Guiding Principles of Responsible Chemistry

For centuries, innovations brought about through chemistry have improved the quality of life for humankind. Advances in chemistry have led to the development of pharmaceuticals, plastics, electronics, and agrochemicals that have benefited society in many ways, but have often come with unintended consequences.² One of the early examples of this pattern involves sodium carbonate, one of the first chemicals produced at an industrial scale using the Leblanc process, which was invented by Nicolas Leblanc. This process transformed the textile industry and laid the foundation for modern chemical industry.³ Sodium carbonate, also known as soda ash, was in great demand in the late 1700s as a feedstock to produce bleaches, dyes, glass, and soap.  

The early methods to produce soda ash were expensive, and in 1783, the French Academy of Sciences—at the behest of King Louis XVI—offered a prize for someone who could produce soda ash from sodium chloride. In response, Leblanc developed a new process to accomplish this goal and was granted a patent to begin industrial production in 1791. Leblanc’s process transformed chemical industry and improved the economy.⁴ While this new process was innovative, calcium sulphate waste was produced, and hydrogen chloride gas was released into the atmosphere, which killed trees, plants, and animals, damaged buildings, and adversely affected human health. Public pressure and legislation, including the Alkali Act of 1863, led to production innovations and more responsible stewardship of the environment. Over time, a novel process to produce sodium carbonate emerged that produced only one principal waste product, calcium chloride, which had substantially fewer adverse effects.⁴ Further refinements of the process led to the elimination of calcium chloride as a waste product. The Leblanc process illustrates what can happen when chemists innovate without sufficiently anticipating harmful consequences.  

It is estimated that over the past century, the Haber-Bosch process for nitrogen fixation has supported roughly 50 percent of the world’s population by producing ammonia for nitrogen-based agricultural fertilizers.⁵ German chemist Fritz Haber was awarded a controversial Nobel Prize⁶ in Chemistry in 1918 for co-inventing the process. However, this inefficient and power-intensive process consumes over 1 percent of the world’s total energy production and accounts for roughly 1.4 percent of global carbon dioxide emissions.⁵ A large portion of the emissions result from the energy-intensive production of the hydrogen feedstock for this process, and most of that hydrogen is currently derived from fossil fuels.⁷ 

Even though the Haber-Bosch process is inefficient, it has proved to be highly reliable and scalable and is still the dominant method for ammonia production because of its practicality and large-scale output. However, in recent decades, there has been a growing effort among chemists, other scientists, policymakers, and the public to utilize systems thinking in relation to ammonia production. Systems thinking means analyzing the entire ammonia value chain and considering all of the interconnected components and how they interact and what long-term effects may result. For example, one of the consequences of fertilizer overapplication is that it leads to environmental challenges such as nitrogen runoff into water bodies, causing eutrophication, and increased atmospheric release of nitrous oxide, a potent greenhouse gas and stratospheric ozone depleter. For chemists, responsible innovation involves research and development programs that lower the environmental impact of this process. Strategies include implementing new sources for hydrogen production that do not rely on fossil fuels, developing new catalysts to reduce energy use, and developing more sustainable methods of fertilizer application to reduce waste.⁵ 

Refrigerants, the working fluids used in refrigerators, freezers, heat pumps, and air conditioners, are essential to our daily lives to preserve food in homes as well as in the transport and retail sectors. Refrigerants are also essential for keeping vaccines cool and maintaining comfortable and safe temperatures in homes and cars. Innovative chemistry led to the production of chlorofluorocarbons (CFCs) in the 1930s to replace toxic refrigerants like ammonia and sulfur dioxide. CFCs quickly proved to be effective, nontoxic, and inert and were also cheap and easy to produce.⁸ However, CFCs also had unintended consequences that were not fully realized until almost a half century later. Due to their inert-by-design nature, CFCs are insoluble in water and do not react with hydroxyl radicals that scavenge many tropospheric pollutants. As a result, CFCs have long atmospheric lifetimes, eventually entering the stratosphere where they photochemically decompose to produce chlorine radicals that participate in catalytic-chain ozone-depletion mechanisms. The rapidly diminishing stratospheric ozone layer became so concerning that CFCs were phased out by the Montreal Protocol.⁹  

Hydrochlorofluorocarbons (HCFCs), which have shorter atmospheric lifetimes,⁸ were introduced as replacement compounds. While less damaging, HCFCs still caused ozone depletion. Next, hydrofluorocarbons (HFCs) were developed and adopted as long-term replacement compounds because they have ozone-depletion potentials near zero (HFCs contain no Cl atoms). In working to solve the ozone-depletion problem caused by some refrigerants, the chemistry profession has mostly neglected to use systems thinking to consider other unintended consequences. Specifically, HFCs have been shown to have large global-warming potentials, so HFCs are also being phased out.⁸ Innovation is ongoing, now benefiting from systems thinking approaches, to find the next generation of refrigerants, as well as novel approaches to refrigeration that move beyond standard vapour-compression technologies. The issue has become pressing due to rapidly growing demands for refrigeration and air conditioning as climate change worsens.