An Ex standards Q & A
03 September 2012
Q: Why can’t I have an EC-Type Examination Certificate?
A: This is a question that we are often asked, by manufacturers of Category 3 Equipment and Category 2 Non-Electrical Equipment. The answer is nothing to do with technical compliance (which for present purposes, I am assuming is achievable), but everything to do with the way the ATEX Directive is structured and the way that it is adopted as law. Put very simply, we Notified Bodies would be breaking the law if they issued an EC-Type Examination Certificate for these types of equipment.
EC-Type Examination is a very specific process defined in Annex III to the directive, and it is only permitted to be applied to Categories of Equipment for which it is mandated in the main text of the directive. That is all Category 1 Equipment, Category 2 Equipment which is either Electrical or an Internal Combustion Engine, and all independent Protective Systems. It can also be applied to integral protective systems if they are part of Category 1 or Category 2 (non-electrical) equipment.
Q: But my customer insists on a certificate.
A: This is a surprisingly common occurrence these days, particularly as intelligent customers become less keen to accept manufacturers’ Declarations of Conformity (DoC) at face value. There are two reasons for this scepticism:
1. Customers do value the assurance of third party involvement in the conformity assessment of a product;
2. The typical DoC contains little information of value to the customer and is sometimes misleading and full of errors.
The problem of errors is lessening, but is still prevalent among manufacturers who do not have involvement with Notified Bodies for other products. The content of a DoC is not on the list of the things that Notified Bodies are supposed to check according to Annexes IV and VII of the directive.
However, at one time, the DTI (now BIS) in the UK became so worried about the quality of DoCs that they asked the UK Notified Bodies to institute surveillance of the documents. Initially, we found that over half the documents we saw contained fundamental errors. I now judge this to be down to less than 10 per cent, but these are among the cadre of manufacturers that have had an input from a Notified Body. Manufacturers that do not require Notified Body involvement in ATEX compliance have not had that input.
Q: So how do I get a Certificate?
A: There are two options:
1. Ask for an ATEX Type Examination Certificate (i.e with the EC- missing);
2. For electrical equipment, take the IECEx route.
In 1999, the ATEX Notified Bodies Group (ExNB) recognised the problem of non-applicability of EC-Type Examination Certificates for Category 3 Equipment and came up with a format for an acceptable alternative to satisfy the market need. This was published in 2000 and you can download the document as ExNB/00/20/CS from the Commission website.
This form of certificate was deliberately chosen to give the same information as the EC-Type equivalent, hence the direct replication of the numbered paragraphs. The major difference is that the issuing body is acting in its capacity as a certification body, rather than as a Notified Body. Such a certificate is issued independently of any QA surveillance of the manufacturer, so the level of assurance in respect of subsequent product is limited.
The complete answer, giving full assurance that not just the tested sample but all subsequent production is in conformity, comes with adherence to the IECEx certification scheme. Here, all products are treated equally and are fully certified in an ISO Type 5 Certification System, where the certificate issued by the Certification Body is the top level document (and, in the case of IECEx, publically available on the IECEx web site).
All the manufacturer needs to do is to issue his DoC, using the IECEx Certificate and report as the technical file. Most bodies that are both Notified for ATEX and Accepted for IECEx will provide an Annex to the IECEx Report to cover the additional marking for ATEX.
This second, and in many ways preferable route, will soon be available for Non-Electrical Equipment as well. The standards are well advanced and are currently out as “Drafts for Public Comment” in the UK.
An international meeting is scheduled for November at which all the national comments will be considered by the IEC project teams and the final draft standard (FDIS) prepared for issue. Once this is prepared, it may be available for purchase as a pre-standard from the IEC web store (although as a dual branded ISO/IEC standard it may be available through ISO).
Manufacturers can get their applications for certification underway now, ready to be issued when the standard is formally published, possibly in the summer of 2013.
In his regular column for HazardEx, Ron Sinclair MBE keeps readers up to date on all aspects of ATEX and IECEx standards. He is General Manager of SGS Baseefa, Chairman of BSI Committee EXL/31, responsible for UK input to both European and International standards for Electrical Equipment for use in potentially explosive atmospheres, and Chairman of Cenelec TC31.