Python Analysis: Analyzing Temperature Sensor Data in Phase Change Material Packaging for Anomalies from ISTA Standard; Unwrapping Accountability: An Analysis of the McDonald's PFAs Controversy

My technical report and STS research both focus on package sustainability, though on different aspects. In my STS research, I did a case-study on per- and polyfluoroalkyl (PFA) chemicals, which have been linked to numerous health concerns (Vandenberg et al., 2007; Flint et al., 2012, Di Nisio et al., 2018, Steenland & Winquist, 2021, Fei et al. 2009, Joensen et al. 2009), and have been used by major fast food companies as an anti-greasing agent. I identified how different groups and organizations intersect in a sociotechnical system to produce a certain outcome. Lessons from these interactions that can be applied to improve packaging sustainability in the entire fast food industry. In my technical research, I worked to find anomalies in freight shipping lane temperature data to identify gaps in phase-change material (PCM) packaging testing, which if not encompassing-enough, can lead to perishable goods (e.g. food or vaccines) fluctuating away from required constant temperatures. If PCM packaging can’t keep these products within a certain range they are thrown away. Improving food packaging testing to reflect modern, rather than historic, climates leads to more reliable results in transit, thereby reducing unnecessary waste.

My STS research is a case study that examines McDonald’s specific use of PFA chemicals in their food packaging. I revealed there is a disconnect between the company’s public sustainability commitments and actual practices. Although McDonald’s has promoted itself as prioritizing food safety and environmental stewardship, third-party investigations by Consumer Reports and a class-action lawsuit demonstrate they are doing the opposite. Despite a lack of federal regulation, consumer advocacy, existing state-level policies, cooperation between industry and the FDA, and nonprofit efforts have pressured companies to act because corporate decisions are not made in isolation. McDonald’s specifically has pledged to phase out PFAs by 2025, which is a promising change, but without third-party verification or binding regulation, such promises risk being "greenwashed." I argue that voluntary corporate pledges are insufficient in addressing systemic environmental issues. Instead, we need enforceable regulations and accountability to ensure meaningful, long-term change occurs, as my research proves that at the very least McDonalds was duplicit in its sustainability messaging vs. actual actions.

For my technical research, I interned for a Northern Virginia logistics company that noticed frequent temperature variations in shipments using phase change material (PCM) packaging, despite the packaging’s intended role in stabilizing temperatures for sensitive goods like pharmaceuticals and food. PCMs absorb and release latent heat to keep products within safe temperature ranges, but in practice, often underperform in real-world scenarios when compared to laboratory results based on International Safe Transit Association (ISTA) 7D standards. These standards simulate shipping conditions over 24–72 hours using cyclic temperature profiles, but with baseline analysis, I found they do not reflect current challenges—particularly those caused by extreme weather and climate change. In order to access this gap, I did a Python-based analysis where I cleaned, categorized, and visualized (using Matplotlib) sensor temperature data from domestic and international freight shipments. I used “thermal load”, the integral of temperature over time, as a metric for comparing real shipments with ISTA guideline profiles as it provided a single numeric output for comparison. Shipments exceeding thermal load thresholds were flagged as exceptions. Results showed that over 75% of shipments experienced temperature exceptions, and 56.3% failed to meet ISTA’s longest cyclic profile. Winter shipments were especially vulnerable, with more than 50% exceeding acceptable thermal loads. These findings suggest that ISTA 7D standards may not adequately capture real-world variability and there is a need for more robust testing protocols. By improving these standards, the risk of products perishing during transit can be decreased which reduces waste.

For this thesis, I wanted to focus on sustainability in my research. However, because my technical research was done before my 4th year and already on freight packaging and logistics, in order to have a common focus, I knew I needed to choose something related to packaging. Since I am a consumer of fast food products that are known to contain PFAs and other toxic chemicals, the issue was more personal, and interesting, since I discovered consumer action can have an impact on corporate sustainability. Both projects were enlightening in the inner workings of industry, and the complexity behind what may seem like a simple choice to consumers. My technical research showcased that corporate sustainability sometimes can be beneficial from a monetary standpoint for companies, in addition to being better for the environment.

School of Engineering and Applied Science

Bachelor of Science in Computer Science

Technical Advisor: Briana Morrison, Rosanne Vrugtman

STS Advisor: Kent Wayland, MC Forelle