How the UK’s defence laboratory keeps the world safe from the threat of chemical weapons

The Defence Science and Technology Laboratory (DSTL) at the Ministry of Defence’s site in Porton Down is the only lab in the UK designated by the Organisation for the Prohibition of Chemical Weapons (OPCW) to support its investigations into suspected incident of chemical weapons use.

In 2024, the laboratory marked 25 years since it was first appointed as a designated lab for the OPCW and in that time its analyses and evidence have supported investigations in the UK and all around the world. Senior analytical scientist Sarah reveals how the lab works with the OPCW to uphold the chemical weapons convention, and just what it takes to become a designated lab.

What does it mean to be an OPCW Designated Laboratory?

Designated Laboratories are appointed by the OPCW to support its investigations into the suspected use of chemical weapons. So obtaining that title means that a laboratory is one of the best in the world for analysing samples to identify chemical weapons, and that it’s entrusted to do that work for the OPCW.

There are approximately 30 OPCW Designated Laboratories worldwide. In the UK, DSTL is the only Designated Laboratory for the OPCW. The evidence we provide ensures that signatories^[1] to the CWC uphold their obligations under the convention and that perpetrators of chemical weapons attacks are held to account. Ultimately, we help to make the world a safer place against the threat of chemical weapons.

I have had the privilege of being part of DSTL and the OPCW’s Designated Laboratory network for nearly 20 years. The shared sense of purpose, open knowledge sharing and close collaboration that exists within this small international community makes it feel like family. I think this is a real strength of the network in sharing and promoting best practice.

How does the OPCW use designated labs in its work?

Designated Laboratories support the OPCW’s investigations by analysing samples to help determine whether chemical weapons have been used, which ones have been used, and if humans have been exposed to these deadly chemicals.

Designated Laboratories work collaboratively, supporting the OPCW in research and sharing knowledge and skills to strengthen the network.

They also support the OPCW with proficiency testing, assisting in sample preparation and in evaluating the annual proficiency tests. This is essential to maintain this international network of high performing laboratories for identification and attribution of chemical weapons.

How hard is it to become a designated lab?

The OPCW set extremely high standards to qualify for designation. Laboratories must pass annual proficiency tests run by the OPCW and hold accreditation, to international standards (ISO/IEC 17025 or equivalent), for analysis of chemicals relevant to the CWC in typical sample types.

There are separate proficiency tests for environmental and biomedical samples. Labs are assessed once a year on both environmental and biomedical samples. In every test a lab must analyse six blinded samples to identify any chemicals, or markers of human exposure, relevant to the CWC, and they must return the results within 15 days.

The tests mimic actual scenarios we might encounter, so the sample matrices are realistic and complex. The CWC covers millions of reportable chemicals, so multiple analytical techniques are necessary to screen environmental samples. Highly sensitive chromatography–mass spectrometry methods are necessary to detect trace level markers of human exposure to chemical weapons in blood and urine. We also have to synthesise chemicals, including those of high toxicity, to elucidate new chemical structures, metabolites and markers of human exposure.

Mentoring and training is critical to develop the psychological safety you need to handle dangerous materials

For environmental samples, a lab will lose its designation if it fails to identify more than one of the chemicals over three consecutive tests. For biomedical samples, it’s over two consecutive tests.

In recent environmental tests, the pass rates were 40–50%. So it is not uncommon even for experienced Designated Laboratories to be suspended for failing to meet the standard required and it takes a minimum of 1.5–2 years to regain their designated status.

When the team participate in the tests, the pressure is palpable. Yet it also comes with a sense of excitement and duty, which bonds the team. We know that we are honing the skills we will need when a real investigation starts.

In the 25 years since DSTL obtained its designated status it has never once failed to meet these requirements. Only two other laboratories worldwide can say the same, and that’s a source of huge pride for us.

So what happens when the OPCW starts an investigation?

When the OPCW requires off-site analysis to support an investigation, its Director-General reaches out to the network of Designated Laboratories for assistance. Typically, at least two laboratories will independently support an investigation.

A multidisciplinary team of analytical chemists, synthetic chemists, quality specialists and senior advisors is then assembled by the lab to support the investigation. It’s the chemists’ job to act with impartiality and provide the highest quality scientific evidence to fulfil the purpose of the sample analysis. This may be to confirm the presence or absence of a chemical weapon, find any evidence of human exposure, or to provide chemical forensics evidence which may help identify a likely perpetrator of a chemical weapons attack.

How do you deal with the risks of handling these deadly materials?

Safety is paramount! When I first joined Dstl, I was struck by the sense of team and community towards ensuring our collective safety. Our positive safety culture focuses on keeping each other safe and our personal responsibilities, which ensures we all go home safely every evening.

Our commitment to mentoring and training is critical to develop the psychological safety you need to handle dangerous materials. My own mentors were calm, competent and supportive, and they gave me the skills and confidence to work safely with toxic chemicals.

Our work helps to make the world safer

Importantly, DSTL’s new state of the art Chemical Weapons Defence Centre has specially designed high containment chemical laboratories. This customised infrastructure maximises safety and security in handling of highly toxic chemicals.

Working with dangerous materials affects people in different ways, and we manage it in different ways. For me, it helps to focus on the importance of our work, which is supported in a safe, highly controlled and regulated environment. Our work helps to make the world safer, such that we can deter and protect people from experiencing the fear and lethality of chemical weapons.

What has changed since Porton Down became a designated lab in 1999?

Chemical threats relevant to the CWC continue to evolve – existing chemical threats endure, and new threats emerge. For example, a mixture of potent opioids, carfentanil and remifentanil, was used by Russian Special Forces in the Moscow Theatre Siege in 2002. In Syria in the 2010s, the nerve agent sarin, chlorine gas and the blister agent sulfur mustard were all used. Some of these chemical weapons date back to the first world war.

More recently, we have seen the assassination of Kim Jong-nam using nerve agent VX, and a new type of nerve agent, Novichok, used in the attempted assassination of Sergei Skripal in Salisbury and production of the toxin ricin by the perpetrator of the Southport attack in the UK.

The equipment and techniques that we use have also changed significantly. Chromatography–mass spectrometry instruments have become much more sensitive and accurate, and also much smaller. We have seen the explosion and extensive adoption of liquid chromatography–mass spectrometry and high resolution-mass spectrometry. These advances mean we can achieve identification at trace levels, with higher confidence and for a wider range of analytes.

DSTL provided analysis to identify uses of the nerve agent sarin in Syria and Novichok in Salisbury, UK

Our laboratory has also invested in techniques such as elemental and stable isotope analysis, to enable chemical forensics. This allows us to look at the chemical profile or characteristics of a sample, which can help to determine where it was made or who made it.

What investigations have you worked on?

Some of the most well documented are the investigations in Syria and Salisbury. DSTL provided analysis of both human and environmental samples to identify the chemical weapons used, for example the nerve agent sarin in Syria and Novichok in Salisbury, UK. Our evidence for investigations in Syria informed decision makers in the UK, enabling the UK to confirm, condemn and deter future use of chemical weapons.

We supported UK Police investigations into the Salisbury and Amesbury poisonings, following the attempted assassination of the former Russian spy Sergei Skripal. Our analytical findings were verified by the OPCW. DSTL’s scientific evidence helped the police to identify the Russian perpetrators, leading to expulsion of Russian diplomats by the UK and its allies.

What else do you do at the lab besides helping the OPCW in its role?

Lots of things! We provide the UK’s Chemical and Biological Analysis and Attribution Capability (CBAAC) which operates all day, every day to analyse samples in support of Defence and Security investigations of chemical or biological weapons use, both at home and overseas. We also support environmental recovery operations involving areas affected by chemical or biological weapons contamination.

DSTL provides UK sovereign capabilities for chemical and biological defence research to protect the UK, our people and our allies. This research underpins our ability to deliver critical roles for Defence and Security through developing and pulling through new technologies and tools. We work extensively with academia, industry, our NATO and other international partners to cultivate a vibrant research base, which feeds our operational and testing capabilities.

As told to Philip Robinson