In the last article featuring the University of Arizona’s milli-scale approach, GREEN was given a chance to see the project in action. Students were performing experiments on a smaller scale than what is traditionally seen in a teaching laboratory and the impact has been noticeable. What had been believed to be a 1/3 and 1/5 reduction in aqueous waste for the first and second semester of general chemistry is actually a 2/3 and 4/5 reduction. In other words the milli-scale approach has cut out 60% of aqueous waste for one semester and 80% for the next. With waste reduction on this scale, it is no surprise that by the end of the 2014-2015 academic year the overwhelming majority of chemistry teaching laboratories will have incorporated the milli-scale approach.
Changing fifty laboratory sections to this new approach will not be a simple task. However, the team here at the University of Arizona is not only setting these new labs up, they continue to look for ways to make procedures “greener”. The integration of milli-scale means that many large waste-producing labs from the macro-scale past will be replaced. There are also some labs that are being redesigned. One example is a lab where students are asked to create paint and test its properties. With the milli-scale approach, students produce smaller amounts of pigments for their paint, which reduces the amount of waste generated. In addition, students can combine their pigments with biodegradable polymers of varying molecular weights. Other experiments, such as the synthesis of an indigo dye, have been replaced with an experiment where students analyze the food dyes of candies.
With some changes, students are also gaining insight into very important applications. Students in the new teaching labs will not only synthesize an important medication like aspirin but they will also be challenged to find shelf life of a liquid sample containing aspirin. Most importantly, every experiment done with the milli-scale approach has students thinking about the amount of chemicals they use. With small quantities they must be mindful not waste anything they use.
Another aspect that has been stressed about the milli-scale approach is safety. With smaller quantities of chemicals comes a smaller chance for something to go wrong. This has been very apparent, as there have been zero incidents of chemical exposure in the first semester milli-scale labs. Currently the laboratory staff is creating safety procedures that will also be integrated into the organic chemistry courses. Safety is definitely an important part of any introductory laboratory; many students entering these courses do not know proper laboratory safety procedures. By introducing these procedures early, and having them be present in later courses, reduces the chance of there being an accident.
The milli-scale approach is very much about students creating hypotheses, carrying out a number of smaller scale experiments, and using trends to predict outcomes. Milli-scale students achieve the same learning goals and perform similar experiments as their macro-scale counterparts but they do so by generating less waste. However, even with a shift to more milli-scale labs there can still be some improvement to the project. For this reason the staff working on the milli-scale approach continue to find ways to improve. New and older experiments are constantly scrutinized in hopes of finding ways to make them greener. The group is even looking at publishing some of their analytical techniques using LED lights. Exploration is also being made into the specialized general chemistry section for nursing students to make them greener and to better tailor that lab to nursing students. It has been exciting to see the success of this project and invigorating to know the teaching labs will continue to become “greener”.
I would like to thank Mark Yanagihashi for his continued insight into this project and the great amount of information he has provided.