Just Shut It!

By James LaFortune and Shawn Postle, Members-at-large for the GCI

The Green Chemistry Initiative (GCI) and the University of Toronto constantly strive to reduce the environmental impact inherent to research in the Chemistry Department.  A major contributor to the department’s carbon footprint is its fume hoods, which are required to safely carry out experimentation with volatile solvents or reagents.  They provide a partially enclosed working space that draws air from the laboratory into the hood, thereby reducing the researcher’s exposure to chemicals. However, this requires replacing the removed air with acclimatized outside air, a process which consumes large amounts of energy in heating or cooling the air.

Fume hoods are designed with a height-adjustable glass pane (sash) that allows the researcher to work while keeping the space as enclosed as possible. There are two main types of fume hoods used in chemistry labs: constant air volume (CAV) and variable air volume (VAV).  With CAV, the air flow remains constant regardless of sash height, while VAV systems are designed to moderate air flow based on the sash height.  Each fume hood requires roughly as much energy as three American households when in use.  However, roughly 50% of this energy can be conserved in VAV systems if the sash is kept shut.  Given that the Chemistry Department has 123 VAV fume hoods, ensuring that VAV sash heights are minimized during idle periods is an effective strategy to reduce unnecessary energy consumption.1


The GCI’s Just Shut It! Campaign, renewed this past summer for its third season since 2008, encourages graduate students to close VAV fume hood sashes during idle times and to minimize sash height when working in the hood.  Fume hoods are checked weekly by GCI volunteers to ensure compliance and users of fume hoods found to be in compliance are entered into monthly prize draws.  The past two Just Shut It! Campaigns (read more about the original campaign) were very successful, where compliance rates increased from 3% to 61% during the campaign. Since its reinvigoration over the summer, we have recorded similar compliance levels as previous campaigns.

What’s more, the Chemistry Department currently only uses VAV fume hoods in its Davenport wing.  However, it is exploring air systems renovations, including replacing CAV with VAV fume hoods in much of the Lash Miller wing.  These additional VAV fume hoods will further decrease our environmental impact.

This time around, we are looking to keep the Just Shut It! Campaign going permanently.  Gracious thanks to the Department of Chemistry for funding this campaign, especially Chief Administrative Officer Mike Dymarski.

  1. E. Feder, J. Robinson and S. Wakefield, International Journal of Sustainability in Higher Education, 2012, 13, 338-353.

Developing Green Chemistry Content for First-Year Undergraduate Laboratories

By Shawn Postle, Member-at-Large for the GCI

The Chemistry Teaching Fellows Program (CTFP) at the University of Toronto gives senior graduate students the opportunity to gain pedagogical experience by developing new educational content for undergraduate students within the chemistry department.

I recently had the opportunity to complete a CTFP project in collaboration with Dr. Barb Morra where we designed a new laboratory experiment for CHM 151Y, a first year organic chemistry course. The experiment that we aimed to replace involved the concurrent hydrogenation/dehydrogenation of cyclohexene using a palladium catalyst, to form cyclohexane and benzene. There were two main concerns with this experiment: the use and generation of carcinogenic and toxic chemicals, and the efficacy of a simple demonstration of alkene reactivity due to the lack of qualitative observations that could be made to differentiate the products from the starting material.

To address the shortcomings of the old experiment, we had three goals in mind while designing the replacement experiment: 1) to reinforce concepts of alkene chemistry learned in lecture, 2) to emphasize the importance of sustainable chemistry, and 3) to introduce thin-layer chromatography.

The L-proline catalyzed cyclization of L-linalool was an ideal reaction for satisfying these three criteria. In the lecture component of the course, students learn about electrophilic addition reactions of alkenes, such as halohydrin formation (Scheme 1a). For the experiment, we chose an intramolecular variation to show this same type of reactivity. The reaction carried out in the lab is the cycloetherification of L-linalool (Scheme 1b).

Green chemistry for alkene reactivity

Scheme 1: a) Halohydrin formation, b) Cycloetherification of L-Linalool

Students also perform thin-layer chromatography to verify that all of their starting material has been consumed. Thin-layer chromatography is an ideal technique for first year students, as it is a relatively simple method of analysis to understand and carry out.

In this new experiment, students are introduced to the 12 principles of green chemistry. We draw their attention to specific examples from the reaction to illustrate different principles. L-linalool, a terpene alcohol, is derived from renewable resources (principle #7). The reaction is catalyzed by innocuous L-proline, which reduces the reaction time from two days to a few minutes (principle #9). N-bromosuccinimide (NBS) is a safer alternative to elemental bromine as a source of electrophilic bromine (principle #4). Moreover, students are directed to the GlaxoSmithKline safer solvent guide to compare the properties and environmental impact of the solvent used to those employed in older cycloetherification reactions (principle #5). This gives students insight into how the 12 principles of green chemistry can be effectively applied with just a simple substitution.

Some of the 12 principles of green chemistry are fundamentally easy to understand, even for a first year student, but others require more chemistry background. It is through repeated exposure to these ideas that students can gain a fuller appreciation of their importance. Introducing students to the concept of sustainable chemistry throughout their chemistry education in a variety of courses helps students understand that green chemistry is not something separate from organic, inorganic, analytical or any other type of chemistry, but is rather a philosophy that can always be implemented.