This article is part of Orbia’s Megatrendsetters blog series, which explores how Orbia’s solutions are driving the transformative forces, or “megatrends” that are advancing our society, from decarbonization and the circular economy to shifting supply chains and agribusiness to global water and digitalization. Learn more about our medical propellants.
For decades, inhalers have been a lifeline for millions living with asthma and chronic obstructive pulmonary disease (COPD). These devices, which deliver medication directly to the lungs, rely on specialized gases—known as propellants—to function. The story of medical propellants is one of scientific innovation, public health and, increasingly, environmental responsibility.
The first pressurized metered-dose inhalers (pMDIs) were invented 70 years ago, using chlorofluorocarbons (CFCs) as propellants. CFCs were ideal for their stability and effectiveness at delivering medicine evenly, but by the late 1970s, scientists discovered that these chemicals were depleting the planet’s protective ozone layer. The industry galvanized around this: CFCs were phased out by the 2000s and hydrofluoroalkanes (HFAs) replaced them in inhalers. However, while HFAs solved the ozone problem, they remained potent greenhouse gases, with a global warming potential over a thousand times more powerful than CO₂.
Today, inhalers must go through a second transition to incorporate low global warming potential (GWP) medical propellants.
How Orbia is Leading the Transition to Low-GWP Medical Propellants
Thirty years ago, Orbia’s Fluor & Energy Materials business introduced the most widely used propellant in inhalers: Zephex 134a. Today, it is used in two thirds of all inhalers, enabling 100 million patients to access their lifesaving medicine each year. However, even as Zephex 134a became the global standard, the team recognized the need to continue to improve it and began R&D on a more climate-friendly solution.
Orbia scientists screened many different molecules to identify one that would significantly reduce the global warming potential, be safe for human use and be able to scale industrially. They selected HFA-152a as the most promising candidate. The initial selection work was followed by ten years of thorough toxicology studies to demonstrate the molecule’s safety and create the commercial product of Zephex 152a. The molecule’s partially hydrogenated structure makes it chemically vulnerable to rapid atmospheric oxidation, dramatically shortening its lifetime compared with the highly fluorinated and chemically shielded HFA-134a. This translates to a 90% less global warming potential than Zephex 134a.
Supporting Customers and the Broader Industry
Transitioning to new propellants is a complex process, requiring not just new formulations and manufacturing techniques but also regulatory approvals and clinical trials.
Orbia’s technical teams have worked closely with component manufacturers to ensure compatibility and safety, accelerating the learning curve and enabling faster regulatory approvals. The company has also obtained licenses for clinical batch manufacturing, helping customers bring new, more sustainable inhalers to market, more quickly. This is especially important as the industry prepares for further implementation of the EU F-gas regulations, which were updated in 2024 and aim to significantly reduce the global warming potential of inhalers.
This momentum is now carrying into the next phase of the project. Orbia is ramping up production of Zephex 152a, while continuing to supply Zephex 134a, to ensure a reliable supply and smooth transition that meets the evolving needs of the pharmaceutical industry, putting patient medicine continuity at its core. The first ISO tank delivery of Zephex 152A was completed in October 2025, with broader market availability anticipated in 2026. Additionally, a large-scale facility at Orbia’s Rocksavage site in the U.K. is set to be completed by the end of 2026. As these efforts scale, Orbia continues to explore new initiatives to advance sustainability across the industry—such as propellant recycling programs—ensuring long-term positive environmental impact alongside innovation.
An ISO tank containing 17 tonnes of Zephex 152a was delivered to Kindeva’s new facility in Loughborough, U.K. in October 2025, marking Orbia’s first large-scale commercial delivery of the low-GWP propellant.
New low GWP propellants are essential for customers including Chiesi, Kindeva, Bespak and GSK, to meet their sustainability targets. For example, GSK aims to reduce its emissions by 80% between 2020 and 2030, a goal only achievable by switching to low-GWP propellants like Zephex 152a.
The transition to low-GWP medical propellants is more than a technical challenge—it’s an opportunity for the pharma industry to combine clinical innovation with climate leadership. Orbia’s investments, partnerships and focus on advancing sustainability are helping to drive this transformation, ensuring that the future of patient care is also a future of planet care.