All posts by joy01pd2014

Is my sunblock poisonous?!

Ever since I was little, my mom always made sure that I put on sunblock before going outdoors. She correctly believed that the purpose of sunblock was to prevent skin cancer, which according to the American Cancer Society is actually “the most common of all cancers, accounting for nearly half of all cancers in the United States”.  (2013). Now, as a habit, I wear sunblock every day before going outdoors for cross-country practice. My teammates make fun of me for being “paranoid”, but I think that taking precautions is important; I do not want skin cancer! I always argue about the importance of sunscreen. Thus, you can imagine the shock when I read an article called “Your sunscreen might be poisoning you” by Dr. Perry, an Adjunct Associate Professor at Columbia University on the Dr. Oz  TV show website. I was a bit hesitant about the reliability of claims from the Dr. Oz show, (an American TV talk show hosted by Dr. Oz, a teaching professor at Columbia University) since I assume from experience that TV shows are often more for entertainment and may misrepresent the truth. As a result, to clarify whether I have been poisoning myself for sixteen years, I decided to research the chemistry of sunblock: what are some common ingredients? How do they work? And most importantly, do they really harm us?

According to the University of California San Francisco School of Medicine,  there are two types of active ingredients in sun blocks: physical, which “reflect or scatter UV radiation before it reaches your skin” and chemical, which “work by absorbing the energy of UV radiation before it affects your skin.” (2013).

According to Dr. Elizabeth Hale of the Skin Cancer Foundation, the most common physical sunblock used is either zinc oxide or titanium oxide. (n.d.) In a sense, applying them is almost the equivalent of applying white paint, as they literally “block” the sunrays. (Hale, E. n.d.) For example, as seen in the image, zinc oxide is literally a white powder.

Image 1: Zinc Oxide

These physical sunblock ingredients absorb both UVA and UVB rays, which is known as “broad spectrum” (a term you should look for on your sunscreen labeling!) and are large enough particles that they do not enter into your bloodstream. (Hale E., n.d.)Thus, they are both harmless and effective. The drawback, however, is that they are not so visually pleasing unless you want to have a white layer on your face. I researched my own Avene sunblock and found it to be a physical sunblock; it is indeed very white are hard to spread apart—something I found annoying at first, but now I’m glad that at least I’m being effectively protected from the sun.

The consumers’ natural preference of a sunblock that wasn’t so “whitely” visible like a layer of paint on their faces therefore led to the development of chemical sunblock—and this is where the problem begins. One common chemical ingredient is called oxybenzone, which is a chemical that absorbs UV rays. It is so common, that according to a CNN article, “56% of beach and sport sunscreens contain the chemical oxybenzone.” (Dellorto D., 2012).

Image 2: Oxybenzone

Dr. Perry’s article on the possible poisonous effects of sunblock was referring to oxybenzone; he claimed that as an endocrine disruptor (an external compound that disrupts the physiological actions of our body’s natural hormones)(Aguirre C., n.d.), it “can cause abnormal development of fetuses and growing children… early puberty… low sperm counts and infertility… the development of breast and ovarian cancers…prostrate cancer…”. (Perry A., 2013) After reading this, I immediately looked for other sources’ claims on oxybenzone to confirm Dr. Perry’s claim. First, the CNN article referenced before reported that “The American Academy of Dermatology maintains that oxybenzone is safe.” (Dellorto D., 2012) After this, I thought, “Okay, so the government thinks that oxybenzone is safe. Then is this the Environmental Working Group and Dr. Perry crazy?”This is when I came upon an article by Dr. Claudia Aguirre of the International Dermal Institute,  which shed light on the studies causing people to blacklist oxybenzone. One study showed that the harmful effects of oxybenzone were done on rats that were ingesting oxybenzone in toxic amounts. Another study was on whether the chemical would penetrate deep into the dermis in the first place, and although the answer was yes, the study was done on skin samples in a lab—not on human beings. Finally, another study on oxybenzone “saw deleterious effects on humans”, but “the participants were asked to use about 6 times the recommended amount of sunscreen needed to prevent sunburn”. (Aguirre C., n.d.). Thus, in the end, Dr. Perry’s claim is true—but only if you use a crazy amount of sunscreen with oxybenzone.

After doing this research, I learned a lot about sunscreen, and I think it was interesting to research the chemical ingredients in our everyday products. I had always assumed that sunscreen was just some “magical” skin cancer preventer! Also, an important implication from this research is that we should never immediately trust claims made by articles online, even if the author, like Dr. Perry, is an adjunct professor at Columbia University. We should look more in depth into the studies that the claims are based on, and decide whether we want to use these products. Dr. Perry was too extreme in his claim, which confirms my initial assumption that people on TV shows tend to exaggerate and cannot always be trusted. Thus, we have to be careful to what extent we should believe in others’ claims, and of course, we should continue to use sunblock (use the recommended amount of the equivalent of a shotglass, or two tablespoons, to the face and body) (Hale, E., n.d.)!


Aguirre C. (n.d.). Shedding Light on Sun Safety – Part Two Retrieved from

American Cancer Society. (2013, March 25). Skin Cancer Facts. Retrieved from

Dellorto D. (2012, May 16). Avoid sunscreens with potentially harmful ingredients, group warns. Retrieved from

Hale, E. (n.d.) Ask the Expert: How much sunscreen should I be using on my face and body? Retrieved from

Perry, A. (2013, May 7). Your Sunscreen Might be Poisoning You. Retrieved from

University of California San Francisco School of Medicine. (2011, June 10). Sunblock. Retrieved from


Wikipedia Commons. n.d. Zinc Oxide. Graphic. Retrieved from

The Medical Dictionary. n.d. Oxybenzone. Graphic. Retrieved from

Eating a Cookie: Different Fats and their Implications

Picture 1: An Image of a Package of Mrs. Fields Cookies

Eating is one of my foremost hobbies. When my dad brought back Mrs. Fields triple chocolate cookies from a business trip, I immediately ripped open the package and began to gobble one down. Realizing that the sports season had already started, I decided to scrutinize the ingredients list in an attempt to discern whether the cookies were, according to my judgment, “too fatty to eat”. Among the many ingredients, two caught my eye— “Partially Hydrogenated Palm Kernel Oil” and “Canola Oil”. Two types of oil—normal and partially hydrogenated— were used, and I had no idea why. Eager to find out what “hydrogenated” implied, I began research on fats and hydrogenation immediately.

I had always thought that all fats such as oils were bad, because I assumed that eating fats was equal to adding fats into our body, and I sure do not want to gain weight! Thus, I favored items in the supermarket that were labeled “non-fat”. According to the Harvard School of Public Health (n.d.), however, there are “good” fats and “bad” fats. In general, saturated fats are bat fats which increase risk of heart disease, while unsaturated fats are good fats that actually decrease risk.

Fats, as seen in the image below, contain fatty acid chains. The tails consist of long hydrocarbon chains, and saturated fats have single carbon-carbon bonds, while unsaturated fats have one of more carbon-carbon double bonds. (Carter, 2011)

Picture 2: Image of Saturated and Unsaturated Fatty Acid Chains

Unsaturated fats are more beneficial to our health because a carbon-carbon double bond causes kinks in the hydrocarbon tails; the kinks make the oil less closely-packed, and thus in a liquid state. Consequently, the fat is also more easily digested. (Carter, 2011) This is beneficial to our health because according to Harvard School of Public Health (n.d.), these “good” types of fats create high-density lipoproteins (HDL) which work as “garbage trucks” that scavenge harmful cholesterol and dispose of it in the liver. On the other hand, the saturated fats create low-density lipoproteins (LDL) which carry cholesterol from the liver to the body; when there is too much LDL, deposits may form on arteries and limit blood flow–potentially causing cardiac disease.

After researching fats, I was ready to find out more about hydrogenation. The name says it all—hydrogenation is a process in which hydrogen is added to increase the melting point of unsaturated fatty acids by converting them to saturated fatty acids through a chemical reaction such as “H2C=CH2 + H2 —> H3C-CH3” (Derry, Connor, Jordan, 2008, p. 74). As seen in the chemical equation, some carbon-carbon double bonds become carbon-carbon single bonds. Interestingly, this ties to what we recently learned in IB Chemistry about the catalytic properties of period three transition metals, because nickel is used as a catalyst in the hydrogenation reaction. (Derry et al., 2008) In the process of hydrogenation, therefore, the “healthy” fats are converted into fats that may increase health risks because the carbon-carbon single bonds . These harmful fats, however, are not normal saturated fats; they are trans fats, in which the H atoms are at opposite sides of the carbon-carbon double bonds. Trans fats, according to registered dietitian, Mary Beth Sodus (2010),  “pose an even higher risk of heart disease than saturated fats.”

Picture 3: Structures of Different Fats

Picture 4: Process of Hydrogenation

After learning this, I could not understand why manufacturers would go through so much trouble—putting unsaturated oil at high heat in the presence of finely ground particles of nickel metal (Sodus, 2010)—to make our food unhealthier.  According to Sodus (2010), however, including hydrogenated fats in foods prolongs the shelf life of products because saturated fats, which are solids, have a higher melting point; the longer the shelf life, the cheaper costs are. Thus, I realized, in order to lower costs by making foods spoil slower, food companies are processing foods with hydrogenated oils at the risk of increasing consumers’ risk of clogged arteries! This exposes the negative impact of industrialization and technology, as these innovations are giving manufacturers the means to make our diet unhealthier for their own monetary benefit. The implications of hydrogenated fats are huge: they are proof that we may be hurting our bodies with these trans fats without knowing it, so we must be more cautious in choosing what to eat.

Later, after some class discussion in IB Chemistry, I realized that I completely missed out on the alternate perspective–the properties of hydrogenated fats could be beneficial to consumers. Some consumers may value the prolonged shelf life, so it is really the consumer’s decision as to whether he or she prefers more health benefits or more convenient storage and often a cheaper price.

In 2007, foods that contained more than 0.5 grams or more of hydrogenated fats, which are also known as artificial trans fats, were banned in all New York City restaurants. This ban had a positive impact on public consumption of foods, as according to journalist Amanda MacMillian, “the average trans fat content of customers’ meals <has> dropped… from about 3 grams to 0.5 grams.” Furthermore, this ban caused many restaurant chains to eliminate trans fat nationwide. (MacMillian, 2012) This is good, but in my opinion, still too lenient, as 0.49grams would still be allowed in the food. Hopefully one day, not only will hydrogenated fats be completely banned in restaurants, but also in our cookies and chips too. In the meantime, we must be more discerning when choosing what to eat. The general rule of thumb according to Harvard School of Public Health (n.d.) is, “Choose foods with healthy fats, limit foods high in saturated fat, and avoid foods with trans fat.”

From my research, discussions with friends, and discussion in IB Chemistry class, I realized that we must learn to look at things from different perspectives: I was so immersed in the fact that hydrogenated fat was harmful that I never weighed out the benefits of hydrogenated fats. I had thought that all companies that utilized hydrogenated fats just focused on maximizing profits over their consumers’ health, but then I was reminded that many consumers would prefer the convenience of hydrogenated fats. In addition, I also realized that we have to be more aware in what we eat. Awareness is so important in this age when everything, including our food, is changing daily as technology develops.

Finally, remember, if you value your health, carefully read the ingredients list and avoid hydrogenated fats!


Carter, J. S.(2011, March 12). Lipids: Fats, oils, waves, etc. Retrieved February 15 from:

Carter, J. S. (2011, March 12) Saturated and unsaturated fatty acid chains. [Online image] Retrieved February 15 from:

Derry, L., Connor, M., & Jordan, C. (2008) Chemistry for use with the ib diploma programme higher level. Australia: Pearson Heinemann

Emerald Insight, (n.d.) Hydrogenation Process. [Online image] Retrieved February 19 from:

Harvard School of Public Health. (n.d.) Fats and cholesterol. The Nutrition Source. Retrieved February 15 from:

MacMillian, A. (2012, July 16). NYC’s fat ban paying off. CNN. Retrieved February 15 from:

Mrs. Fields Cookies (n.d.) Mrs. Fields Triple Chocolate cookies. [Online image]Retrieved February 15 from:×413.jpg

University of Maryland Medical Center. (2010, November 3). Trans fats 101. Features Stories. Retrieved February 15 from: