the requirements of the standard. Laboratories not meeting these additional requirements will be written a nonconformance. PJLA offers guidance to the standard on our website through the form of a working document checklist (LF-562k) also available for download from our PJLA Documents section of our website. Please visit our Accreditation Process page for an overview of our accreditation process and/or download our detailed Steps to ISO/IEC 17025 Accreditation booklet.

How long should I have an implemented system before I request my accreditation to by completed?

Assessors want to ensure that laboratories have the necessary procedures in place to generate data overtime. An example of this is proficiency testing as evidence of an internal measurement assurance program. Preferably assessors would like to assess several months of data. However, PJLA understands that laboratories with newly implemented quality management systems may not have access to a large amount of data. In this case, we make every effort to accommodate each laboratory and to assess data that is available at the time of the assessment along with related procedures.

What are the steps after I receive my accreditation?

PJLA requires all laboratories to conduct a surveillance visit at least 1 year after their accreditation visit is conducted. This visit is a less comprehensive assessment that focuses on the maintenance of the laboratory’s system. The assessor typically reviews the laboratory’s performance in regards to internal audits, management reviews, complaints, system changes and proficiency testing. Some of the laboratory’s scope will also be assessed during this time.

How long is a certificate valid?

Certificates are issued based on the date the accreditation review committee makes its decision with an expiration date of two years. For laboratories residing outside of the United States expiration date of five years is provided. Laboratories are expected to have a reaccreditation conducted at least 60 days prior to expiration to avoid a lapse in accreditation.