Elicia Preston, research scientist and lab manager in the Genetics department at the Perelman School of Medicine/University of Pennsylvania, took action to reduce plastic waste in the laboratory by switching to glass petri plates. Data shared by the University of Cambridge Sustainable Labs and generated by the University of Edinburgh, based on usage and conversion factors sourced through the UK Department of Business, Energy & Industrial Strategy, reported that labs produce plastic waste representing 2000 times the emissions of lab glass waste. Using glass prevents pollution by generating 3.6 times less CO2 than plastic.
What is the focus of your lab group’s research?
Our lab studies developmental genetics with a focus on single-cell RNA-sequencing and time-lapse imaging of C.elegans embryos.
How did you become interested in laboratory sustainability?
Labs use huge amounts of energy and produce megatons of waste. As a biologist, my fascination with the complex beauty of nature coupled with the irony of trampling nature, to better understand it, frustrates me. So I do what I can to lessen this negative impact of our work.
You started the glass petri plate pilot study in 2015, before most scientists were thinking about the volume of lab plastic they used. What was the final outcome of that project?
Our lab, like many, consumes hundreds to thousands of petri dishes per month, and therefore a switch to reusable glass petri dishes has saved tons of energy and landfill space. One pound of polystyrene petri dishes costs 11.28 kWh of energy, 20.54 gal. of water, creates 0.113 lb. of solid waste and emits 2.51 lb. of CO2 (worldcentric.org/sustainability/energy-savings). On top of all this, there is the energy and CO2 emissions involved in shipping all of the polystyrene petri dishes to the labs and then removing them for disposal. Finally, there is the cost of megatons of landfill space. Fossil fuel combustion from industry, including plastic-manufacturing, accounts for 14 per cent of total U.S. CO2 emissions (www.epa.gov/climatechange/ghgemissions/gases/co2.html). More specifically, UPenn researchers purchase 400,000 disposable petri dishes per year. This petri dish waste, if lined up, would fill the length of the state of Pennsylvania. In contrast, glass culture dishes are only manufactured and shipped once, and would only enter landfills when broken.
Once the glass petri dishes were in place, did they require more time to use?
It is definitely more work to use them for my autoclave worker and myself, but not for my labmates. The agar has to be removed, then I soak them in bleach-water overnight, then I wipe the writing off of them and dry them, then my autoclave worker has to wash them and then autoclave them.
What series of steps was involved in setting up the glass petri dish pilot?
I brooded over all the waste in my lab for years. Then I brought up using reusable glass petri dishes to my boss, who expected that it would be a lot of extra cost and labour. However, a lab mate and the autoclave worker promised that they would support me, so I applied to a Green Fund grant through the university’s sustainability department, which I won. I used that grant to purchase our lab’s glass petri dishes and a petri dish rack for the dishes to be washed in the glassware washer. Then I had to figure out the pipeline for the cycling of petri dishes and overcome some biases against using glass, like that they would be less sterile (they are not). Good communication with everyone in the lab was important, as well as getting the department business office in the loop. Now we are cycling through pretty efficiently and our lab is using almost half glass and half plastic.
What factors should scientists consider when switching to glass petri dishes?
Remember that you are always going to have those times when you are waiting for something like an incubation or a centrifuge step. It sounds like a lot of work but it is really easy to integrate this into your week. It is going to be a lot smoother in terms of workload if your building/ department has a dedicated dishwasher/autoclave worker.
Would you say that any research lab growing bacterial cultures on petri plates could switch to glass?
Yes, definitely. Even if they do half and half, it will make a difference. It is just as sterile, and your lab will save money in the long-term.
Do you have any other helpful tips?
I have also started processing the plastic petri dishes similarly for recycling, although I have ambiguous feelings about the way recycling is done, with all the shipping and fossil fuels involved. So if you can’t manage to do glass, I would encourage labs to at least buy biodegradable petri dishes or process your petris for recycling. If you are seriously considering using glass, please feel free to contact me at: firstname.lastname@example.org.