Background
Chemical technologies are essential to modern life, with over 95% of manufactured goods relying on them. While these substances bring significant benefits, from life-saving pharmaceuticals to enabling advanced technologies, they also contribute to widespread chemical pollution. Hazardous chemicals are now found in everyday items, including water, food, clothing, and furniture.
To manage these risks, countries have developed legal frameworks, monitoring programmes and chemical inventories. However, national efforts alone are insufficient for global chemical management due to two major challenges: (1) long-range environmental transport of chemicals via air and water, and (2) complex global trade networks that obscure chemical flows across jurisdictions.
Previous studies have compiled inventories from Canada, the EU, Japan, and the US, covering over 100,000 industrial chemicals assessed for persistence, bioaccumulation, and toxicity. Yet, this narrow focus excludes rapidly growing producers such as China and India. To address this gap, our study reviewed 22 inventories from the EU and 18 other countries, focusing on industrial chemicals and excluding specialized categories such as pesticides and pharmaceuticals.
Significant data gaps were identified, particularly in Africa and Latin America, where national inventories were largely absent at the time of the study. Encouragingly, some Latin American countries have begun developing inventories, promising new data in the near future.
In total, we identified over 235,000 unique CAS numbers and an additional 120,000 chemicals without CAS numbers. Of these, 70,000 have alternative identifiers, while 50,000 are classified as confidential business information (CBI). Notably, 70,000 new chemicals were added in the past 15 years, reflecting the rapid pace of innovation. Among those with CAS numbers, over 57,000 have not been previously studied and 32,000 CAS numbers are registered exclusively in non-OECD regions, where regulatory capacity is often limited, emphasizing the need to expand assessments beyond OECD countries.
We also examined the chemical types: 157,000 are discrete chemicals (mostly organics), which are measurable in the environment with appropriate analytical methods. Another 75,000 are mixtures, polymers, and UVCBs—complex substances that pose challenges for identification and monitoring. These include:
~5,000 simple mixtures
~17,000 described by production processes
~15,000 derived from fossil or biological sources
~37,000 polymers
Despite today’s advanced analytical capabilities, the detailed compositions of many of these substances remain unknown, representing a longstanding regulatory and monitoring gap.
To explore implications for monitoring, we compared the global inventory against four major datasets. Except for one aquatic dataset (85% overlap), others showed less than 40% overlap. While hundreds of thousands of chemicals are on the market, only tens of thousands have been measured in products and even fewer in the environment. This gap reflects limited analytical coverage, challenges with complex substances, and the presence of poorly studied transformation products.
In conclusion, understanding chemicals on the global market is a critical first step toward managing chemical pollution. The accelerating pace of production and release is outstripping society’s capacity to assess and monitor safety. Urgent action is needed, starting with safer chemical design and expanded global monitoring efforts.
Recorded Lecture
Zhanyun Wang, who is based in the Environmental Risk Assessment and Management Group (ERAM), Technology & Society Laboratory at EMPA, Switzerland, describes his work to understand the global chemical inventory.
Key reading
Wang Z, Walker GW, Muir DCG, Nagatani-Yoshida K. (2020) Toward a Global Understanding of Chemical Pollution: A First Comprehensive Analysis of National and Regional Chemical Inventories. Environ Sci Technol. 54(5):2575-2584. https://doi.org/10.1021/acs.est.9b06379
Muir DCG, Getzinger GJ, McBride M, Ferguson PL. (2023) How Many Chemicals in Commerce Have Been Analyzed in Environmental Media? A 50 Year Bibliometric Analysis. Environ Sci Technol. 57(25):9119-9129. https://doi.org/10.1021/acs.est.2c09353
Persson L. et al. 2022. Outside the safe operating space of the planetary boundary for novel entities. Environ Sci Technol 56: 1510-1521. https://doi.org/10.1021/acs.est.1c04158