Baljot Singh Rai
Age 14 | Winnipeg, Manitoba
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INTRODUCTION
Have you ever wondered what chemicals and toxic substances are lurking in common household items? What can be more common than grocery bags! We use them every time we go shopping and we also use them to carry items from one place to another. Low-Density Polyethylene is a type of plastic which is extremely flexible and is also resistant to impact, moisture and many hazardous chemicals (‘Highlights of Low-Density Polyethylene’, 2018). Taking all of these points in consideration, Low-Density Polyethylene is often used to make grocery bags. Low-Density Polyethylene Grocery Bags have been found to contain Bisphenol A and Bisphenol S. Many of you may have heard of Bisphenol A, also known as BPA, which is a well-researched compound since it is more commonly used in the manufacturing industry (Bilbery, 2014). Bisphenol S on the other hand is a less popular, yet only slightly different version of BPA. The applications of Bisphenol S, a toxic compound, known to cause cardiovascular issues, reproductive issues as well as many other health complications (Pal et al., 2017), are very important but are also less researched than BPA. In this study I was determined to observe the presence of Bisphenol S in Low-Density Polyethylene Grocery Bags.
HYPOTHESIS
I hypothesize that yes, Low-Density Polyethylene-made grocery bags contain Bisphenol S in varied amounts amongst different stores. I made this hypothesis on the basis of research I had done, which suggested that BPA-free products may actually not be safe (Wei-has, 2018). Also, I believed that instead of BPA, there was a possibility that a similar substance was being used. The main purpose of this study was to discover what chemicals are lurking in grocery bags and to make the general public aware of their harm.
MATERIALS & METHODS
Variables: The independent variable in this project was the store from which the grocery bag used in the experiment was acquired. The dependent variable in this study was the presence of Bisphenol S in Low-Density Polyethylene grocery bags. The controlled variables in this project were the number of bags taken from each store and the amount of diluted Iron (III) Chloride solution added to each sample.
Materials: The materials required for this project were Personal Protective Equipment such as gloves and safety goggles to prevent any spillage accidents or splashes, 50.5 litres of Deionized water, disposable plastic containers, 50 Low-Density Polyethylene grocery bags (10 bags from 5 different stores), a pipette, 1.42 grams of Iron (III) Chloride, a writing instrument, a lab notebook, and a laboratory scale.
Procedure: First, all safety equipment necessary such as gloves and safety goggles were put on. Following this, the plastic containers were placed in hot water (approximately 45 ̊C / 113 ̊F) and then rinsed with water. In the next step, deionized water was boiled for the duration of 10 minutes. After, the water was poured into the plastic containers, followed by the placement of a Low-Density Polyethylene manufactured bag into the container with boiled water for 5 minutes. After the duration of 5 minutes, the Low-Density Polyethylene bag was removed from the water. To create the indicator solution, a diluted solution of Iron (III) Chloride was created, utilizing 1.42 grams of Iron (III) Chloride and 500 millilitres of deionized water. Using a pipette, 5 millilitres of the diluted Iron (III) Chloride solution were added into the water in which the Low-Density Polyethylene bag was once placed. After waiting for 5 minutes, one of the three physical colour changes into the water were observed: the water turned a dark shade of indigo or violet (high amounts of Bisphenol S were detected), the water turned a shade of green or yellow (none/very minimal amounts of Bisphenol S were detected) or the water turned into a shade of light blue or aqua blue (low amounts of Bisphenol S were detected). After performing the experiment, the results were recorded in a lab notebook. This procedure was repeated 50 times.
RESULTS
Figure 1: Amounts of Bisphenol S in Low-Density Polyethylene Grocery Bags.
Figure 2: Image of reactions. Image a: Negative; none or minimal amounts of Bisphenol S. Image b: Positive; low amounts of Bisphenol
According to the experiment, 68% of the 50 Low-Density Polyethylene grocery bags contain Bisphenol S. 44% (22) of the bags contained high amounts of Bisphenol S, 24% (12) of the bags contained low amounts of Bisphenol S and 32% (16) of the bags contained no Bisphenol S.
DISCUSSION
To break my results down, 44% of the bags contained high amounts of Bisphenol S (water turned dark indigo or violet) and 24% of the bags tested contained low amounts of Bisphenol S, which may still pose a threat to one’s health. The remaining 32% of the bags tested contained no/extremely minimal Bisphenol S, meaning that the water turned a light shade of green, or simply became yellow as the result of the addition of Iron (III) Chloride into the water. After performing my experiment, the results which were obtained demonstrate that yes, most Low-Density Polyethylene grocery bags do contain Bisphenol S!
This is a serious risk to our human health as Bisphenol S can cause obesity in children, cardiovascular health problems, disruption in hemostasis, disrupts the reproductive system as well as posing many other threats to one’s health (Pal et al., 2017; Saplakoglu, 2018). Bisphenol S can be found in many items that are labeled as Bisphenol A (BPA) free. While Bisphenol S does pose slightly different health risks than Bisphenol A, there are chances that Bisphenol S may be much more deadly, taking in consideration we do not know all of its health risks since it is less researched than BPA.
From my results, we can obtain the information that Low-Density Polyethylene grocery bags do contain Bisphenol S. This compound was likely used as an alternative to Bisphenol A, and it is likely that other items labeled Bisphenol A free such as food containers and infant drinking bottles may also contain this chemical, which can leach out of the container especially when exposed to high temperatures (Gibbens, 2019). Therefore, items such as infant bottles, food containers, and grocery bags should be treated with caution. We should switch to methods more sustainable for the environment and safer for our health, for example using reusable cloth shopping bags.
CONCLUSION
In conclusion, yes, most Low-Density Polyethylene grocery bags do contain Bisphenol S, proving my hypothesis correct. In fact, over two-thirds of grocery bags I tested contained Bisphenol S. Of that, 44 % contained Bisphenol S in high quantities, which can pose a threat to your health. Also, 24% contained rather low amounts of Bisphenol S, but may still impact your health. These bags were obtained from 5 common grocery stores (names not listed due to trademark reasons). I believe that these conclusions are important and should motivate others and myself to pursue further research in the fields of toxicology and chemistry to try to find a substance which is safe for your health.
FUTURE RESEARCH
In the future, I plan on conducting the same test on Low-Density Polyethylene grocery bags from a larger quantity and variety of stores. This will help me be more accurate on the number of bags that contain Bisphenol S. If possible, I also plan on conducting this experiment in a laboratory in which has more advanced equipment such as a mass spectrometer or a spectrophotometer. In the future, I wish to conduct this experiment on a larger number of objects such as infant bottles and food containers.
REFERENCES
1.Wei-Has, M. (2018, September 13). Why “BPA Free” May Not Mean a Plastic product Is Safe. Retrieved from https://www.nationalgeographic.com/science/2018/09/news-BPA-free-plastic-safety-chemicals-health/
2. Bilbrey, J. (2014, August 11). BPA-Free Plastic Containers May Be Just as Hazardous. Retrieved from https://www.scientificamerican.com/article/bpa-free-plastic-containers-may-be-just-as-hazardous/
3. Saplakoglu, Y. (2018, September 15). Scientists Warn BPA-Free Plastic May Not Be Safe. Retrieved from https://www.livescience.com/63592-bpa-free-plastic-dangers.html
4. Get the Facts: Bisphenol A (BPA) & Bisphenol S (BPS). (2020, April 29). Retrieved from https://saferchemicals.org/get-the-facts/toxic-chemicals/bpa- bps/
5. Pal et al. Bisphenol S impairs blood functions and induces cardiovascular risks in rats. (2017, January 1). Retrieved from https://www.sciencedirect.com/science/article/pii/S2214750017300732
6. Highlights of Low-Density Polyethylene. (2018, January 5). Plastics Make It Possible. https://www.plasticsmakeitpossible.com/about-plastics/faqs/professor-plastics/professor-plastics-highlights-of-low-density-polyethylene/
7. Gibbens, S. (2019, July 19). Exposed to extreme heat, plastic bottles may ultimately become unsafe. National Geographic. https://www.nationalgeographic.com/environment/2019/07/exposed-to-extreme-heat-plastic-bottles-may-become-unsafe-over-time/
ABOUT THE AUTHOR
Baljot Singh Rai
My name is Baljot Singh Rai and I am 14 years old. I currently attend St. Paul’s High School as a grade 9 student. I have had a keen interest in science from an early age and my curiosity has accompanied it ever since. My interests include Toxicology, Biology and Bionomics. I have been participating in science fairs for the past 4 years, since 5th grade and my interest in science has only increased since then. I am also an avid participant in my school’s Debate club, Youth in Philanthropy club and Environmental Action Committee. In the future, I plan on continuing research in the fields of toxicology.