Green Chemistry Pedagogy

3.1 GC Academic Programs

Over the last 20 years there has been an explosive growth in GC courses and programs. The article titled “The Ivory Tower Goes Green” [23] describes how academic programs infused GC into chemistry curricula in 2008. Fast-forwarding to 2015, according to the ACS GC Web site [24], there are now 41 GC academic programs in 25 US states. However, this is a fledgling number since according to the ACS [25], there are 681 ACS-approved chemistry programs in the United States. Internationally, GC also surged academically, and by 2015 there were more than 33 GC programs offered by 16 countries and organizations.

3.2 High School GC

Very little has been published regarding GC in the secondary curriculum, and there is a need for novel activities, experiments, and case studies. One way to publicize GC in high school is through outreach. GC outreach in the K-12 system is becoming more common as described in a write-up on Beyond Benign [26], a foundation that advances GC in New England. National Chemistry Week “Celebrating Chemistry” pamphlets [27] have touched on GC in its outreach for Mole Day. GC outreach is also supported by the Green Chemistry Institute [28].

In high school chemistry curricula, although the term “green chemistry” has yet to be written into NGSS standards [29], at least “sustainability” appears. The NSTA has published a few quality GC papers in its journals that cover both K-12 science teaching and college teaching. Most of the NSTA articles regarding GC center on stimulating student interest in chemistry while imparting a positive image of the field and its relevance to everyday life. For example, in its “Career of the Month” column, Megan Sullivan [30] describes what its like to be a Green Product Chemist, by summarizing her interviews with several green chemists. She provides a very relevant and inspiring example in delineating how Nike Corporation used professionally trained R&D green chemists to develop a “greener” rubber by identifying and replacing hazardous chemicals with naturally sourced chemicals.

Ken Roy also authored a number of articles touching on GC. In the column titled “Scope on Safety,” in the article, “Greener Is Cleaner and Safer,” Ken Roy [31] informs readers of the 12 principles of GC, in an effort to reduce risks and accidents, especially in middle school. In another article titled “Safer Science,” Roy [32] discusses sustainable safety practices being encouraged by the EPA (Environmental Protection Agency)that cover GC procedures on how to properly select and use commercial cleaning products with the intent of decreasing fumes and particulates that cause indoor air pollution. In another article titled, “Is Green Cleaner,” Roy [33] argues that “students at the middle school level are at greater risk when exposed to toxic chemicals.”

A 2010 paper titled “Green Root Beer Laboratory [34]” appears to be the first actual GC lab published in an NSTA journal. Students formulate a green root beer using local products (root beer extract) and recycled materials (plastic bottles). Content knowledge addressed includes using acid–base chemistry and two brewing methods: (a) dry ice and (b) yeast. Unfortunately, the latter process produced up to 0.5 % ethanol rendering the product unfit for child consumption.

However, in an NSTA Green Science column article [35] “Green Beauty,” the author writes that “many cosmetics contain ingredients that are linked to health problems and environmental concerns” and issues one warning after another related to chemicals that the Food and Drug Administration (FDA) deems safe. The author’s opinion that oxybenzone in sunscreens is dangerous is overstated because not only does the FDA consider it safe, but more importantly, it reduces skin cancer risk caused by the sun’s UV radiation. When teaching the same material, a green chemist might instead invoke a risk/reward strategy in evaluating the value of oxybenzone in sunscreens. Using “green” to misinform a young audience may induce chemophobia at an early age.

Although Mandler et al. [36] did not explicitly focus on GC, their work arguably promotes both green and sustainable literacies by devising and deploying a unit that integrated environmental and analytical chemistry, thus transforming content into a relevant and real-world context. The unit “I Have Chemistry with the Environment” consisted of two modules, one on drinking water quality, and the second on the greenhouse effect. Results indicated that students underwent positive changes in both attitudes toward chemistry and were better motivated to learn chemistry.

3.3 College General Chemistry

Little has been written regarding how to incorporate GC into undergraduate general chemistry and therefore this section will review in depth GC pedagogy used in labs, lecture, a case study, and a demonstration. Generally speaking, published work involves two kinds of pedagogy: (a) the chemistry content subfield pedagogy which is primary and (b) the GC content pedagogy which is ancillary, but which also carries the function of motivation. Hence, GC crosses the cognitive mode and also enhances the affective side by increasing motivation. In short, GC primarily serves as a vehicle to teach chemistry subfield content, and secondarily GC content.

3.4 GC in Other Papers

In another paper, Klingshirn et al. [43] published a green experiment to determine the formula of a metal hydrate, the authors choosing copper(II) chloride to replace the more dangerous barium salt.

In a second paper, a greener version [44] of the traditional Blue Bottle demo was developed. Optimizing the demonstration involved substituting sodium bicarbonate for potassium hydroxide, making the solution less caustic. In addition, ascorbic acid substituted for glucose, and additional copper sulfate pentahydrate was added. The modified version was not only safer, but it also reduced the amount of waste.

A green colligative property experiment [45] suitable for general chemistry class was reported in 2005. Traditional dangerous aromatic solvents like naphthalene are replaced by fatty acids like stearic acid, to measure the molar masses of solutes like lauric, myristic, and palmitic acids by freezing point depression. All of the fatty acids employed were nonhazardous, inexpensive, and had properties similar to their traditional counterparts. GC principles were demonstrated by using fatty acids originally derived from biomass rather than petroleum, and recovering and recycling them for further use so that waste was reduced or eliminated.

In summary, only a few papers have addressed GC high school and GC general chemistry, and there is a need for more work to be published. One possible avenue would be to integrate GC into the Nature of Science for science education students. GC case studies can also be built from published papers such as Jansen’s [46] on the cost of converting a gasoline-powered vehicle to propane.

3.5 Courses and Curricula

In this section, we will be reviewing published work regarding GC courses and curricula. “Pre-curriculum” emergence of GC began in 1998 [47] when a collaboration between the ACS and the EPA created the Green Chemistry Educational Materials Development Project. The focus of many early papers such as the one published in 2000 by Hjeresen et al. [48] was to provide general information on GC, explain why it is important, and connect it to the environment. In some early papers covering GC chemistry curricula, some researchers advocated the view that GC was not a separate field of chemistry but a common component of all fields, more akin to ethical conduct, and a part of social and scientific responsibility. Another idea advanced regarding GC in the curriculum was that stand-alone GC courses were not viable as electives because they would draw few students, they were expensive startups, and they required trained faculty. Therefore, in most situations the best choice was to integrate GC within existing courses, which was the path chosen by Cann and Dickneider [49] who in 2004 published an article explaining how GC can be integrated into an existing curriculum. Their “infusion” method bypassed the rigor of new course scrutiny, and efficiently incorporated real-world GC examples into several courses in the chemical curriculum, including general and organic chemistry.

Later, in 2006, Braun et al. [50] published a commentary paper that originated from the July 2005 third annual ACS Green Chemistry Summer School (GCSS) held in Montréal, Québec, Canada. The paper also advanced the viewpoint that GC is not a distinct discipline or separate field of chemistry, but instead serves as a guiding principle for social and scientific responsibility leading to sustainability. According to the authors, as such, academic chemists should perform the difficult task of modifying their curricula so that GC becomes an important component. By doing so, they could strengthen the partnership between interdisciplinary scientific fields. Over the years as GC gained ground, GC courses became stand-alone and instances of GC programs became widespread. Obviously, GC has evolved from being considered ethical conduct into stand-alone programs across the globe.

3.6 GC Courses

Collins [51] describes the first GC course published in Journal of Chemical Education (JCE). The course titled “Introduction to Green Chemistry” demonstrated how GC evolved out of environmental programs at Carnegie Mellon University. The course was taught in 1992 and 1993 to upper-level chemistry undergraduates and graduate students as part of an environmental initiative across the university curriculum. The author noted the power of GC to serve as a vehicle imparting new relevance to chemistry. The course also helped students view chemistry as a positive force in a field whose name was often synonymous with pollution. Beyond stressing the 12 principles of GC, the course offered a critical analysis of the role of green reagents and catalysts. Moreover, a major segment of the course presented GC as an applied science, and therefore current problems facing humanity such as recycling of plastics and vulcanized rubber, replacing chlorofluorocarbon refrigerants, and Taxol synthesis were addressed. Students wrote and presented a technological proposal on one of the assigned GC topics.

In 1999, to instill an appreciation of the value of green industrial chemistry, Cann’s [52] students made posters of award-winning Presidential Green Chemistry Challenge projects in an environmental chemistry course. The poster exhibition involved presentations and discussion.

In 2013, Manchanayakage [53] described a new GC course “Green Chemistry,” offered as an upper-level elective for science majors at a liberal arts undergraduate institution. It was a two-credit course taken over a 14-week semester that coordinated both lecture and laboratory in a workshop format so that topics were coordinated across lecture and lab. One course goal was to allow an interdisciplinary science audience to investigate, collaborate, and discuss GC from different perspectives. It was hoped that this format would spur participants to implement greener solutions for the benefit of sustainability when they become professionals. The five main sections of the course organization that heavily emphasize green organic chemistry are shown in Table 2.

In the same paper, Manchanayakage described a new liberal arts GC course “Green Chemical Concepts” for nonmajors. The course was integrated into the liberal arts curriculum. It was a four-credit course taken over a 14-week semester that encompassed separate sections of lecture and laboratory. The course brought together students from diverse nonscience backgrounds and increased their awareness of how GC contributes to sustainability. It also trained students to be science literate and enabled them to make informed decisions on science policy and business. Being designed for small classes, the delivery method was described as “interactive lecture,” employing lecture, films, and weekly discussions. From a cognitive domain standpoint, lectures targeted GC together with basic chemistry content. More specifically, the course was organized according to five main themes, namely (a) introduction, (b) ­chemical accounting, (c) chemicals and materials, (d) energy, and (e) applications, which were broken down into chemical concepts and GC concepts. In lecture, one of the key assignments was a collaborative group project on the life cycle assessment of a known green commercial product or process. Each group made a 30 min PowerPoint presentation at the end of the term. In lab, students learned both fundamental skills and science process skills. However, one novel aspect of lab was the “Atom Economy Workshop,” which was introduced to study the green synthesis of aspirin where students discussed and compared percent yield to percent atom economy. Student evaluations were reported as very positive.

In 2013, Prescott [54] described an innovative course, one of the first reported in the literature, whose purpose was to teach chemistry fundamentals from a GC ­perspective to nonmajors. The course, worth three-credit lecture, was offered as part of a novel general education curriculum designated as discovery education. The course, with only nine students, met once a week to meet the needs of the nontraditional student body who were commuters. The course followed a lecture-discussion format and made extensive use of active learning, inquiry pedagogy, and group learning, in which students used metacognition to reflect and take corrective action on their learning deficiencies. GC was integrated with chemistry content. To promote discussion, students were asked to read assigned chapters from Stanley Monahan’s online text [55] that was used as a class resource. Class discussions often followed the problem-based learning model where students are posed a question, and are then provided the information and skills required to solve it; students then work toward a collaborative solution through discussion. The problem-based learning model [56, 57] has been shown to increase both the comprehension and retention of new information. Students were assessed on both chemistry and GC content through midterm and final exams, a weekly blog entry, and a semester project that was disseminated by wiki and a public symposium. The blog increased student participation, provided starting points for the next classroom meeting, kept students connected outside the classroom, and helped students discuss and reflect on their knowledge. The final project, either individual or group, integrated general chemistry content knowledge. It was then posted on a class wiki. The course successfully covered most of the important topics studied in a traditional general chemistry course but the author identified three problems. The first problem was that it was not possible to cover all of the text chapters, presumably because of the course discussion/inquiry format. The second problem was that to promote better assessment of fundamental concepts, exams needed to be redesigned with the goal of providing more frequent feedback. The third major problem was that more frequent feedback on student blog entries would help. Students also completed the SENCER-SALG (Student assessment of learning gains) survey that measured gains in student learning. The results were positive, although the student sample was small (n = 6).

In summary, only a few valuable studies have been reported in the literature, demonstrating successfully designed GC courses. One interesting observation is that so many reports have been published demonstrating that GC motivates students to learn chemistry that perhaps a “GC Effect” is at play, combating chemophobia through bias reversal.

3.7 Organic GC Pedagogy

In this last section of Part 1 will be reviewed organic pedagogy that could be transferred to other courses. In 2007, Gaddis and Schoffstall [58] published a very well-written paper comparing and contrasting cookbook and inquiry pedagogies in undergraduate organic chemistry laboratories.

According to the authors, cookbook labs suffer from several disadvantages including that they are instructor-centered, emphasize following rote procedures in a step-by-step manner, and verify known results. The authors recommend the format of the guided inquiry laboratory because it allows student freedom without overburdening them in experimental and cognitive design.

In 2014, Graham et al. [59] published how to set up inquiry-based project labs for organic chemistry. Citing that inquiry labs more closely mimic the practice of research, the authors also noted the disadvantages of cookbook labs [60, 61]. Students worked in pairs and after picking an organic synthesis problem, they completed a literature search and designed a greener approach.

Goodwin [62] presented a “green scientific method” as a heuristic to evaluate the pedagogical and green benefits of organic labs through a risk versus reward strategy. This was done by critically examining SDS (safety data sheets) and toxicology data for reagents used and products formed, and by additionally considering the educational benefits of a lab. The evaluation process involved three steps:

1. What was green about the experiment?

2. What was not green?

3. How could the experiment be made greener?

If the educational benefits of an existing lab are low, then the nongreen lab is optimized, replaced, or eliminated. He notes that no organic reaction can ever be 100 % green, and therefore experimental optimizations can only asymptotically approach a green ideal.

The last pedagogy reviewed involves how to set up a green organic chemistry research project [63] in organic chemistry lab. Undergraduate chemistry majors transformed a nongreen organic synthesis to a greener reaction by working through published procedures in the research literature. Students worked in pairs, and they ran both the given nongreen reaction and its optimized counterpart. This guided inquiry project took place over several weeks and was successful at engaging students, allowing independence, creativity, increasing confidence, and appreciating the importance of GC. Furthermore, it helped students understand the link between academics and research.

4.1 Courses

Published papers about courses on chemistry sustainability are reviewed in this section.

Burmeister and Eilks [85] described how a novel lesson plan on plastics can be implemented and assessed in secondary school chemistry teaching as ESD, by using a sociocritical and problem-oriented approach to chemistry teaching. The authors used a Chem. Ed.-ESD model as recommended by UNESCO (2006) that

1. is embedded throughout entire chemistry curriculum and is interdisciplinary;

2. imbues the chemistry curriculum with values reflecting the goals of ESD;

3. advances and develops critical thinking and problem-solving skills required to meet the challenges of sustainable development;

4. promotes ESD utilizing educational strategic methods in debate, art, and the written word;

5. invites learners to participate in decision-making;

6. integrates ESD learning into daily and personal and professional life.

In another paper, the lesson plan employed by Eilks and Ralle [86] involved a Participatory Action Research (PAR) model in science education. PAR involves a collaboration between teachers (practice) and researchers (theory) who study science pedagogy through a cyclic process that involves designing, testing, modifying, and reflecting on research plans, resulting in novel teaching strategies and materials. The starting point involves an authentic current events’ socioscientific controversy designed to engage and motivate students to learn science content. Students then debate the issue and reflect on their learning. The five steps in PAR are summarized below. Students

1. analyze the problem;

2. perform chemical lab work to elaborate the problem;

3. apply the socioscientific dimension;

4. debate, discuss, and evaluate different viewpoints; and

5. engage in metacognitive reflection.

Experiences and feedback from teachers and students based on the cyclical development by PAR are discussed.

Karpudewan et al. [87] described a novel ESD-GC pedagogy successfully used in both high school science course, and in a methods course for pre-service teachers in Malaysia. The authors stated that their work helped integrate GC into chemistry and chemistry education curricula, and may serve as an instructional model for GC education in developing countries. However, in a broader sense it is clear that their work could be extended to any similar methods course. The authors primarily used a laboratory approach, by introducing a GC lab manual containing 27 experiments devoted to the pre-service teacher and secondary school chemistry curricula. Training and pretesting experiments were provided through workshops, in order to develop an effective and student-centered approach. Prelab questions and discussions preceded each experiment. In addition, preservice teachers learned how to convert a traditional experiment into a GC experiment. Post-lab discussions of chemistry content, GC implications, and societal/economic impacts followed each experiment. Two important sustainable concepts, natural resource accounting and life cycle analysis, were addressed, within the context of the environmental problems facing Malaysia, namely logging and pollution. In addition, students performed an experiment to produce biodiesel from palm oil, used as cooking oil, and also determined the amount of soot generated during burning and measured its heat of combustion as a lab exercise. Feedback received through surveys and assessments indicated that preservice teachers responded in a very positive way to GC principles, but found that some of the experiments could be more clearly written. For the actual secondary students involved in the study, results showed that both student motivation and content achievement significantly increased after using the GC lab curriculum. It is worthy to note that although Malaysia’s mean PISA scores (reading, mathematics, science) are in the lower third, they are introducing GC into their chemistry curricula rather than solely concentrating on chemistry content.

In another paper, Marteel-Parrish [88] wrote about the evolution of an elective GC course titled “Toward the Greening of Our Minds: Green and Sustainable Chemistry.” The course was offered to both chemistry and biology majors and minors between 2005 and 2014 at Washington College. In the course, GC instruction evolved through an iterative process. Moreover, students elaborated on their understanding of GC content by applying its tenets to real-world problems such as evaluating reaction greenness, chemical safety and sustainability, using a green decision tree, and promoting sustainability in underdeveloped countries. Students participated through daily critical discussion and writing. Student exercises involved, for example, comparing and contrasting the relative greenness of traditional commercial products and processes versus green ones. Course iterations over the years addressed these modifications and improvements:

1. GC metrics introduced included LCA, percent atom economy, and E-factor. They were applied to organic reactions such as cycloadditions, electrophilic aromatic substitution, and Suzuki coupling.

2. To promote understanding of business and green decision making, students evaluated political, societal, and business drivers in the success of GC products and processes. Students studied examples and created case studies of the successful development and implementation of green commercial processes leading to viable products. Students took into account these factors: cost to industry, the environment, health/safety, and the strengths and weaknesses of the greener product or process. Finally, students critically evaluated the outcomes of their case study using criteria in economics, production, and public image.

3. Other course modifications improved student understanding of GC in developing countries, and health and safety. Student feedback was very positive.

A novel course [89] “Green Chemistry and Sustainability” was offered for undergraduate Honors College multidisciplinary science majors and nonmajors at Creighton University. Students studied GC, surveyed the scientific literature, developed technical writing skills, and presented oral group research proposals. The novel course design was based on both environmental chemistry and the 12 principles of GC. More specifically, the three environmental themes and their GC components were as follows: (a) energy: catalysts, energy efficiency, and renewable feedstocks; (b) pollution and waste prevention: pollution, waste, atom economy, avoiding chemical derivatives, and designing for degradation and less hazardous syntheses; and (c) safety: for better products and solvents, and increased accident prevention. Students went beyond the cognitive domain and were exposed to the affective domain in which they thought critically about how chemistry can affect the Earth and its inhabitants and is linked to the sustainable earth.

Although Kovacs [90] published the next article in 2013, it addressed a novel GC course titled “Green Chemistry and Industrial Processes” that was first offered at Grand Valley State University in 2006. It was designed to bridge the gap between academia and industry by applying the principles of GC to real life through a partnership with several local businesses. The course was designed based on the results of a student designed survey of about 1,600 students of which about 70 % responded positively to wanting to learn more about GC.

Haack et al. [91] published a 2013 description of a general education science course called “Chemistry of Sustainability” that was designed and taught through faculty collaboration and team teaching. Chemistry content material supported teaching GC and sustainable issues using both a case study and problem-solving approach that utilized faculty research expertise in specific areas such as renewable energy, sustainable consumer products, bioplastics, clean water, and nanoscience. The project positively impacted everyone involved, including students and faculty team members, who developed new education materials and new perspectives. One benefit to the chemistry curriculum was that GC and sustainability were infused into more advanced undergraduate and graduate courses.

Cummings [92] provided information about “Solar Energy: A Chemistry Course on Sustainability for General Science Education and Quantitative Reasoning,” which was offered as part of the liberal arts curriculum and environmental studies minor. The course emphasized the crucial role that chemistry plays in solving energy problems by finding new and clean energy sources thereby preventing pollution. The course addressed the problems caused by fossil fuel combustion and then explored clean alternatives such as solar energy, including solar radiation, combustion, greenhouse gases, ethanol, photovoltaics, water electrolysis, fuel cells, hydrogen storage, and batteries. In order to understand the chemistry associated with fossil fuels and solar energy, content chemistry in the following areas was taught: reaction stoichiometry, molecular structure, thermochemistry, catalysis, energy quantization, and electrochemistry. Students utilized critical thinking skills and quantitative reasoning. Moreover, the liberal arts nature of the course fostered interdisciplinary connections with economics, politics, ecology, and human health. Students were assessed on their participation in discussions, lab assignments, and performance on pre- and posttests on these areas: solar energy policy, applied solar energy, and solar energy. Students showed significant gains. Moreover, students rated the course with good reviews.

Brinkert et al. [93] cited the United Nations Rio Declaration on Environment and Development to justify a graduate-level course on solar energy and sustainable development open to students from both nonscience and science backgrounds. The course may serve as a model utilizing novel content and pedagogy for other academics to introduce a similar course on sustainability into other chemistry programs. The title of the course “Perspectives on Solar Energy from Science, Industry and Policy” was a collaborative effort combined with the Center for Sustainable Development and the Department of Chemistry, Ångstrom Laboratories, at the Uppsala University, Sweden, in spring 2012. One goal was to design and implement a cross-disciplinary university course to train both academic and nonacademics from a variety of backgrounds, including nonscientists, to meet the growing demands of ESD across the university curriculum. Everyone, including nonacademics, could apply to participate in the course even though they lacked background knowledge on science and solar energy. The selected student cohort represented three distinct groups: social science, natural science, and solar energy professionals who were trained in natural science.

The course provided a general review of solar energy through the balanced views of science, policy making, and industry. It was further organized around these components delivered as modules: politics, humanitarian, industrial, and solar energy. The 3-week course was limited to 16 participants who were selected based on their different educational backgrounds, cultural diversity, and motivation. The course was deployed in a format involving lecture followed by in-depth discussion; it also utilized guest lecturers. Students then completed additional assignments such as labs. Before each assignment, students prepared short assignments that complemented their research background.

A course named “Organic Synthesis Techniques” was described by Dicks and Batey [94], which was an advanced organic lecture-lab course whose main goal was to introduce green and sustainable chemistry principles to undergraduates through the study of catalytic methods. New experiments were designed to investigate these catalytic methods: phase-transfer catalysis, organocatalysis, Lewis and Brønsted acid catalysis, and transition metal catalysis. In lectures, students studied the principles of GC, and compared and contrasted catalyzed syntheses to traditional ones through industrial case studies. In addition to catalysts, in lab, students also investigated these types of reaction solvents: solvent free, water, greener organic solvents, ionic liquids, and supercritical CO₂.

4.2 Other Papers

Fisher’s paper [95] published in 2012 supports the idea of including the global issue of sustainability as part of a professional curriculum reform in chemistry because it provides a richer context and more well-rounded liberal arts educational experience, meets the United Nations declaration calling for a decade of sustainable development, and last of all, meets an ACS guideline that chemistry majors should be aware of the role of chemistry in contemporary societal and global issues. Moreover, according to Sherman [96], the focus of ESD in higher education should address these areas of (a) determining prescribed practices; (b) campus operations; and (c) instituting new academic programs.

Through a “perspective,” Burmeister et al. [97] described how chemistry education can incorporate the UN’s DESD plans into their educational programs. The article began by justifying ESD across the three domains ecology, economics and society. The authors recognized the important role that GCE played in sustainability and cited many examples, such as the ozone hole problem, that can be used as pedagogical case studies that lead to positive changes in student knowledge and understanding. They suggested four basic pedagogical models ranging from narrow to wide involvement with regard to their respective academic communities. These models that can be combined and have the capacity to infuse sustainable development into formalized chemistry education curricula are given in Table 4. The authors believed that models 3 and 4 have the most potential for successfully integrating ESD with chemical education because students will learn about and learn to contribute to sustainable development. However, all four ESD proposed models require much more than modifications to curricula, but instead require redirection and redesigning curricula across interdisciplinary science fields, and extending them to include society, economics, and ecosystems.

A Finnish article [101] offers an in-depth review of the status of ESD in chemistry (ESD-Chem) by analyzing current models for their relative strengths and weaknesses, and offering three distinct pedagogical models for future practice in Finland. Although the goals of ESD-Chem are straightforward, namely empowering citizens, consumers, and educators to act on the levels of the individual, the community, and the ecosystem for a sustainable world, implementing it in the classroom is a very complicated enterprise. The complications relate to more than integrating the concepts of sustainability and GC and arise when incorporating SSI into the classroom. Therefore, this Finnish model may not be a viable pedagogy for US secondary schools that are focusing on attempting to overcome chemistry content deficiencies, whereas Finnish PISA scores are in the top tier. After analyzing current models of ESD-Chem pedagogy, they propose these new models:

1. A holistic ESD-basic chemistry pedagogy offers these attributes: interdisciplinary, student centered, inquiry based, with social interaction to promote socioscientific argumentation practices by examining SSIs and societal cooperation with stakeholders.

2. The second model’s dominant characteristic shows the teacher how to implement a student-centered strategy.

3. In the third model, a three-phase strategy implements SSI instruction through empowering students.

Overton and Randle [102] published a 2015 paper related to teaching sustainable chemistry to first year chemistry undergraduates. One purpose of the course was to train chemistry students in sustainable development before they enter industrial careers. In particular, students used dynamic problem-based learning, a constructivist approach, to solve real-world problems such as designing sustainable residential villages subject to a variety of constraints such as cost, environmental impact, and trading partly limited to the local economy. Another interesting problem was deciding whether biodiesel or bioethanol was more cost effective as a fuel for a fleet of 42 buses. Students presented written and oral group reports.