SUSTAINABILITY
We Need to Talk About Plastic Lab Waste
Single-use plastics are ubiquitous in labs — but is there anything that can be done about it?
Monica Ohnsorg considers herself to be an environmentally conscious person. She takes public transit, reuses plastic containers, carefully sorts her recyclables, and tries to teach others how to recycle more effectively using the number codes stamped into plastics.
At work, however, it’s a different story. Ohnsorg is a Chemistry Ph.D. student at the University of Minnesota researching materials to help drugs absorb into the body. A series of experiments she did this past winter to measure the amount of drug in simulated intestinal fluid generated ten gallons of waste over the course of two months — gloves, syringes, filters, and more. Most of the waste is plastic. All of it is essential to her work. None of it is recyclable because it’s contaminated with the drug she’s measuring. “It’s a really big issue, but I don’t know if I have an idea of how to get around it at this point,” she says.
Calling it a big issue is an understatement: Scientists at the University of Exeter estimated in 2015 that research labs worldwide produce somewhere around 5.5 million metric tons of plastic waste per year. That’s about twice the total amount of plastic recycled in the United States in 2017, according to the Environmental Protection Agency. Recognizing the urgency of concerns about climate change and pollution, many research institutions are initiating recycling programs for certain types of plastic lab waste and other hard-to-recycle materials. However, achieving true sustainability for lab waste will require more comprehensive solutions than adding a few recycling bins.
Want to read more about sustainability in science? Check out this piece from Lab Manager on how academic lab sustainability initiatives are working to increase participation on university campuses.
It’s Not Easy Being Green
Even at home, recycling is easier said than done. Each number code represents a different type of plastic with a different molecular structure. Melting plastics with different structures together during a typical recycling process gives a material that’s functionally useless — and that doesn’t even consider the effects of additives like dyes. For conventional plastic to be recycled effectively, it has to be as clean as possible and each type of plastic must be separated from the others. “You can’t just throw anything in the single sort — it’s only single sort for two plastics, and glass and paper,” says Ohnsorg. “(Recycling numbers) one and two can be recycled, and maybe five but probably not.” Nick Ciancio, the Green Labs coordinator at the University of Alabama at Birmingham, has established recycling streams for pipet tip boxes (usually #5), ice packs, foam coolers (#6), glass, x-ray film, and gloves — as long as they are clean.
Lab-centric recycling programs for a given plastic item are typically facilitated by a company that supplies that item to labs. Fisher Scientific, for example, sells plastic pipet tips as well as special waste boxes for the empty plastic containers that the tips come in, which come with shipping labels to mail the box to a facility that specializes in recycling hard-to-recycle varieties of plastic. By partnering with Fisher, the University of Michigan has saved half a million pounds of plastic pipet tips from going to a landfill over the past ten years according to Ken Keeler, Senior Sustainability Rep at the Michigan Office of Campus Sustainability. “They all go to this one guy in Toledo who makes park benches out of them,” he says. The recycled material is nowhere near as high-quality as the original, but at least it’s not going to the dump or the incinerator.
The kinds of contaminants found in labs can be fairly hazardous, especially in labs devoted to biological research, which often involves bacteria like E. coli. Waste contaminated with biohazardous material can be recycled in theory, Ciancio says, but it would have to be sterilized first, and the energy and water cost of sterilization may outweigh the benefit of recycling. A single autoclave (the steam chamber used for sterilizing equipment in bioscience and medical labs) can consume upwards of a million gallons of water per year according to Consteril, a leading manufacturer of sterile supplies.
Thinking Outside the Recycling Bin
Given the difficulty of recycling, the other two Rs — reduce and reuse — are just as if not more important for scientists to keep in mind if they want to minimize the waste they send to landfill. Glass can be washed and reused many times over, although Ohnsorg says many people she knows are wary of growing cells in glass Petri dishes that have been previously used, even if they have been autoclaved first. Jovan Kamcev, an Assistant Professor of Chemical Engineering at Michigan who researches polymers for water treatment, says his lab can’t use glass containers for some experiments because ions in the glass leach into the water and interfere with measurements, but they do try to reuse their plastic jars whenever possible. Sometimes it’s not feasible to reuse things, like when a reaction is being performed with potentially harmful chemicals. “You don’t want to be reusing things if you spill solvent on your gloves,” says Kamcev. In that case, the gloves probably aren’t recyclable either.
Single-use plastic doesn’t seem likely to disappear from daily life, in or out of labs, any time soon. Still, Ohnsorg is cautiously optimistic that someday research will discover a way to make sustainable alternatives with the right properties to replace the conventional plastics in her lab waste. “We can make sustainable adhesives that are on par with duct tape,” she says, “so there might be hope to create a sustainable material that has solvent resistance — it’s a waiting game to figure out who figures it out.”
Brianna Barbu is a science writer and green chemistry enthusiast from Michigan. You can find links to more of her work at bri-barbu.com.
