The biennial global interlaboratory assessment on POPs is a key element of quality control/quality assurance for any chemical analytical laboratory and has an important role under the UNEP/GEF GMP projects. The interlaboratory assessments are not restricted to countries participating in the projects, any laboratory can register to participate.
To provide reliable monitoring information for the Parties to the Stockholm Convention, the latest version of the guidance document (2019 version UNEP/POPS/COP.9/INF/36) aims to “confirm a 50% decline in the levels of POPs within a 10-year period”. This means that laboratories must be capable – at any time – to analyse samples for POPs within a margin of ±25%. Interlaboratory exercises are used to assess the effectiveness of quality assurance/quality control practices among the participating laboratories and to provide a measure of interlaboratory comparability. This usually involves the circulation and analysis of a common standard or reference sample, often at two or more concentration levels. In order to determine the ’true’ concentration of POPs in a sample, a chemical laboratory must be able to prove that it is capable to identify and quantify chemicals of interest at concentrations of interest.
The first round of interlaboratory assessment was performed from 2010 to 2011 on the analysis of 12 initial POPs listed under the Stockholm Convention with 104 laboratories registered from all UN regions. 111 laboratories participated in the second round, from 2013 to 2014 and analysed also the nine new POPs listed in 2009. The third round interlaboratory assessment completed its work in 2017 with 175 laboratories. The fourth round launched in 2018 with 147 laboratories registered and concluded mid-2019.
The interactive Dashboard gives an overview of the distribution of the participation of the laboratories, per region over the 4 rounds, showing how many labs registered to be evaluated and how many submitted results for the assessment, as well as the number of countries where the laboratories are located.
In total, 289 laboratories participated in the four rounds with eight test solutions and eight test matrices, covering all UN regions including 1/3 of commercial labs. Between 38 to 55 countries participated in each of the four rounds with a total of over 2950 samples analysed.
Over ten years and four rounds, the UNEP/GEF interlaboratory study has gained international reputation. The biennial global interlaboratory assessments on POPs have become an internationally accepted global standard and the network of POPs monitoring specialists and POPs laboratories should be considered a key component in creating the conditions for sustainable monitoring of POPs, in the project participating countries, and globally in the future. Visit the POPs laboratory Databank.
Key findings
- The interlaboratory assessments, which aimed to assist laboratories to improve the quality of their analyses and to provide a measure of the interlaboratory comparability, shows that about 80% of labs do not have the necessary experience to analyze a large number of POPs and cannot generate global comparable and reliable data for the effective evaluation.
- There is a need to continue working on improving the quality of POPs analysis worldwide. This is evident considering that at each meeting of the COPs new POPs are included to the Convention, and there are already listed POPs, such as polychlorinated naphthalenes (PCNs) and chain chlorinated paraffins (SCCPs), which were not included in the interlaboratory assessment.
- Laboratories that participated more frequently and included a broader spectrum of POPs and test matrices improved their performance or performed better than laboratories that participated only once.
- There were some limitations with the analyses of certain POPs, regionally, for example the analyses of PFAS in Africa and GRULAC, additional to the analyses of brominated flame retardants in Africa.
- Regular interlaboratory assessment including different combinations of POPs and matrices, are for control of assessment, the routine analyses of the laboratories should be the same used for generating and reporting results.
- To improve and ensure better POPs analyses, a good quality of laboratories is needed including the instrumentation as well as all the aspect of extraction, clean-up steps, skilled personnel, material, and consumables (certified standards, high-purity solvent, and high-quality gases). It is also important throughout normal operations to apply self-control, quality assurance measures and quality controls charts.
- To ensure sustainability and maintenance of the infrastructure and instrument the laboratories need to follow a business plan of routine POPs analyses.
Projects Reports
As they get published, the sectoral, regional and overview reports of the the UNEP/GEF projects "Implementation of the POPs Monitoring Plan” and “Continuing Regional Support for the POPs Global Monitoring Plan under the Stockholm Convention" will be added on the POPs GMP Reports page.
