From linear to circular: tackling plastic waste in scientific labs
Strategies to solve the problem of over 5.5 million tonnes of annual plastic waste from scientific institutions
While much attention has been drawn into reducing single-use plastics in our everyday consumables, endeavours to reduce plastics in scientific labs have only recently attracted attention.
In 2015, a study by the University of Exeter estimated that approximately 5.5 million tons of plastic waste were generated in scientific labs worldwide. This corresponds approximately to the combined tonnage of 67 cruise liners or roughly the double amount of plastic waste generated by number one corporate polluter Coca Cola . The researchers based their estimate on extrapolations from their own plastic use. More accurate statistics for global single-use plastic by scientific institutions do not seem to be available. However, looking at the reported amounts of plastic waste by scientists worldwide during the #LabWasteDay social media campaign, numbers could be even higher.
It becomes evident that depending on the research topic and lab practises, annual plastic waste may range from ~ 60 to 1,600 kg per scientist.
The amount of single-use plastics has further increased during the Covid-19 pandemic,. Not only has the increase in plastic waste been driven by personal protective equipment (PPE) such as masks and gloves, but also by pipette tips, plates and test tubes used for Covid-19 testing. In fact, the increasing demand for testing, has resulted in chemical and pipette tip shortage in many parts of the world.
Single-use plastics such as gloves, pipette tips, cell culture dishes and tubes have become indispensable in the lab since they are cheaper and often more convenient than glassware. Plastic is lighter than glass and more resistant to breakage or certain chemicals. In addition, most plastics in the lab have to be single-use in order to avoid contamination of samples with other reagents, bacteria or organisms. The problem, however, is that most plastics cannot be recycled due to contamination with biohazardous materials like blood or genetically modified organisms. This type of waste is often incinerated or, autoclaved and sent to landfill. Other plastics that are not contaminated (e.g. test tubes with water or aqueous salt solutions) are still classified as “lab waste” since most recycling plants do not accept these due to health and safety reasons and are sent to landfill ,,.
Implementing a more circular economy in scientific labs
Certainly, reducing, reusing and recycling may be a challenging concept in many scientific labs, but it is not impossible.
How to reduce and reuse plastics in scientific labs?
Depending on the experimental area and sterility requirements, it is possible to reduce and reuse plastics to a certain extend through careful planning and cleaning without compromising the experimental outcome. For example, some experimental set-ups allow to reuse pipette tips. Gloves can be cleaned with ethanol and worn a few times. Weigh boats can be reused when cleaned properly between uses. Plastic tubes containing aqueous buffers can be rinsed and reused etc. Further, plastic waste from consumable packaging can be reduced by ordering in bulk, thereby reducing the number of deliveries.
Especially in scientific labs that do not work with biohazardous material or have strict sterility requirements, it is worth to look into reusing plastics through cleaning. Alternatively, some plastics can be replaced with glassware. Glassware and some plastics can be washed and sterilized using steam (autoclave) and thereby be reused. It is important to know which plastics can be used for cleaning in autoclaves since plastics like polystyrene (PS), polyethylene (PE), and high-density polyethylene (HDPE) cannot undergo this process and are thus generally discarded to waste. The company Grenova Solutions has developed a special washing machine to wash and also sterilize contaminated pipette tips in large quantities for reuse. Through this technology, the company estimates to have reduced approximately 570 tonnes of plastic waste since 2015.
Reusing does reduce plastic waste, however, one important aspect that has to be pointed out is that reusable solutions require a high amount of energy and water as well.
How to encourage and increase recycling incentives in scientific labs?
There are two main issues when it comes to recycling of plastics in scientific labs.
The first one is that many plastic products are a mix of plastics and therefore cannot be recycled. Secondly, contaminated plastics with biohazard materials are usually not allowed to be recycled due to health and safety reasons.
The first issue can be solved by purchasing lab consumables in a more sustainable way by replacing mixed plastic products with recyclable plastics. Most suppliers readily supply this information upon request or on their websites. Alternatively, My Green Lab has developed an environmental impact factor label called ACT that helps scientists to understand the impact of lab consumables, chemicals and equipment. By evaluating manufacturing, energy and water use, packaging, and recycling, lab products are given a score and the lower the score, the lower the impact on the environment. This may be a useful resource to compare products and make more informed decisions about products.
There are a few schemes available that allow recycling of non-contaminated lab plastic waste. For example, RightCycle by Kimberly-Clark Professional recycle nitrile gloves and other PPE if returned. However, only gloves by Kimberly-Clark Professional and used in non-hazardous research are accepted in the return scheme. StarLab pipette tip boxes can be reused by the company if returned and can withstand up to 100 autoclave cycles before being recycled. Polystyrene boxes used to ship items are taken back and reused by New England Biolabs, but according to their website (date from Sept. 2019) only 28% of boxes are returned by customers in the UK for reuse.
The University of York has developed a simple and cost-effective decontamination process for contaminated plastics, which consist of soaking them for 24 hours in a high-level disinfectant and a consequent rinse with water. The inventors of this procedure state that contaminated plastics cleaned this way could be potentially safe enough for recycling purposes. Overall, it seems to be a promising approach to solve the contaminated plastic issue and reduce the amount of plastics ending in landfill.
Moving forward: The necessity of rethinking labware design
Plastic waste can further significantly be reduced through improving the design of single-use plastics by cutting down on material and packaging by producers.
Since single-use plastics cannot be completely excluded in all areas of research like in cell culture experiments, labware companies should consider to redesign products using less plastic. Some companies have already started to do so. For example, the company StarLab now manufactures their TipOne pipette tips with up to 40% less polypropylene. LabCon, a Californian company, offer several more sustainable solutions. The company avoids co-molded plastic blends that are generally more difficult to recycle. They also attempt to reduce packaging and offer bioplastic products. New England BioLabs re-designed columns using less plastic and packaging boxes suitable for recycling.
As outlined in this article, there is an increasing interest and proposals on how to cut down on plastic waste in labs. The University of Leeds and University College London aim to eliminate single-use plastics by 2023 and 2024, respectively and hopefully more scientific institutions will follow.
Being a scientist myself, I believe it is a scientist´s responsibility to understand the environmental impact our research has and to find solutions to the plastic wate problem. Implementing some of the suggestions highlighted in the article will make a significant difference and the more we can spread awareness about this topic, change is likely to happen.
Solving the plastic waste problem in scientific labs is only a first step. There is a lot of work that must be done to improve the sustainability in lab procedures.
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 Urbina M A, Watts A J R and Reardon EE 2015 Nature 528 479