UKCA and UKEX certification for engine starters

UKEX certification is the Great Britain route to proving that equipment is safe to use in a potentially explosive atmosphere, assessed by a UK Approved Body and shown by the UKCA marking. It is the domestic counterpart to ATEX certification in the European Union, and since October 2024 it sits alongside CE marking rather than replacing it.

If you are specifying an engine starter for a hazardous area on a British site, that last point is the one that matters most, and it is the one most often reported wrongly. Great Britain now has its own regime, but it did not close the door on the European one.

This article sets out which marking applies in which market, what certification means for a non-electric engine starter specifically, and what to ask a supplier before you commit to a model. If you are weighing the European scheme against the international one, we cover the difference between ATEX and IECEx separately.

What UKEX certification actually is

UKEX is the name used for certification against the Great Britain regulations covering equipment for explosive atmospheres. The legal instrument is the Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations 2016, which was carried across from the European ATEX Directive and then became domestic law in its own right.

The practical differences from ATEX are administrative rather than technical:

• The conformity assessment is carried out by a UK Approved Body rather than an EU Notified Body.
• The certificate is issued against the GB regulations, and the product carries the UKCA marking.
• The essential health and safety requirements themselves are, at the time of writing, materially the same as ATEX. A product engineered to satisfy one is normally engineered to satisfy the other.

The word UKEX does not appear in the regulations. It is industry shorthand, in the same way that ATEX is shorthand for the directive rather than a mark in itself.

Which marking applies where

Why CE marking is still accepted in Great Britain

Recognition of CE marking in Great Britain was originally time limited, with a series of deadlines that were extended more than once. In August 2023 the government announced that recognition would continue indefinitely across a list of product regulations, and equipment for potentially explosive atmospheres was named on that list. This was given legal effect by the Product Safety and Metrology etc. (Amendment) Regulations 2024, in force from 1 October 2024.

What this means in practice is that the question to ask a supplier is not "is it UKEX certified". It is whether the equipment is certified at all, by whom, to what equipment group and category, and whether that certificate covers the market you are installing in.

What certification means for a non-electric starter

Hazardous area compliance for engine starting is usually framed as a question about the starter's own certification. It starts one step earlier than that, with what the starter does and does not bring into the area.

An electric starter motor is an electrical device drawing very high current, with brushes and a solenoid, in an area where the whole point of the zoning exercise is to control ignition sources. Air, hydraulic and spring starters crank the engine from stored energy instead, so there is no electrical supply, no arcing contact and no battery bank at the engine. The ignition source is removed rather than enclosed and certified.

That does not make a non-electric starter automatically suitable. Non-electrical equipment still has to be assessed, because mechanical friction and impact can ignite a flammable atmosphere on their own. The current design standards for non-electrical equipment are EN ISO 80079-36 and EN ISO 80079-37, which cover the basic method and the specific protection types.

Why pre-engaged is specified for classified zones

This is where the specification detail earns its place. A pre-engaged starter brings the pinion into full mesh with the ring gear before any drive is applied, so the teeth are already in contact when torque arrives and engagement happens at rest rather than at speed.

In a classified zone that controlled engagement is what matters, and it is why the pre-engaged design is the one to ask about when a starter is going into one. Both engagement types have their place across a starter range, so the question is which one the zone calls for rather than which is better overall.

How this applies to the Powerstart range

Powerstart manufactures three non-electric starting technologies, and hazardous area work is served by the air and hydraulic ranges.

• Jetstream air turbine (pneumatic) starters. Operate on 3 to 30 bar. The Jetstream 4 suits engines up to around 15 litres and the Jetstream 5 up to around 80 litres. Available in inertia or pre-engaged. See the pneumatic starter motor range.
• M-Series hydraulic starters. Torque from roughly 30 to 216 Nm, cranking from stored accumulator pressure, typically around 200 to 210 bar, with a hand pump to recharge the system when no power is available. See the hydraulic starter range.

Spring starters suit smaller diesels, roughly 0.5 to 14 litres, and are specified on the basis of engine size and the absence of any stored air or hydraulic supply rather than on hazardous area grounds.

Certified options across the air and hydraulic ranges are set out on our ATEX starting systems page. If you need the certificate itself, the equipment group and category, or the marking as it appears on the nameplate for a particular model, ask us and we will send the documentation for the unit you are specifying.

What to ask before you specify

A short list to take to any supplier, including this one:

1. Which market is the equipment being installed in? Answer this first, because it determines which certificate you need rather than which one is nicest to have.
2. What is the zone classification? Equipment category follows from the zone, not the other way round.
3. Is it gas, vapour or dust? The designations differ and a certificate for one does not cover the other.
4. What is the temperature class required? This is driven by the ignition temperature of the substance present.
5. Can the supplier produce the certificate itself, not just a statement that the product is certified? Ask for the document.
6. Which engagement type suits the zone, inertia or pre-engaged?
7. If the project spans several countries, is IECEx being asked for alongside the regional marking?

Where to go next

If you are working out which certification scheme your project needs, ATEX and IECEx compared covers the two schemes side by side. For the equipment itself, the ATEX starting systems page sets out the certified options, and our oil and gas engine starting page covers typical applications.

Frequently asked questions

Melissa Payne BA, MA

Operations Director, Powerstart

Melissa Payne is Operations Director at Powerstart, the UK manufacturer of pneumatic, hydraulic and spring engine starters. She has spent over a decade in the non-electric engine starting industry, progressing from marketing and sales leadership to General Manager and now Operations Director, and has served on the marketing committee of AMPS, the Association of Manufacturers of Power Systems. She works across every part of the business, from customer support through to the quality and delivery of Powerstart's starting systems for oil and gas, marine, mining, power generation and fire pump applications.

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