National foreword

This British Standard is the UK implementation of EN 12021:2014. It supersedes BS EN 12021:1999, which is withdrawn. It partially supersedes BS 8478:2011, as the test methods in Clause 5 specified in BS 8478:2011 have been retained.

This European standard specifies that ‘compressed gas for breathing shall not contain contaminants at a concentration which can cause toxic or harmful effects’ and that ‘all contaminants shall be kept to as low a level as possible’. In the opinion of the UK committee, contaminants that are not listed in this standard may also be present for various reasons; including leakage of ambient contaminants into the face mask. In some cases the effects of these contaminants could be additive or even considerably greater than the sum of their individual effects. In addition, an individual’s susceptibility to similar chemicals can vary significantly.

In regards to the UK implementation of this standard, the levels of contaminants specified in the tables should be used, independent of any National Workplace Exposure Limit (WEL). For those contaminants that are not listed in the tables in this standard, the level should not be greater than one tenth of the relevant time (8 h) weighted average Workplace Exposure Limit (WEL).

The UK National WEL for substances hazardous to health are published by the Health and Safety Executive and can be found in the publication, Workplace Exposure limits (EH40).

To ensure consistency in the application of this standard and in the analysis of the gases and any contaminants, a National Annex is included which includes the test methods previously specified in BS 8478.

The UK participation in its preparation was entrusted to Technical Committee PH/4/7, Underwater breathing apparatus.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

This publication has been prepared under a mandate given to the European Standards Organizations by the European Commission and the European Free Trade Association. It is intended to support requirements of the EU legislation detailed in the European Foreword. A European Annex, usually Annex ZA or ZZ, describes how this publication relates to that EU legislation.

For the Great Britain market (England, Scotland and Wales), if UK Government has designated this publication for conformity with UKCA marking (or similar) legislation, it may contain an additional National Annex. Where such a National Annex exists, it shows the correlation between this publication and the relevant UK legislation. If there is no National Annex of this kind, the relevant Annex ZA or ZZ in the body of the European text will indicate the relationship to UK regulation applicable in Great Britain. References to EU legislation may need to be read in accordance with the UK designation and the applicable UK law. Further information on designated standards can be found at www.bsigroup.com/standardsandregulation.

For the Northern Ireland market, UK law will continue to implement relevant EU law subject to periodic confirmation. Therefore Annex ZA/ZZ in the European text, and references to EU legislation, are still valid for this market.

UK Government is responsible for legislation. For information on legislation and policies relating to that legislation, consult the relevant pages of www.gov.uk.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2014.

This European Standard was approved by CEN on 6 February 2014.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.

Foreword

This document (EN 12021:2014) has been prepared by Technical Committee CEN/TC 79 “Respiratory protective devices”, the secretariat of which is held by DIN.

This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2014, and conflicting national standards shall be withdrawn at the latest by October 2014.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN 12021:1998.

Annex B provides details of significant technical changes between this European Standard and the previous edition.

This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s).

For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

1 Scope

This European Standard specifies requirements for the quality of compressed gas supplied for mixing or use in respiratory protective devices and hyper- and hypobaric operations. Account is taken of the use of compressed gases for normal atmospheric pressure as well as for hyper- and hypobaric pressures.

This European Standard does not apply to compressed gases used for medical purposes or for aerospace applications.

2 Normative references

3 Terms and definitions

4 Units

5 Reference conditions

6 Requirements

6.1 General

6.2 Breathing air

6.3 Mixing of gases

6.4 Odour

7 Sampling and testing

8 Designation

Bibliography

BS EN 12021:2014

Respiratory equipment. Compressed gases for breathing apparatus

Current

Published:

31 Mar 2026