In the ATEX process, there is a term you will encounter almost every time for Category 1 and Category 2 equipment: Module B. In this article we explain what Module B is, in which cases it is mandatory, and which other modules it is applied together with.
What Is Module B?
Module B is the stage referred to as "EU-Type Examination" in the EU's system of conformity assessment modules. In this module, a notified body, upon the manufacturer's application, examines a representative sample of the product (or its design file) and verifies that the product meets the relevant directive's essential health and safety requirements (EHSR). If the review is favorable, the notified body issues an "EU-Type Examination Certificate." This concept is not specific to ATEX alone; it is part of the notified body mechanism in general CE legislation — you can find the general framework in our article What Is a Notified Body?.
When Is Module B Mandatory Under ATEX?
| Category | Is Module B Mandatory? |
|---|---|
| Category 3 (G/D) | No - Module A (self-declaration) is sufficient |
| Category 2 (G/D) | Yes |
| Category 1 (G/D) and Group I | Yes |
We cover the category determination process in detail in our articles What Is ATEX? and How Is ATEX Certification Obtained?.
Is Module B Sufficient on Its Own?
No. Module B only certifies the conformity of the product's design, as a one-time assessment; however, it must also be continuously assured that every unit produced in mass production is manufactured according to this approved design. For this reason, Module B is applied together with one of the following production-stage modules:
- Module C2: Internal production control + supervised product tests (generally for Category 2).
- Module D: Production quality assurance system (an ISO 9001-like quality system audited by a notified body).
- Module E: Product quality assurance system.
- Module F: Product verification (testing each product, or through statistical sampling).
- Module G: Unit verification (full examination for a single product; generally for special/prototype equipment).
Which combination is chosen depends on the manufacturer's existing quality system, production volume and the product's risk level.
How Does the Module B Process Work?
- The manufacturer submits the technical file and a representative sample (or design file) to the notified body.
- The notified body examines the design's conformity with the relevant standards and essential requirements.
- Additional tests are requested if necessary, or tests are carried out in the notified body's own laboratory.
- If conformity is confirmed, an EU-Type Examination Certificate is issued.
- The manufacturer moves to the chosen production-stage module (D/E/F/G) and begins mass production.
Frequently Asked Questions
Is Module B sufficient on its own?
No, Module B only certifies the conformity of the design; a production-stage module must also be applied to demonstrate that mass production continues to conform to this design.
Does the Module B certificate have a validity period?
The EU-Type Examination Certificate is generally valid for a specific period and remains valid as long as there is no change to the product design; notified bodies may request periodic review.
Is Module B required for Category 3 equipment?
No, Category 3 equipment can be placed on the market via self-declaration under Module A; Module B is mandatory only for Category 1 and 2.
Conclusion
Module B is one of the most critical stages of the process, providing an independent verification layer for ATEX's high-risk equipment categories. Planning it together with the correct production-stage module guarantees both conformity and the predictability of the process.
For more information, see our ATEX consultancy service.
Get a Free Preliminary Assessment