The term Atex is derived from the French title of the original Atex directive Appareils destinés à être utilisés en ATmosphères EXplosives (Apparatus for use in explosive atmospheres)
The original Atex directive 94/9/EC dated 23rd of March 1994 became mandatory in July 2003 and all new equipment and protective systems for use in hazardous areas have been subject to it since. At that time any pre-Atex equipment already placed on the market could be continue to be used but should have been subject to ongoing risk assessments. The Directive was updated in line with the 'new legislative framework' and in April 2016. ATEX directive 2014/34/EU became mandatory in the EU
Atex is an EU legal framework for the use of equipment within the hazardous area not a product certification.
Therefore, by definition, Atex has no validity outside the EU unless other regulatory measures are in place.
Obviously the Atex documentation1 could be accepted outside of EU as it is in some non-EU countries and continued to be accepted in the UK until 31st December 20242
Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations 2016 (Statutory Instrument No 1107) originally implemented the Atex Directive in the UK (excluding Northern Ireland)3, this was then amended by The Product Safety and Metrology etc. (Amendment etc.) (EU Exit) Regulations 2019 (Statutory Instrument No 696. Schedule 25).
The changes implemented by IS 696 were explained in the November 2020 guidance notes published by the Office for Product Safety Standards which the following will use as its reference (unless otherwise detailed). Although, at the end of 2020 Brexit was complete. However, SI 696 did included an exception for Hazardous area equipment to allow Atex labelling in 2021 (only).
Common sense would dictate that the UK Declaration of Conformity would then just refer to the (allowed) Atex labelling/certification and then everything would align.
The requirements in 2022 for hazardous area equipment certification an labelling are clear. However, the legal acceptance of the EU Declaration of Conformity verses a UK DoC for compliance was unclear although it is generally accepted that the EU DoC is acceptable.
To the purchaser or end user, the only practical difference is liability if it goes wrong and then the judicial system would make a ruling.
However, this is now academic as the CE mark in place of the UKCA mark and therefore Atex certification has been now been deemed acceptable until the end of 2022.
Addendum: Announced in November 2002, it is intended the acceptance of Atex certification in the UK will be extended for another 2 years until the end of 2024.
Note the Product Safety and Metrology etc. (Amendment etc.) (EU Exit) Regulations 2022 variation which allows the use of UKCA marking on the basis of existing Atex certification has been withdrawn as the above announcement supercedes it.
Addendum 2 August 2023 - It has been announced that CE marking including ATEX will be accepted indefinately - Goodby UKCA.
See the Brexit page for more information
Notes
Acceptance outside of the EU usually is interpreted as referencing the Type Certificates in practice treating Atex certification as if it was Product Certification, which technically they are not. ↩
After many indecisions equipment with Atex Certification is now permanently accepted in the UK, although the Atex directive is not valid in the UK. ↩
In Northern Ireland The regulation for Hazardous area equipment (eyc.) is Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations (Northern Ireland) 2017 schedule 32 ↩