By Savannah Marshall

Every laboratory researcher produces nearly 15 times the amount of plastic waste as the average individual.¹ The sturdiness of plastic that makes it so desirable for use in laboratories creates a large problem when it comes to disposal. A plastic bottle takes about 450 years to decompose, and it leeches toxins into the environment in the process.² The deep-seeded dependence on plastic in research can make change seem daunting. However, we cannot let our reliance on plastic  stop us from making the small stepwise changes necessary for independence from this scourge of the environment.

I am sure we all are familiar with the 3 Rs; Reduce, Reuse, and Recycle. However, did you know that these actions are in this order for a reason? Reducing waste is the first and most important step to environmental sustainability, and recycling is the last resort for waste we produce. In fact, only 9% of all plastic produced has ever been recycled.² Even when individuals do their part to responsibly separate their waste for recycling, it often ends up in the landfill anyway. For this reason, reducing plastic consumption is the most important step, and reusing plastic is the next step for keeping it out of landfills. Recycling plastic should only be done for non-reusable products. I will outline many tips here for the best ways to implement the 3Rs in your lab.

Reduce

While most of the responsibility lies with manufacturers and institutions to reduce reliance on plastic, we cannot ignore our individual role in plastic consumption. We generally plan experiments as efficiently as we can, but we should also consider designing experiments to minimize the use of consumables where possible.³ Being cognizant of your pipettes ‘order of operations’ can help in reducing tip use. Say you are preparing 12 samples in which you add sterile water, sample buffer, and protein. If you add water to all tubes, then sample buffer, then the protein, you can use only one tip for the water and sample buffer steps, then switching tips for adding the protein, for a total of 13 tips. If you add protein first, you need a total of 36 tips, so you do not contaminate the water or sample buffer. Additionally, aim to use the smallest tubes possible for the volume you are using. It can waste material aliquoting 50uL into 1.5mL tubes when most labs have 500uL tubes.⁴ Smaller tubes also take up less freezer space and thus reduce clutter resulting in the freezer door being open for less time.² These practices can reduce the amount of plastic consumed, but there are also procedures where we can completely avoid using plastic altogether.

We generally use plastics for sterile applications, but not everything we do needs to be sterile. If you are making a media solution that will be sterile filtered, you do not need to use single-use sterile plastics for preparing all ingredients.² I am sure many of us are guilty of using sterile plastic pipettes for measuring milk for a western blot when a glass graduated cylinder is the environmentally responsible choice.⁵ Reusable and autoclavable glass can replace plastic usage, and the initial investment will end up paying for itself in just a few uses. In fact, even single-use glass is better than single use plastic. Unlike glass, plastic is not endlessly recyclable. Recycling plastic is actually ‘downcycling’ as it becomes a lesser quality product each time.⁶ Autoclavable glass is generally the best option for many applications, assuming your lab has the ability to decontaminate glass.^3,7

An often-ignored aspect of lab plastic use is packaging plastic, mainly comprised of stretchy types of plastics called plastic film. Although plastic films from packaging are not a biohazard, institutions rarely have waste streams for handling this type of plastic. This is because plastic films clog normal recycling machinery and need to be handled separately; in other words, the plastic films are expensive to recycle. The bright side is that this plastic can be recycled for free when taken to plastic film drop-off locations. However, remember that recycling is the last resort, and reducing packaging plastic is the first step. To reduce consumption of packaging plastic, order reagents and chemicals in bulk and make sure to consolidate shipments with other lab members. This also helps cut down other environmental costs of shipping such as greenhouse gas emissions. Most importantly, take advantage of bulk ordering by buying from your on-campus supply center, such as the one at Penn State College of Medicine, for any common reagents they supply.

Reuse

Most plastics we use in labs are made from high quality high-density polyethylene (HDPE), which is made to withstand high temperatures and harsh chemicals.² So why toss it away like a day-old salad? Here are some recommendations for ways to reuse plastics in lab:

• Reuse non-contaminated gloves
• Reuse weigh boats
  • I put a labelled weigh boat on the containers of things we measure frequently, such as milk
• Use empty bottles and containers for something new
  • So many things can be used for holding western blots
  • Make buffers in empty media bottles
• Clean and reuse conical tubes. Also, make sure to look out for take-back programs from vendors such as the Polystyrene Cooler Return Program from Sigma.

Recycle

Unfortunately, it’s very difficult to recycle lab plastics. Even if plastics are responsibly separated by lab members, or responsibly sterilized, many recycling plants may still reject it due to uncertainty of contamination.² This is a shame considering most lab plastics are made of a highly demanded material. While programs for recycling gloves and other lab plastics are becoming more popular, the best option will always be to reduce the consumption of these products in the first place. The best option for recycling plastics in labs is carefully rinsing non-hazardous plastics (media bottles etc.) and recycling them according to the institution’s guidelines when possible. Also make sure to take advantage of any other recycling opportunities your institution offers such as the pen/marker recycling offered through Terracycle at Penn State College of Medicine! Some suppliers are also beginning their own recycling programs for some materials, such as Corning.

Conclusion

Labs are estimated to trash 5.5 million tons of plastic waste in a single year; that is the weight of 67 cruise liners!¹ Only 0.1% of people are in a scientific role, yet scientists contribute ~2% of plastic waste worldwide.⁸ Scientists are educators and should do their part to improve awareness and take responsibility for their role in the plastic crisis. Science can no longer justify environmentally detrimental plastic use by the cost and time saved, leaving labs among the last to join the sustainability movement. Start saying NO to single use plastics and educating your peers on the impact of laboratory work on the environment.

TL:DR

Researchers need to do their part to reduce plastic waste by ordering and designing experiments thoughtfully, using glass alternatives, and finding creative ways to reuse plastics.

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1.         Urbina, M. A., Watts, A. J. R. & Reardon, E. E. Labs should cut plastic waste too. Nature 528, 479–479 (2015).

2.         My Green Lab. MGL Waste Module.

3.         Kuntin, D. How to… reduce your lab’s plastic waste. RSB https://www.rsb.org.uk//biologist-features/how-to-reduce-your-lab-s-plastic-waste.

4.         Howes, L. Can laboratories move away from single-use plastic? Chemical & Engineering News vol. 97 (2019).

5.         How to use plastic more sustainably in the lab. Radleys https://www.radleys.com/blog/how-to-use-plastic-more-sustainably-in-the-lab/ (2020).

6.         Kellogg, A. K. Which is Better For The Environment? Glass or Plastic? Going Zero Waste https://www.goingzerowaste.com/blog/which-is-better-for-the-environment-glass-or-plastic/ (2019).

7.         Bistulfi, G. Reduce, reuse and recycle lab waste. Nature 502, 170–170 (2013).

8.         Krause, M., Gautam, K., Gazda, M. A. & April 2020, A. N. Reducing plastic waste in the lab. Chemistry World https://www.chemistryworld.com/opinion/reducing-plastic-waste-in-the-lab/4011550.article.