Flow chemistry has changed chemical process designs toward process intensification and is generally considered as green methodology. In this connection, this perspective provides a more critical and holistic view about the sustainability of flow chemistry by introducing both simple and complex holistic tools for environmental quantitative assessment on sustainability and providing examples of how they were used for flow chemistry. The latter also shows a critical assessment of what flow chemistry can add to make chemical processes more sustainable. With the increasing complexity of assessment, green chemistry metrics, life cycle assessment methodology, and circular transition indicators are discussed. In this way, the sustainability of flow chemistry is assessed first on the level of a reaction only and then moving to a process level and beyond. Flow chemists are very aware of the principles of green chemistry and their simple metrics. Yet, they hardly use life cycle assessment, and quantitative circularity analysis has not been made. When those assessments are used, it is usually done by researchers with an ecology background. This perspective aims to make flow chemists aware of the opportunities that complex environmental assessment can provide and that protecting our planet requires a holistic sustainability consideration. The perspective critically states what each of the three types of assessments can do and what their limitations are.

The vitamin D 3 flow-chemical process is a good route for exercising circularity in chemistry; as the complex chemistry of this reaction limits the highest yield to only 25%, a recycling operation becomes mandatory. In this context, this research applies, for the first time, a circular economy assessment to a flow chemistry process, including reaction and separation. This is undertaken on the example of the photo-flow-chemical synthesis of vitamin D 3 , previously developed by our group. In the research reported here, we develop a separation process to recycle the unreacted starting material 7-dehydrocholesterol after the photo-flow irradiation. We use acetonitrile for separation, instead of methanol, in the industrial process. In just one run, 90% of vitamin is extracted using dry acetonitrile as a separation solvent at 30 °C. A cumulative extraction efficiency of >99% is achieved after a second extraction step. The acetonitrile separation process connects directly to the subsequent vitamin crystallization using the same solvent. This eliminates the need to evaporate methanol in the industrial process; rather, the product is obtained just by cooling down. The Material Circular Indicator has been used as a central metric, and we needed to redefine this circularity metrics proposed by the Ellen MacArthur Foundation's CE100 program to the world of flow chemistry. Rather than being able to take the parameter of lifetime and utility used in the original C100 definition, the frequency and dose of usage of medicinal products are taken here, both of which are connected to chemical productivity and waste generation. To explore the application of this adapted methodology to other pharmaceutical production processes, the results for the proposed vitamin D 3 flow-chemical process are compared with five processes for producing vitamins, painkillers, and an antibiotic. It is shown that the vitamin D 3 flow chemistry process with the new separation achieves a Material Circular Indicator of 0.94, a recycled fraction mass above 0.95, and an energy demand reduction by a factor of 2.

This chapter addresses two major challenges for mainstreaming life cycle management that are intrinsically linked: collaboration and communication.To this end it is argued that in order to radically increase the take up of life cycle based approaches in business and government, life cycle professionals need to enhance global collaboration among themselves, as well as with others and communicate to a wider set of stakeholders. The chapter makes the case that the life cycle community does not have a home, and thus currently does not exist as one coherent and clearly identifi able stakeholder. It concludes that successful communication on behalf of and with the community can only be achieved when the community is formally organized. To this end the newly established Forum for Sustainability through Life Cycle Innovation is presented as a possible way to overcome the outlined gaps and challenges.

Although Life Cycle Management (LCM) is becoming commonplace in larger corporations it is far from mainstream. To achieve sustainable production and consumption patterns, LCM needs to be taken up by whole supply chains that include small and medium sized enterprises (SMEs). From a business perspective, this represents a competitivity issue, as these SMEs are increasingly under pressure from clients and legislators to provide more information about the environmental impacts of their products, and to take responsibility for them both up and down the value chain. Therefore a sector based and regional approach is needed to foster the implementation of LCM in SMEs. This has been done in Northern France, where professional support organizations, including clusters, business federations and Chambers of Commerce, have come together under the auspices of the LCA Platform to explore ways to help businesses to adopt LCM. Nine pioneer sectors, textile, seafood, packaging, mechanical, food, wood, construction, recycling and renewable energies, have undertaken an ambitious project to integrate LCM into their business. The methodology for all nine sectors follows fi ve major steps: benchmark, sector maturity assessment, needs identifi cation, action plan and implementation.Keywords Life cycle assessment • Life cycle management • Regional development • Sector-based approach • Small and medium sized enterprises • SMEs

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