Green Chemistry

Waste treatment

The management of pharmaceutical waste involves dealing with various forms of waste, including discarded peripheral equipment (test kits, dispensers, syringes, etc.), expired products, packaging and manufacturing waste. Effective methods for disposal are crucial to prevent pollution and protect the environment. Regulatory bodies and waste management strategies play a significant role in ensuring the proper handling of (usually hazardous) pharmaceutical waste.  

When considering waste management is important to refer to the EU Waste Framework Directive 2008/98/EC. This directive outlines the 'waste hierarchy,' which recommends how to reduce the depletion of natural resources and prevent environmental degradation. It includes measures such as prevention, reduction, reuse, recycling, and disposal. There is a degree of flexibility when defining these waste management actions so to be broadly applicable, but it can lack clarity on certain aspects. Chemical manufacturing plants must manage hazardous wastes appropriately.

Reuse is not an obvious route to waste prevention in terms of pharmaceutical products, but it could be applied to dispensers and packaging. In manufacturing, reaction catalysts are often reused, especially in the context of flow chemistry.

Recycling is routinely performed on packaging via household waste collections, but it also applies to manufacturing plants. Solvents are often recycled by distillation. More can be done to improve recycling rates with specific design innovations and improved, more widespread recycling infrastructure. This is being encouraged through policies such as the circular economy.

Recovery usually refers to waste incineration where energy is reclaimed, often by heating water to drive a steam turbine. Materials are rated as more valuable than energy, which is why recovery is after recycling in the waste hierarchy. After all, a recycled material could be incinerated (with energy recovery) later once one more use has been acquired from it.

Disposal in landfills, or litter, is an unacceptable loss of material value and should be avoided. Pharmaceuticals are metabolised as part of their intended function and excreted. This form of disposal is unavoidable. When chemicals are released into the environment as part of their function, they shall be biodegradable, and ideally made from renewable resources too. Then they are compatible with a circular economy. Incineration without energy recovery is also categorised as disposal because no value is retained. Many single use medical devices will be incinerated because of contamination. Public health must be the priority but in some instances sterilisation could be more appropriate.

Solid waste

Solids represent our typical idea of waste as a consumer, be it plastic, glass, paper, garden or food waste. The solid waste produced by the pharmaceutical industry includes a variety of waste streams that can negatively impact the environment and public health if not properly managed. These waste streams result from the production, use, and disposal of pharmaceutical products. As well as hazardous chemical waste emerging from manufacturing plants there is also packaging and unused medicines to consider.

The idea of a circular economy (Ellen Macarthur Foundation, 2024) gives an aspirational framework to develop a waste-free pharmaceutical supply chain.  Alshemari et al. (2020) investigated ways of eliminating waste from the pharmaceutical supply chain and determined a variety of strategies that could be implemented. Some of their waste management ideas are listed below.

Ultimately, the reduction of solid waste requires cooperation by various organisations throughout the supply chain. Open channels of communication leads to a better understanding of where issues are, and makes it easier to find solutions.

Waste water

Water is a critical resource in the pharmaceutical industry, serving as a solvent and cleaning agent but also for temperature regulation (e.g. cooling). However, improper management can lead to significant environmental pollution. Waste water from pharmaceutical manufacturing plants can be contaminated with organic and inorganic chemicals, metals, pharmaceutical compounds, and often mixture of all of them. The management and treatment of aqueous waste from the pharmaceutical industry in Europe involves several key considerations and technologies to ensure environmental protection and compliance with regulations. Efforts to optimise water use in processes and minimise wastewater are also essential for aligning with green chemistry principles. 

Best Available Techniques for managing wastewater and waste gases in the chemical sector have been established, highlighting the importance of environmental management systems, water saving, wastewater management, collection, and treatment. Understanding the composition of the pollutants is crucial for implementing the most effective treatment techniques and ensuring compliance with environmental standards. 

The importance of effectively managing wastewater in the pharmaceutical industry cannot be overstated, as it plays a critical role in preventing the discharge of toxic substances into the environment. These substances, if not properly treated, can have detrimental effects on aquatic ecosystems, including promoting antibiotic resistance and causing endocrine disruption among aquatic species. Furthermore, ensuring that pharmaceutical wastewater is appropriately treated is essential for compliance with stringent environmental regulations, which aim to safeguard public health by preventing the contamination of drinking water sources. By investing in efficient wastewater treatment technologies and strategies, the pharmaceutical industry can mitigate its environmental impact and ensure long-term ecological and public health benefits.  

Air emissions

Taking the EU as a whole, gaseous wastes represent a surprisingly large amount of the material lost from the economy every year, considerably more than the material either recycled or sent to landfill. Much of this gaseous waste is from burning fuel to make (primarily) carbon dioxide and water, but other chemicals also enter the air from manufacturing and product use. Air pollution has various forms, including particulate matter (microscopic solids dispersed in the air) and Volatile Organic Compounds (VOCs). VOCs encompass a diverse group of chemicals originating from both human and natural sources. VOC emissions are generally decreasing in Europe (EEA, 2024), but VOC emissions from the chemical industry are stubbornly resistant to this trend. Anthropogenic sources of VOCs include refrigerants, fuels and fragrant products (including household cleaning products) and industrial solvents.

Indoor VOC pollution primarily consists of substances like ethyl acetate, formaldehyde, and toluene. These emissions, like all VOCs, pose a substantial environmental threat, contributing to issues like global warming, ozone layer depletion, and smog/haze formation. Furthermore, the high toxicity and carcinogenic potential of most VOCs presents an often underestimated health risk, underscoring the urgency for effective VOC management strategies. This is the motivation behind the reformulation of asthma inhalers. Amazingly, half of pharmaceutical company GSK's carbon footprint comes from the salbutamol inhaler propellant (GSK, 2023). Research has developed a low impact delivery system that is undergoing clinical trials.

As for industrial emissions, various techniques for VOC emission control are documented, including both destruction-based and non-destruction-based methods. Li et al. (2023) meticulously reviewed these technologies, delineating their underlying principles, benefits, drawbacks, and current research focal points. This comprehensive analysis highlighted the necessity of adopting and refining VOC abatement methods to mitigate their environmental and health impacts effectively.