2020 marks the 25th anniversary for the source testing association

Where we came from?

In the mid-90s a meeting took place in Manchester with ten stack testing companies. The consensus was that there was a common concern within the industry with the quality of testing, equipment and more importantly, in health and safety.

Following the initial meeting, another meeting of over 100 stack testing personnel took place. The outcome was that the UK needed a trade body, the STA formed in 1995.

When did the STA get involved in Standardisation?

In the late 90s, the STA got involved in the standardisation process both with CEN and ISO. There were several poorly written standards in circulation, and at that point, the UK didn't have stack testing professional representing the UK's view on committees. The first committee the STA got involved with was EN 1911, and then EN 13284 which took over ten years to write, validate and publish. Being actively engaged in the standardisation process is still one of the most important aims of the STA

Health and safety

Health and safety was not taken that seriously, and there was no legislation or guidance for the stack testing industry in the UK.

The STA set up the Health and Safety Task Group (HSTG). Days before the initial HSTG meeting a serious incident took place, resulting in the fatality of a stack tester from a fall from height. The incident shook the industry, the STA created the health and safety booklet. The first edition was 12 pages. Following the release and with the input of the HSE, the yellow book was born. The yellow book became the industry standard in the UK, and The Environment Agency adopted it as the industry standard under the MCERTs scheme.

Our Aim

The STA is committed to the advancement of the science and practice of emission monitoring and to develop and maintain a high quality of service to customers.
Its aims and objectives are to:

      • contribute to the development of industry standards, codes, safety procedures and operating principles;
      • encourage the personal and professional development of practising source testers and students;
      • maintain a body of current sampling knowledge;
      • assist in the maintenance of a high level of ethical conduct;
      • seek co-operative endeavours with other professional organisations, institutions and regulatory bodies, nationally and internationally, that are engaged in source emissions testing.

The Association offers a package of benefits to its members which include:

  • Technical advice relating to emission monitoring
  • Conference and exhibition opportunities
  • Seminars and training on a variety of related activities
  • Representation on National, European and International standards organisations
  • Training concerning many aspects of emission monitoring
  • Liaison with regulators, UK and International, many of whom are members.

Clients can be assured that members will offer:

  • The most appropriate protocols and methods
  • Sampling and analysis equipment that is fit for purpose
  • Qualified and suitably experienced personnel

STA Endorsement Scheme

In 1997 the STA was tasked by the members to come up with an endorsement scheme to accredit companies that carry out particulate and gaseous emission monitoring.

The primary purpose of the scheme was to create a high-quality testing approach. The STA endorsement scheme was the forerunner to the MCERTS Manual Testing scheme. To gain an STA endorsement, the company submitted an application form with evidence reviewed by the appointed panel, and an on-site appraisal of company procedures took place, followed by yearly appraisals. Thirty stack testing companies gained endorsements from the STA scheme. The scheme finally closed in 2006 after sufficient companies gained

MCERTS accreditation.

How did the STA get involved with the MCERTS scheme?

The first  MCERTS certificate was handed out at CEM 99 in Warwick by Stuart Newstead of the EA.

The EA looked at extending the MCERTS scheme to manual stack monitoring and approached the STA, and agreed it would create the MCERTs scheme for personnel on behalf of the EA.

The STA and its members put together the framework and syllabus for personnel scheme. MCERTS was formally rolled out in 2002. Since the inception of the MCERTS personnel scheme. The STA has overseen the scheme, this includes being a member of the MCERTS steering committee plus the impartiality committee, and in the early days, Dave Curtis was the chief examiner for the scheme. The STA also became the technical support for the CEM systems MCERTs scheme.


In 1997 the STA with the assistance of IEA Coal research organised the first CEM show which NPL  hosted. CEM ran successfully in the UK for three years, in 2000, CEM, was run in Europe for the first time and is still going strong 19 years on.

EM-CERTS and MCERTS now AQE conference and exhibition

Listening to Members, it became clear that since CEM had moved into Europe, there wasn't a dedicated event in the UK. The STA started a conference with exhibition stands, EM-CERTS (emission monitoring and certification). The format was of one leading conference with technical workshops to be run alongside as well as an exhibition which soon became a success. Soon after the name changed and became the MCERTS conference now known as Air Quality and Emissions, AQE

Task Groups

Stack Emission Monitoring

Technical task group

Technical aspects relating to emission monitoring, including:

  • Methodology
  • Standards
  • Permitting
  • Equipment

Quality task group

The Quality task group specifically addresses those issues relating to improving the value and reliability of the results we provide to our customers as stack testers. The topics routinely discussed include proficiency testing (PT) schemes, relevant CEN standards and EA method implementation documents, EN 14181 guidance, calibration techniques and the availability of calibration gases.  In addition to a large number of stack testing companies, UKAS, EA, process operators and gas supply companies also attend the meetings, enabling issues and topics raised by members to be addressed.

The Quality Task Group is active in producing guidance for members, including the STA Guide to the calculation of uncertainty, and the example uncertainty calculation spreadsheets. Members also have the opportunity to input into EA guidance and CEN and ISO standards.

Also, the Quality and Technical groups undertake specific projects, often with EA or DIUS support, to investigate particular issues related to stack testing methods.

Process Operators task group

The Process Operators Task Group generally meet three times a year in conjunction with the other groups to review developments in legislation and standards and to share practical experience of continuous monitoring, quality assurance and related issues, such as permitting and reporting.   

Health & Safety task group

The safety of those undertaking stack emission monitoring has always been a driving force within the Source Testing Association, and the Health and Safety Task Group is the focus of this work. Since its inception, those involved in this group have strived to produce guidance to the industry on safe working practices and the implementation of safety legislation.   

One of the most recognised publications of this group is the Risk Assessment Guide for Industrial Emission Monitoring, commonly known as the Yellow Book. Its adoption as the safety guidelines for the industry has resulted in its inclusion in the EA guidance and MCERTS scheme, and it has remained a clear and concise guide to the potential dangers of the work we do. Its annual revisions have kept it up to date with the ever-changing legislation while the group has strived to keep it as a simple and practical guide for those up the stack as well as a useful resource for managers, salesmen and process operators.

During the regular meetings, the task group members review changes to existing legislation and proposed new legislation and where necessary advise the STA members as to the potential implications of such legislation. Guidance notes are made available on the website. Accidents in the industry and related industries are reported and discussed.   
Training of stack testers has become a fundamental role of the STA and not more so than through the long-established safety training course. It has become a safety passport for stack testers incorporating the experiences and knowledge of many of the stack testers who have contributed to the health and safety task group. The task group will continue to feed into this essential training.  

We have been fortunate in recent years that there have been no serious accidents in the UK stack testing industry. This trend, we all want to continue, but we must not be complacent. The work undertaken on stacks is ever more vital and demanding. The risks are always present, and as new staff enter the industry, the lessons learnt by more experienced staff must be passed on. The Health and Safety Task Group provides an invaluable resource to the industry to help keep our focus on the serious issue of the safety of those involved in this work.

Equipment suppliers task group

Representing the manufacturers and distributors of particulate and gas CEMs, portable instrumentation, sampling equipment, calibration and gas suppliers, the group focuses on being a  focal point on regulatory, certification and standards issues relevant to emissions monitoring with particular focus on technical issues. The equipment suppliers group provides technical input into UK regulatory consultations related to emissions monitoring, the MCERTS certification process, European and MID standards and is a forum for resolving issues common across equipment suppliers.

The small business task group

Small businesses are innovative, enterprising and flexible. According to the Federation of Small Businesses, they account for 51% of private sector turnover, 59% of the private sector workforce and 60% of all commercial innovations.

The STA Small Businesses Task Group (SBTG) was formed to monitor developments in our industry, and to represent the interests of smaller companies at meetings of the other STA Task Groups.

Our principal objectives are:

  • To promote the interests of members
  • To protect members’ business
  • To identify the continuously changing needs of members

The cost of accreditation to EN ISO/IEC 17025 and the MCERTS Performance Standard is a significant burden for small businesses; however, most have achieved certification to both standards and our members are to be commended for their efforts.


Laboratory Task Group

The laboratory task group was instrument in bridging the gap between emission monitoring standards and analytical procedures and working closely with the Environmental Agency on the development of MCERTS standard for analytical Laboratories.


The STA is committed to encourage the personal and professional development of practising source testers and students and provide training courses on various aspects of emission monitoring.

The training capability has grown over the years following requests from its members to provide independent and impartial training courses. The first course, working at heights, started in 1997.

Current courses include;

Risk Assessment - Industrial Emission Monitoring

Regulatory Monitoring Requirements for Process Operators

On-Site Auditing

Medium combustion plant Directive (MCPD)

MCERTS Personnel competency which includes courses for;

Level 1-Technician

Level 2-Team leader

TE1 – particulate monitoring

TE2 – trace element sampling

TE3 – gaseous monitoring by manual methods

TE4 – gaseous monitoring by instrumental methods

Other courses are available to members which include on-site operation of equipment. All one day course described above can be arranged on-site, and the other more complex courses are arranged where practical.

Courses are held at either our training centre in Hitchin or can be arranged on-site at members premises. More information can be found on all training courses on page xxxx of this annual guide

The Association's headquarters are based in Hitchin, Hertfordshire with meeting rooms, library and administration offices.

Contact details

Contacts: General Enquires Samantha Harvey

Technical Support Andrew Curtis

Telephone: +44(0) 1462 457535


General enquiries sam@s-t-a.org

Technical support andy@s-t-a.org

Web site enquiries  steve@s-t-a.org

Web site: www.s-t-a.org