A growing number of companies producing per- and polyfluoroalkyl substances (Pfas), often called "forever chemicals" because they do not break down in the environment, are increasing production to meet rising demand from the artificial intelligence (AI) industry, according to a report by the Swedish watchdog ChemSec. Despite growing concerns about their health and environmental risks, a survey of the 10 largest Pfas manufacturers found that most are planning to expand their production. These chemicals are used in various applications, including datacentre cooling and semiconductor manufacturing, both of which are experiencing rapid growth due to the AI boom. Pfas are used in next-generation datacentre cooling systems, which are marketed as more energy- and water-efficient than traditional methods. These systems use Pfas with low boiling points to cool servers by immersing them in a fluid that turns into vapor when heated. This vapor is then cooled and recirculated, reducing the energy and water needed for cooling. Meanwhile, in semiconductor manufacturing, Pfas are used in hundreds of steps of the fabrication process, making them essential for producing microchips needed for AI hardware. Critics warn that the increased production of Pfas could undermine recent efforts to regulate or phase out these chemicals in parts of Europe, the UK, and the US. Companies such as Japan's Daikin, France's Arkema, and the US-based Chemours are expanding their operations to meet the rising demand. Some of these companies have faced legal challenges over Pfas contamination, yet they continue to promote their use in new products and technologies. Meanwhile, a few companies, such as Swiss firm Archroma and German giant BASF, are moving away from Pfas production. Pfas are also being used in the production of lithium-ion batteries, which power electric vehicles, laptops, and smartphones. Companies like Gujarat Fluorochemicals in India and Chinese firm Dongyue see batteries as a key growth area alongside datacentres and semiconductors. However, the environmental and health risks of Pfas remain significant. These chemicals are resistant to degradation and can accumulate in the environment, leading to contamination in air, water, and soil, and ultimately in the human body. Research has found Pfas in nearly every person's blood worldwide, and they have been linked to various health issues, including cancer and liver disease. ChemSec has urged company leaders to test their own blood for Pfas, highlighting the personal impact of these chemicals.