The Hidden Cost of Science: Unpacking the emissions of laboratory plastics

Guest blogger Isabella Ragazzi, Research Associate in Life Cycle Assessments and Carbon Footprinting at UCL, writes about the impact of plastic in the lab.

Science research is often hailed as a force for positive change, responsible for incredible breakthroughs in medicine and our deepening understanding of the natural world and the human condition. However, these advances have not come without a price. In recent years, scientists have been raising alarm bells regarding the high resource consumption and carbon emissions associated with research, especially in laboratory settings. While many laboratories have begun to make changes to reduce energy-intensive lab equipment usage and identify more efficient products to lower their carbon footprints, one critical issue has largely flown under the radar: the environmental impact of lab consumables, particularly single-use plastics and protective wear.

The reliance on single-use plastics and protective gear has increased in recent years, intensified by the global pandemic, which witnessed a significant uptick in the use and disposal of gloves and masks. One estimate suggests that biological, medical, or agricultural research alone generates a staggering 5.5 million tonnes of plastic waste annually, equivalent to the carbon footprint of over a million UK citizens.

While scientists acknowledge this heavy reliance on plastic waste as a problem, accurately estimating the emissions associated with these products has proven to be challenging. At the University College London (UCL), our team sought to tackle this challenge by using the findings of Life Cycle Assessments (LCAs) of similar plastic products.

Life Cycle Assessments (LCAs) are studies that scrutinise a product's lifecycle—from raw material extraction and manufacturing to transportation, consumer use, and disposal. Boundaries can differ, but typical ‘life cycle’ boundaries for a plastic product are shown in the figure below.  LCAs provide detailed insights into the stages responsible for the highest greenhouse gas emissions and allow for comparisons between different product manufacturers.

After combing through dozens of LCAs, our team compiled a list of emission factors for lab products, either directly based on the product or using analogous products as proxies. Our findings, detailed in our published study, shed light on the carbon footprint of these items, revealing that emissions for plastics and protective lab wear are primarily concentrated in three key areas: the production of plastic polymers, incineration, and product manufacture. Packaging and transport-related emissions for these products were relatively low, comprising less than 10% of the total emissions.

Our research yielded several key takeaways

1. Within the lab, responsible disposal can reduce carbon impacts.

In the lab, changing how plastics are disposed of can have substantial benefits. Incineration generates over half of the emissions of protective wear and plastics. Opting for recycling instead of incineration for recyclable plastic products, such as those made of polypropylene, polycarbonate, and PET, can cut overall emissions by 50-74%, depending on the type of plastic.  However, recycling is not possible for common consumables such as nitrile gloves, polystyrene products, or personal protective wear. In these cases, reductions in use and substitution with alternative materials is needed.

The good news is that alternatives exist for many plastics. Sometimes, the same lab product can vary in terms of the plastic material they are made of depending on the brand. For example, deep-well plates can be made of polypropylene or polystyrene. Choosing deep-well plates made of polypropylene, rather than those made of polystyrene, would reduce your emissions by over 70%.

2. Targeting the energy sources for polymer production and product manufacture can significantly reduce the carbon footprint of materials.

Those responsible for procurement in universities and laboratories wield substantial influence in reducing emissions. In our research, we found the carbon intensity of the manufacture of nitrile gloves to be influenced by the electricity generating mix. By engaging with suppliers, procurement teams can understand which energy sources are used to manufacture products and purchase products from cleaner manufacturers.

3. Circular supply chains can achieve the greatest emissions reductions.

Our studies revealed that raw material production and clinical incineration are responsible for 65% of emissions linked to nitrile glove use and over 75% of total emissions related to plastic products. This underscores the significance of actions in the laboratory—such as eliminating incineration whenever possible, opting for recycling, and reusing materials and products—but also the importance of purchasing decisions that prioritise products made from recycled and waste-based polymers. Our findings indicate that when supply chains become fully circular, emissions associated with PET and PC can be reduced by over 80%, while using waste-based polypropylene and recycling at end-of-life could reduce PP emissions by 74%. Collaborating with suppliers is essential to drive upstream emissions reduction and ultimately achieve net-zero emissions.

4. Bio-based polymers may generate carbon savings but need to be considered with caution.

Our research highlighted that recovering polypropylene from waste cooking oil could reduce the emissions associated with polymer production by over 60% compared to virgin polypropylene polymer. When considering the entire lifetime of a polypropylene product, the overall emissions could fall by 24% (assuming incineration). However, the success of used cooking oil cannot be transferred to other biopolymers, as the conditions under which biopolymers are produced and disposed of are critical. The benefits of biopolymers vary significantly, with some emitting more greenhouse gases compared to their alternatives depending on end-of-life treatment and other factors. Therefore, the selection of biopolymer alternatives should be made carefully, considering the specific context. 

The issue of single-use plastics in laboratories is a pressing concern that demands immediate attention. The scientific community must recognise the environmental implications of its practices and take concrete steps to mitigate its carbon footprint. By adopting more sustainable practices and embracing circularity in supply chains, laboratories can contribute significantly to reducing their environmental impact, aligning their research with the values of sustainability and progress.