What Is an IECEx Testing Laboratory (ExTL)?

An IECEx Testing Laboratory (ExTL) is an independent laboratory accepted within the IECEx Certification System to evaluate explosion-protected equipment against the applicable IEC 60079 standards. Before hazardous area equipment can receive an IECEx Certificate of Conformity, it must undergo technical testing and engineering assessment conducted by an approved ExTL.

The ExTL plays a critical role in the IECEx certification process by verifying that a product's design, construction, and performance satisfy the technical requirements of the relevant explosion protection standards. The laboratory documents its findings in an IECEx Ex Test Report (ExTR), which becomes the primary technical evidence reviewed by an IECEx Certification Body (ExCB).

This article explains what an IECEx Testing Laboratory is, how it performs product evaluations, and why it is essential to the international certification of equipment intended for use in explosive atmospheres.

Quick Answer

What Is an IECEx Testing Laboratory (ExTL)?

An IECEx Testing Laboratory is an independent laboratory formally accepted within the IECEx System to conduct technical evaluations of equipment intended for use in explosive atmospheres. Its primary responsibility is to verify that equipment complies with the applicable IEC 60079 standards through laboratory testing, engineering assessment, and design review.

Unlike an IECEx Certification Body (ExCB), which makes the certification decision, an ExTL is responsible for generating the technical evidence that supports certification. This evidence is documented in the IECEx Ex Test Report (ExTR).

The laboratory operates under internationally recognized procedures to ensure that testing is performed consistently, objectively, and in accordance with the IECEx Operational Documents.

What Does an ExTL Do?

An IECEx Testing Laboratory evaluates whether explosion-protected equipment satisfies the technical requirements of the applicable explosion protection standards.

Its primary responsibilities include:

• Performing laboratory testing.
• Reviewing product construction.
• Evaluating explosion protection concepts.
• Assessing compliance with IEC 60079 standards.
• Preparing the Ex Test Report (ExTR).
• Supporting the IECEx certification process with technical evidence.

The laboratory does not issue IECEx Certificates of Conformity. Instead, it provides the technical information required by the IECEx Certification Body to make the final certification decision.

Who Can Become an IECEx Testing Laboratory?

Organizations wishing to operate as IECEx Testing Laboratories must be formally accepted within the IECEx Certification System. Acceptance requires demonstration of technical competence, suitable laboratory facilities, qualified personnel, calibrated testing equipment, and compliance with the applicable IECEx Operational Documents.

Each ExTL is assessed to ensure that it can perform testing consistently and objectively in accordance with internationally recognized certification procedures.

Only laboratories officially accepted by the IECEx System may prepare Ex Test Reports used to support IECEx certification.

Examples of IECEx Testing Laboratories

Many internationally recognized organizations operate approved IECEx Testing Laboratories.

Examples include:

• DEKRA Testing and Certification.
• UL Solutions.
• CSA Group.
• Baseefa.
• TÜV Rheinland.
• TÜV SÜD.
• Intertek.
• INERIS.
• LCIE Bureau Veritas.

These laboratories perform testing for a wide range of explosion-protected equipment, including electrical apparatus, industrial control devices, lighting fixtures, motors, junction boxes, cable glands, and other equipment intended for hazardous locations.

How Does an ExTL Support IECEx Certification?

An IECEx Testing Laboratory provides the technical foundation of the IECEx certification process. Before an IECEx Certification Body (ExCB) can issue an IECEx Certificate of Conformity, the ExTL must evaluate the equipment and demonstrate compliance with the applicable IEC 60079 standards.

A typical certification workflow includes:

1. The manufacturer submits equipment for IECEx certification.
2. The IECEx Testing Laboratory reviews the product design and applicable standards.
3. Laboratory testing and engineering evaluations are performed.
4. The ExTL prepares the IECEx Ex Test Report (ExTR).
5. The IECEx Certification Body (ExCB) reviews the ExTR together with the Quality Assessment Report (QAR).
6. If all certification requirements have been satisfied, the IECEx Certificate of Conformity is issued.

This process ensures that certification decisions are based on objective technical evidence rather than manufacturer declarations alone.

What Tests Are Performed by an ExTL?

The scope of testing depends on the equipment type and the applicable explosion protection technique. Each evaluation is performed according to the relevant IEC 60079 standards.

Typical laboratory assessments include:

• Construction review.
• Mechanical strength testing.
• Impact resistance testing.
• Ingress Protection (IP) testing.
• Temperature rise measurements.
• Dielectric strength testing.
• Creepage and clearance verification.
• Flame transmission testing for flameproof enclosures.
• Thermal endurance testing.
• Verification of equipment markings.

The results of these evaluations are documented within the Ex Test Report and become part of the certification record.

Which IEC Standards Does an ExTL Apply?

An IECEx Testing Laboratory evaluates equipment against the applicable standards within the IEC 60079 series. The specific standards depend on the explosion protection concept used by the equipment.

IEC Standard	Subject
IEC 60079-0	General Requirements
IEC 60079-1	Flameproof Enclosures (Ex db)
IEC 60079-7	Increased Safety (Ex eb)
IEC 60079-11	Intrinsic Safety (Ex i)
IEC 60079-18	Encapsulation (Ex mb)
IEC 60079-31	Protection by Enclosures for Dust (Ex tb)

Additional standards may also apply depending on the equipment design, intended application, and protection technique.

What Is the Difference Between an ExTL and an ExCB?

Although both organizations participate in the IECEx Certification System, their responsibilities are different.

IECEx Testing Laboratory (ExTL)	IECEx Certification Body (ExCB)
Performs laboratory testing.	Reviews certification evidence.
Evaluates technical compliance.	Evaluates the complete certification package.
Prepares the Ex Test Report (ExTR).	Reviews the ExTR and QAR.
Provides technical evidence.	Issues the IECEx Certificate of Conformity.

The ExTL and ExCB perform complementary functions that ensure IECEx certification is both technically rigorous and independently assessed.

Can an ExTL Also Be an ExCB?

Yes. Many internationally recognized organizations operate both an IECEx Testing Laboratory and an IECEx Certification Body.

Even when both functions exist within the same organization, they operate under defined procedures that maintain impartiality, technical competence, and compliance with the IECEx Operational Documents.

This structure allows efficient coordination between laboratory testing and certification while preserving the integrity of the IECEx Scheme.

Benefits of Using an Approved ExTL

Testing performed by an approved IECEx Testing Laboratory provides confidence that hazardous area equipment has been evaluated using internationally recognized procedures.

• Independent technical assessment.
• Testing in accordance with IEC 60079 standards.
• International recognition through the IECEx Scheme.
• Reliable engineering evidence supporting certification.
• Improved confidence for manufacturers, inspectors, and end users.
• Support for global acceptance of certified equipment.

By generating objective technical evidence, an ExTL helps ensure that explosion-protected equipment satisfies the performance and safety requirements expected for use in hazardous locations.

Common Misunderstandings About IECEx Testing Laboratories

An ExTL Issues IECEx Certificates

No. An IECEx Testing Laboratory (ExTL) performs laboratory testing and technical evaluations but does not issue IECEx Certificates of Conformity. Certification decisions are made by an IECEx Certification Body (ExCB), which reviews the Ex Test Report (ExTR) together with the supporting certification documentation.

An ExTL and an ExCB Are the Same Organization

Not necessarily. Although many internationally recognized organizations operate both an ExTL and an ExCB, the two functions are separate. The ExTL provides technical evidence through testing, while the ExCB evaluates that evidence and determines whether certification should be granted.

Testing Is Limited to Electrical Performance

No. IECEx laboratory evaluations include much more than electrical testing. Depending on the applicable protection concept, the ExTL may assess mechanical strength, enclosure integrity, ingress protection, temperature rise, flame transmission, creepage and clearance distances, equipment markings, and other construction requirements specified in the IEC 60079 series.

Only New Products Require ExTL Testing

Not always. Significant design changes, new product variants, changes to explosion protection concepts, or revisions to applicable IEC standards may require additional testing or technical evaluation before certification can be updated.

Frequently Asked Questions (FAQ)

What is an IECEx Testing Laboratory (ExTL)?

An IECEx Testing Laboratory (ExTL) is an approved laboratory within the IECEx Certification System that performs testing and technical evaluations of explosion-protected equipment in accordance with the applicable IEC 60079 standards.

Who prepares the Ex Test Report (ExTR)?

The Ex Test Report (ExTR) is prepared by an approved IECEx Testing Laboratory after completing the required testing, engineering evaluation, and construction assessment.

Can an ExTL issue an IECEx Certificate of Conformity?

No. Only an approved IECEx Certification Body (ExCB) is authorized to issue an IECEx Certificate of Conformity after reviewing the ExTR, the Quality Assessment Report (QAR), and the supporting certification documentation.

Can one organization operate both an ExTL and an ExCB?

Yes. Many internationally recognized organizations operate both an IECEx Testing Laboratory and an IECEx Certification Body, provided they maintain the competence, impartiality, and procedures required by the IECEx System.

How can I verify whether a laboratory is an approved ExTL?

The official IECEx website maintains a directory of approved IECEx Testing Laboratories participating in the IECEx Certified Equipment Scheme.

Conclusion

An IECEx Testing Laboratory (ExTL) is responsible for generating the technical evidence that supports IECEx certification. Through laboratory testing, engineering assessment, and evaluation against the applicable IEC 60079 standards, the ExTL prepares the Ex Test Report (ExTR), which serves as the foundation for certification decisions made by an IECEx Certification Body.

Understanding the role of an ExTL helps manufacturers, engineers, procurement specialists, inspectors, and facility operators appreciate the rigorous technical evaluation performed before explosion-protected equipment receives an IECEx Certificate of Conformity. Together, the ExTL, ExCB, ExTR, QAR, and Certificate of Conformity form the core elements of the IECEx Certified Equipment Scheme.

Technical Review

References

• IECEx Certified Equipment Scheme – Official IECEx Documentation.
• IECEx Basic Rules.
• IECEx Operational Documents (OD Series).
• IEC 60079 Series – Explosive Atmospheres.
• ISO/IEC 80079 Series.
• IECEx Online Certificate Database.