• • • SAFETY IN ENGINEERING • • •
Out with the old, in with the new W
ith the UK’s withdrawal from the European Union, a number of regulations are changing. Among these is the legal requirements for declaring that certain classes of equipment or devices conform to relevant standards.
Under the EU regime, manufacturers and users of industrial devices will have become accustomed to the CE marking carried by such products. For example, for equipment intended for use in explosive atmospheres, the CE mark denotes that the eq1uipment meets the requirements of the ATEX Directive 2014/34/EU. Also known as ATEX 100, this Directive gives the safety requirements to be fulfilled by all equipment, both electrical and non-electrical, installed anywhere in hazardous areas within the EU.
This Directive was taken into UK law by the Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations 2016.
As UK law diverges from EU law, the CE mark is in the process of being replaced with the UKCA (UK Conformity Assessed) marking.
Government sets UKCA deadlines
The government timetable states that: ‘from 11pm on December 31, 2024, equipment and protective systems intended for the GB market should be conformity assessed by a UK approved body and should be UKCA marked, not CE marked.’ Only UKCA Issued ‘EX’ Certificates will be accepted in the UK for products that previously required ATEX Notified Body Certification. Until December 31, 2027, the UKCA marking can be affixed to a label on the product, or a document accompanying the product, rather than on the product itself.
The ‘GB market’ refers to England, Wales and Scotland. Slightly different rules apply to Northern Ireland. The UKNI marking is a new marking applied in addition to the CE marking. It applies when products that require third-party conformity assessment have been tested against EU requirements by a UK body - products lawfully marked with the UKNI marking can also be placed on the GB market if they are also qualifying Northern Ireland goods. This means that qualifying Northern Ireland goods that comply with the legislation as it applies in Northern Ireland, including affixing the CE marking, may be placed on the GB market after 11pm on December 31, 2024.
There are also slightly different arrangements for Approved Bodies, independent assessors who confirm that products meet the relevant legislation. Existing UK notified bodies have been granted new UK ‘approved body’ status.
30 ELECTRICAL ENGINEERING • MAY 2023
These approved bodies are UK based conformity assessment bodies that are authorised to carry out the procedures for conformity assessment and certification for the GB market, as set out in the 2016 Regulations.
Zones remain the same Although the mark proving conformity has changed, fortunately the underlying principles of the Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations 2016 have not been amended. The Regulations cover any electrical or mechanical product that contains or constitutes a potential ignition source, and which also requires a special design or installation procedure to prevent starting an explosion. Regulated equipment includes control and communication devices and monitoring and detection equipment. Also covered are safety or control devices installed outside hazardous areas that are designed to have an explosion protection function, such as pressure-relief panels and fast- acting shutoff valves. In conformity with the ATEX regulations, equipment is designated by the type of potentially explosive atmosphere in which the equipment may be used – Group 1 for underground mines and Group 2 for surface industries.
As the UK introduces new conformity markings – UKCA – to replace the CE mark, David Bowers of ABB Measurement & Analytics looks at the new regulations and how explosion proof devices support a wider assessment of safety risk
In Group 2 the regulations also define categories of equipment, specified by their protection characteristics. The hazardous location zones they can be used in are also defined – zones 0, 1 and 2 for gases, vapours and mists and zones 20, 21 and 22 for dusts. A table showing the zones and the category of equipment that can be used in them is shown in figure 1.
A complete safety system Although important, a device’s suitability for use in the various defined zones is only part of the safety equation. They also need to support a defined level of process and functional safety appropriate for the process or installation – it may mean that to achieve a defined level of safety integrity and safety functionality, the devices need a level of redundancy and a self-diagnostic capability far exceeding that required of non- critical systems.
Ultimately it is the prevention of accidents that is the greatest priority. The imperative to protect personnel and by extension the local community ensures the case for excellence across all safety systems. If in doubt, the expertise of product managers and value providers trained to advise can help businesses navigate the updated regulations.
Category Degree of Safety Design Requirement 1
Very high level of safety
Two independent
means of protection or safe with two separate faults
2 High level of safety Safe with frequently occurring disturbances or with one operating fault
3
Normal level of safety
Safe in normal operation Application Where explosive
atmospheres are present Zone 0 continuously or for lengthy periods
Where explosive
atmospheres are likely to occur
Where explosive
atmospheres are likely to Zone 2 occur infrequently and be Zone 22 of short duration
electricalengineeringmagazine.co.uk
Zone 1 Zone 21
Zone 20
Expected Zone of Use
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