Hidden Chemicals in Children’s Toys

                                                                                               Posted by Bray Fedele

When considering the places cancer causing chemicals could be hiding, children’s toys are likely not the first category that comes to mind. Dr. Stapleton, a chemist at Duke University, was among the masses who did not previously consider toys for children we strenuously attempt to protect to be home to several “lurking” chemicals. After noticing a familiar flammability standard tag on her one year old’s play tunnel, Stapleton, being the resourceful chemist she is, immediately took a piece of the tunnel to her lab for analysis. Having already researched the effects and presence of flame retardants on human health, she was horrified by what she found.

Stapleton was shocked to find a flame retardant, chlorinated tris, which was banned for use by manufacturers in baby clothes years prior for its ability to alter DNA and even cause cancer. So what was this chemical doing so unquestioned in presumably safe baby toys?

Figure One: Chlorinated tris, a commonly used and toxic flame retardant.

 The use of flame retardants in different materials began in the 1970s in order to meet flammability requirements. Since then, chemists have raised several concerns about the role of formulations with bromine, chlorine, and phosphorus in the development of serious diseases and even death. These chemicals, once in fabrics and other home materials, have the potential to escape into the air and enter the human body as dust (usually by small children putting their hands and other materials in their mouths). These specific chemicals used in flame retardants have been associated with cancer, disruption of hormones, harm to the reproductive system, neurodevelopmental problems, lower I.Q., and even behavioral problems. In fact, brominated flame retardants have recently taken the crown as the major cause of I.Q. loss and intellectual disability in children.

Figure Two: Most common flame retardants used as of 2019. 

Despite these findings, flame retardants are loosely regulated, and have never been banned federally (as of 2020). Manufacturers easily find loopholes in producing their goods with harmful retardants by constantly changing the type, in order to stay ahead of scientists. For example, a chemist at the University of California successfully proved the association of brominated tris and cancer in 1977, but manufacturers quickly avoided the problem by switching to a close relative, chlorinated tris. Thus, scientists had to work at a rapid pace to constantly prove the detrimental effects of different flame retardants, and still are not fully able to ban their use entirely. There is a never ending list of flame retardants being used by manufacturers, making it almost impossible for scientists to identify them all, let alone test them for safety and reliability. In addition, the full discontinuation of toxic flame retardants is seemingly a complicated endeavor, as the use of chlorinated tris has been removed from the manufacturing process of children’s clothes over 40 years ago, yet it is still used in baby toys.

Figure Three: Types of brominated flame retardants. 

In 2017, scientists discovered that mothers had 15 times less flame retardant concentration in their urine than their children. Upon further investigation, there was an

association determined between the number of baby toys in the home and the concentration of flame retardants in the child’s urine (the more toys, the higher the concentration). Such findings are extremely worrisome considering the previously discovered health effects of flame retardants and their threat towards crucial development expected in the first year of life (and throughout adolescence). Scientists like Dr. Stapleton and many others have made it their mission to have these toxic chemicals banned from household items for good, but it is a slow and daunting process and ultimately needs federal support in order to ease the minds of parents and to save the lives of children.

Sources:

1. Gross, L. (2020, November 23). The harmful chemical lurking in your children's toys. The New York Times. Retrieved November 15, 2021, from https://www.nytimes.com/2020/11/23/parenting/home-flame-retardants-dangers.html.

2. The flame retardants market. FLAMERETARDANTS. (n.d.). Retrieved November 15, 2021, from https://www.flameretardants-online.com/flame-retardants/market. 

 

                                       Lithium battery vs hydrogen fuel cell

                                                        view one

Elon Musk: Hydrogen fuel cells are "incredibly stupid"! 

As early as 2015, he claimed: "If you want to choose an energy storage mechanism, you should choose methane or propane, because they are easier to produce." Musk said: "I just think (hydrogen fuel cell) is very stupid... .... It is very difficult to make hydrogen, store it and use it in a car.", "If you take a solar panel to directly charge the battery pack, compared with electrolysis, hydrogen is taken, oxygen is separated, and hydrogen is compressed... .. This is about half of its efficiency."

In fact, Musk's words are not unreasonable. Compared with batteries, the energy conversion efficiency of hydrogen fuel cells is always lower than that of batteries. Compared with Tesla’s BEV efficiency, the best FCV currently on the market is still less than half of the BEV in efficiency; in addition, the development of the industrial chain In terms of infrastructure (hydrogen refueling station) construction, the gap between hydrogen fuel cells and lithium batteries is still decades away.

The development of fuel cells continues, but the charging infrastructure, the mass production of hydrogen, and its inventory are lagging behind. The use of hydrogen requires a lot of infrastructure construction, high quality, and large pressure accumulators. The production of fuel cells, pressure tanks (carbon fiber), the price of hydrogen for refueling, the infrastructure of hydrogen refueling stations, and the construction of H2 production facilities are all too expensive. In addition, at present, thermochemical processes using fossil energy as raw materials are widely used in industry, mainly including hydrogen production methods such as hydrocarbon steam reforming, heavy oil partial oxidation, coal gasification, and water electrolysis. In the mainstream hydrogen production process, there are also problems of pollution and low efficiency.

View Two:

"The future market belongs to fuel cells"

For many years, Toyota has been betting hydrogen fuel cells on battery electric vehicles to achieve its zero-emission vehicle strategy. Toyota's fuel hydrogen battery is an advanced technology used by Toyota in Mirai's new energy vehicles. Toyota hydrogen fuel cell is like a power station. It produces electricity through the chemical reaction of oxygen and hydrogen. It does not need to be charged like ordinary storage batteries. Only need to add hydrogen to produce electricity through chemical reactions.

The battery life advantage of the hydrogen fuel cells is also obvious compared with lithium batteries. It also has a battery life of 500 kilometers. It takes a long time for an ordinary lithium battery to charge, super fast charge also takes one and a half hours, and hydrogen dye battery can be filled with hydrogen in only 3 minutes. . In addition, hydrogen far surpasses lithium-ion in energy density, and the two are not even on the same order of magnitude.

Hydrogen fuel cell vehicles also have the following advantages:

1. Hydrogenation is like refueling, usually only 3~5 minutes. The charging of electric vehicles is a slow process. Even if Tesla launches a supercharging station, it usually takes more than an hour.

2. The main component of a hydrogen fuel cell is hydrogen. We know that the chemical formula of water is oxygen dihydrogen. The hydrogen fuel cell will not pollute the environment after the end of its service life. Lithium-ion batteries contain a lot of heavy metals. If they are not recycled properly, they will cause greater pollution to the environment.

3. Hydrogen fuel cells have high energy storage density, lightweight, and generally longer cruising range. Usually, more than 500 kilometers and pure electric vehicles are based on the size of the battery capacity. At present, most pure electric vehicles have a cruising range of about 300 kilometers, and a few models can reach 400 to 500 kilometers.

Fuel cell vs lithium-ion battery

Currently, the global energy and environmental systems are facing huge challenges. Among them, the automobile industry, which is a major consumer of oil and carbon dioxide, is also facing a revolutionary change. The use of pure electric drive including pure electric and fuel cell technology as the main technical direction of new energy vehicles has become the world Consensus formed by various countries. Fuel cell vehicles are another important direction of electric vehicle batteries. Compared with lithium-ion batteries, it can be clearly seen that there are obvious advantages and disadvantages between the two.

First of all, it is from the perspective of security.

Safety hazards of fuel cells: Leakage and control of hydrogen is the main source of safety hazards in fuel cell systems, which belong to the physical level, while the safety hazards of lithium-ion batteries mainly come from chain reactions that are not easy to control, which belong to the chemical level. Because the chain reaction speed is extremely short. In terms of controllability, the control difficulty of lithium-ion batteries is higher than that of fuel cells. However, in the case of extreme violent collisions, the degree of harm to fuel cells is even greater. Of course, this is only in theory. The hydrogen itself has a short leakage time due to its fast escape. In addition, the high-pressure hydrogen cylinder is resistant to impacts, drops, gunshots, and other unconventional properties that also provide security.

Secondly, from the perspective of low-temperature performance.

Because the viscosity of the electrolyte increases at low temperatures, the conductivity decreases, which will lead to a sharp increase in the internal polarization of the battery. Generally, manufacturers do not recommend sub-zero discharge behavior. Therefore, lithium batteries need external heating to solve the low-temperature problem. The low-temperature start performance of the fuel cell is poor, but with the increase of its own heat release after startup, the temperature of the stack will quickly stabilize in the normal operating temperature range of 80-90°C. However, how to achieve low-temperature startup of fuel cells, especially low-temperature startup under the premise of not using external auxiliary power, is an important research topic.

Third, it is from the perspective of cost.

On the whole, whether it is a fuel cell or a lithium-ion battery, the price is higher than that of traditional energy sources. In particular, the complexity and harsh conditions of the source, storage, and safe use of hydrogen have resulted in high costs for hydrogen fuel cells, making it difficult to gain advantages in the short term. Judging from the mass production data, the cost of fuel cells is still very high, and it is expected that the price of internal combustion engines may be close to the current price of internal combustion engines under the premise of long-term mass realization.

Fourth, the time it takes to charge.

Long charging time is always an indelible pain point for lithium-ion batteries. In the normal charging mode, a car equipped with a lithium-ion battery takes 3 to 8 hours to fully charge. In contrast, fuel cells are much more convenient and fast. Taking hydrogen fuel cells as an example, it only takes 3 to 5 minutes to directly add hydrogen to resurrect with full blood.

Fifth, the cruising range.

This may be the biggest pain point for pure electric vehicles, especially lithium-ion battery vehicles. It is difficult for traditional lithium-ion batteries to exceed 500km in endurance. In contrast, fuel cells with high energy density and lighter weight can reach farther in endurance.

Sixth: Temperature influence.

Fuel cell vehicles can maintain the same long cruising range as in summer through the integrated thermal management of the entire vehicle. This is something that lithium-ion batteries cannot do. Lithium-ion batteries consume power regardless of whether it is PTC heating or air conditioning heating. The fuel cell consumes electricity to power the air conditioner in the summer, while in the winter it only uses waste heat to keep the passenger compartment warm. So theoretically, the mileage in winter should be longer than in summer. At present, there are institutions that are carrying out research on waste heat power generation based on the Rankine cycle. If it can be realized, it will further improve the efficiency of fuel cells.

Seventh: Cost balance.

Fuel cell and pure electric vehicles have different cost balance points. Passenger cars are about 500 kilometers away, and commercial vehicles are about 100 kilometers 

Reference:

1].https://www.fz-juelich.de/portal/DE/Forschung/EnergieUmwelt/energiewende.html

[2].https://www.chemie.de/news/1153224/batterie-oder-brennstoffzelle.html

[3].https://traveltosetna.wordpress.com/2018/10/08/brennstoffzelle-lithium-ionen-akku-feststoffzelle-was-ist-besser/

[4]. https://www.zhihu.com/question/19986795

[5]. http://www.sohu.com/a/204402016_15

New Quarantine Activity: Firing Medieval Cannonballs

                                                                                                            Posted by Ava Sheftik

 An article titled “This Chemist’s Pandemic Hobby? Firing Medieval Cannonballs” found in the New York Times discusses an activity of Dr. Dawn Riegner, a professor of chemistry at the United States Military Academy West Point, early quarantine activity. She convinced her colleagues and daughter into beginning a study on how well different kinds of gunpowder recipes from the Middle Ages performed.

Their report on their gunpowder analysis was featured in Omega which is a peer reviewed journal of the American Chemical Society. The purpose of their experiment was to determine if the creators in the medieval time period actually understand the chemical characteristics of their materials and processes that they were completing. They analyzed gunpowder recipes which consisted of potassium nitrate (KNO3), charcoal (C), and sulfur (S8) by bomb calorimetry. They then used this to determine their enthalpies of combustion and differential scanning calorimetry to determine their pre-ignition and propagative ignition enthalpies.

The cannon used for the range tests was a reproduction of a Steinbüchse, which is a stone throwing cannon, copied from an extant gun from the 15th century. For safety reasons the gun had some alterations but nothing that should have affected the shot.

Figure 1. Heats of Combustion for Each recipe in Chronological order

This figure represents the thermodynamic potential of gunpowder recipes in chronological order. The suggestion for the change in these recipes is because they needed to have safer ones that did not put the gunners at risk or damage the cannons. The trend observed is that the closer the KNO3:C ratio is, the heat of combustion will be higher and reaction rate will be faster.

The bomb calorimetry data shows that increasing the percent of charcoal will lead to a higher heat of combustion. Furthermore, most samples that were pressed produced a slightly lower thermodynamic potential. This may be due to the lack of oxygen ability to enter to materials due to the lack of spacing between the particles in the pressed sample. Therefore, incomplete combustion would be the result and is the explanation for the smaller enthalpies observed for the pressed samples.

There were several additives also tested: water, varnish, vinegar, and brandy.

It was determined that the addition of water and its effect on enthalpy was specific to each different recipe. However, the addition of varnish to a recipe with high charcoal content and relatively low sulfur content decreases the potential energy measured by the bomb calorimeter. The varnish can provide clumping of the ingredients and prevent sulfur from mixing and which then decreases the surface area of the charcoal.

The addition of brandy as a corning agent did not show a significant increase in the heat of combustion. The suggested reason for this is that it provided missing organic compounds for better quality burning

 Figure 2. Addition of varnish

Figure 3. Addition of Brandy

The addition of vinegar requires further studies to come to an ultimate conclusion. It was added to enhance mixing of dry ingredients so that they didn’t separate during transport. Some recipes produced a result that was similar to water, some yielded a lower enthalpy, and some yielded higher.

Figure 4. Pre 1400 vs. Post 1400 ingredient ratios and their impact on the heat of combustion

As time progressed throughout 1300s to1400s the recipe creators were creating a formula that would provide them with a lower heat of combustion which involved increasing the amount of potassium nitrate. After the 1400s the heat of combustion rose again and the potassium nitrate decreased.

These advancements completely changed the nature of warfare during the time period. Sieges that used to take years and months began to only take weeks and days. The guns were now safer for the gunners; however, they became larger and more effective in their use.

References

Broad, William J. “This Chemist's Pandemic Hobby? Firing Medieval Cannonballs.” The New York Times, The New York Times, 7 Oct. 2021, https://www.nytimes.com/2021/10/07/science/gunpowder-medieval-cannons.html.

Ritchie, T. S.; Riegner, K. E.; Seals, R. J.; Rogers, C. J.; Riegner, D. E. Evolution of Medieval Gunpowder: Thermodynamic and Combustion Analysis. ACS Omega 2021, 6 (35), 22848– 22856. 

 

Bombs Away!

 During the beginning stages of the Covid-19 pandemic in 2020, many of us were using our time in quarantine to practice new hobbies such as baking bread, making whipped coffee, or hoarding toilet paper. For students and researchers at the United States Military Academy in West Point, New York, however, time in quarantine took a more explosive turn. In his article "This Chemist’s Pandemic Hobby? Firing Medieval Cannonballs" for the New York Times, author William Broad chronicles Dr. Dawn Reigner and her team as they tested different medieval recipes for gunpowder to discover what causes the most reactive explosions - and further understand how this chemical innovation changed the course of history forever.

The commonly known, tried and true recipe for gunpowder has consisted of saltpeter (potassium nitrate), carbon, and sulfur. These ingredients create an exothermic reaction that is used to propel bullets, cannonballs, and other similar weapons. Recipes date back centuries and all include these three main ingredients. Interestingly, there are medieval records of less common ingredients being added to the mixture such as brandy, vinegar, and quicklime were added in small quantities. Dr. Reigner and her team decided to test these additions to find the recipe for the most efficient gunpowder.

Figure 1: Simple equation for the combustion reaction of gunpowder

Broad notes in his article that gunpowder changed the nature of warfare, in that kingdoms needed armies as opposed to simply fortresses. Perfecting the recipe of gunpowder was also necessary, as large explosions would kill or maim those wielding the weapons themselves.

Dr. Reigner's group noted that in trying to create more effective explosions that were safe for the user, recipes were tweaked so as to lower the heat of combustion to safer levels while still having a large enough blast to damage structures and maim enemies. The researchers noted the changes over time and compared them to their own bomb calorimeter data.

Figure 2: Mass percentages of gunpowder components over time and bomb calorimeter data

Their research showed that the data surrounding the interesting additions to the recipes, like brandy, were inconclusive but did not show measurable difference. The biggest effect on the heat of combustion was the amount of saltpeter, also the most expensive ingredient, which was lessened in post-1400 recipes. Reigner's research shows that the trial and error method that medieval people used to perfect gunpowder is not dissimilar from the way research is conducted today, and that even in the 1300's people were striving to understand and perfect the way things are done.

References

Broad, W. This Chemist’s Pandemic Hobby? Firing Medieval Cannonballs. The New York Times, October 2021, Retrieved from https://www.nytimes.com/2021/10/07/science/gunpowder-medieval-cannons.html

ACS Omega 2021, 6, 35, 22848–22856

Publication Date:August 24, 2021

https://doi.org/10.1021/acsomega.1c03380

Coffee, Climate Change and Why We Need to Save the Planet NOW!

 New study shows that the growth of species of coffee plants (Coffee Arabica and Coffee Canephora) is negatively impacted by climate change. 

Close your eyes and picture this scene: You're sitting at your desk, early in the morning, dreading the work day ahead of you. You didn't get good sleep the night before and can feel the stinging in your eyes caused from a lack of sleep. Then you take a deep breath in, and as you breathe in you get a whiff of a subtle, roasted, slightly fruity aroma. The smell of caramel fills up your nose as well as the warmth of steam. You turn around and see that the coffee you were brewing is now ready to drink. Your mood changes as you grab that warm cup of happiness containing a little piece of heaven and bring it to your lips, and from the first sip you feel energy and positivity flow in and your outlook changes. Supposedly. I am not a coffee drinker myself but I have heard wonders about this magic drink. Regardless of your stance, that warm cup of coffee may begin to taste different as time goes on and may begin to smell worse and it's all due to climate change. 

A new study conducted by a research group in Tufts and Montana State University's Friedman School of Nutrition Sciences and Policy shows how a variety of environmental factors are negatively affecting the quality of coffee that is grown, affecting the coffee's aroma and taste (ScienceDaily, 2021). The study also found that apparently the quality of the coffee is affected by shifts in the climate occurring due to climate change as well. 

The quality of the coffee was determined based upon sensory attributes (Aroma and taste) as well as the presence of primary and secondary metabolites. The primary metabolites and secondary metabolites present in these coffee species include things such as sugars, lipids, vitamins and minerals as well as caffeine, trigonelline, chlorogenic acids and terpenoids some of which are depicted in the figures below. 

From left to right: Caffeine, trigonelline and isoprene, a type of terpenoid.

The study found that 2 factors were the most significant in affecting the quality of the coffee: the altitude in which the coffee is grown at as well as the amount of exposure it has to sunlight (Ahmed et. all, 2021). Some of the other environmental factors that affect the quality of the coffee's taste and aroma include water stress, increasing temperatures and increased carbon dioxide emissions. These environmental factors play an important role in determining where suitable places for coffee growth are however. The top 2 factors of altitude and sunlight exposure are geographical variables, however the other factors such as water stress and increasing temperatures are directly linked to climate change. Because of this, the lands that were once suitable for coffee production are now losing their quality. 

The figures above show the results found from the research study, which show that an increase in altitude results in higher quality coffee and that increased light exposure results in lower quality coffee. 

An example of lands that are losing their coffee production abilities can be found in Nicaragua. According to various projections, 90% of the coffee growing land in Nicaragua will disappear by the year 2050 due to changes in the climate that will occur. Conversely, coffee producing regions in East Africa and Asia have been identified as becoming spaces that are more suitable for coffee production in the near future, due to climate change. However, in order for these lands to access these new will cause for deforestation to occur, which will impact the biodiversity of the regions and have other negative effects such as increased gas emissions.

Some of the solutions that the study found that could work are shade management, pest management and selecting for climate-resistant wild coffee plants. However these are short terms solutions that won't really combat the long term drastic effects of climate change. In order to truly save our coffee and our planet we must look to long term solutions that will have a more permanent effect on the climate. 

Author: Anas Mahmoud 

References

Ahmed, S., Brinkley, S., Smith, E., Sela, A., Theisen, M., Thibodeau, C., Warne, T., Anderson, E., Van Dusen, N., Giuliano, P., Ionescu, K. E., & Cash, S. B. (1AD, January 1). Climate change and coffee quality: Systematic review on the effects of environmental and management variation on secondary metabolites and sensory attributes of Coffea Arabica and Coffea canephora. Frontiers. Retrieved November 2, 2021, from https://www.frontiersin.org/articles/10.3389/fpls.2021.708013/full. 

Isoprene. ChemSpider. (n.d.). Retrieved November 2, 2021, from http://www.chemspider.com/Chemical-Structure.6309.html?rid=05410d7d-dfb5-4ca1-a2f8-46e2f841ed01. 

Snider, M. (2021, September 2). Go ahead, have that Third Cup of coffee. you just might live longer, new research suggests. USA Today. Retrieved November 2, 2021, from https://www.usatoday.com/story/news/health/2021/09/02/how-much-coffee-healthy-three-cups-reduce-heart-attack-risk/5668047001/. 

Putting an End to Toxic 'Forever Chemicals'

 In The NBC article “Toxic ‘Forever Chemicals’ are Everywhere. The EPA has a New Plan to Crack Down”, Leigh Ann Caldwell and Frank Thorp V explain the crisis on PFAs and the steps that are being followed in order to protect the nation from these harmful chemicals. 

Figure 1: The chemical structure of PFAs.

PFAs, commonly referred to as “forever chemicals” are materials that cannot be broken down due to strong carbon-fluoride bonds. These chemicals are able to seep into groundwater or released into the air and cause harmful health conditions such as high cholesterol, immunosuppression, infertility, cancers, and reduced vaccine efficiency.  Two of the biggest polluters of these PFAs are the Department of Defense and the chemical manufacturers. These polluters are consequently infecting people that live in these areas, such as the instance mentioned in the article where a woman grew up next to a Navy base and possibly ingested these chemicals. As a result, she developed melanoma at the age of 25.

Figure 2: Naval Air Development Center in Warminster, Pennsylvania.

Although these organizations are responsible for environmental pollution of PFAs, they are not the only source. Food packaging products, pans, clothes, shoes, carpets, and cosmetics are also found to have these toxic chemicals within them. 

Figure 3: Examples of products that contain PFAs.

The issue has been known for quite some time now, but the only action that was taken was the monitoring of water near contamination sites. Even then, very little has been done to rectify the contamination. Now, the EPA is creating a plan to implement new requirements and restrictions for drinking water PFA contamination. These regulations will be set by Fall of 2023. In this plan, the amount of PFAs present in drinking water must in the acceptable range, which the FDA recommends to be 70 parts per trillion. The EDA is also planning to restrict companies from dumping these chemicals into waterways. In October, California has banned the use of PFAs in baby and toddler products and these type of actions are likely to be followed by other states, as well.

Sources: 

https://www.nbcnews.com/politics/politics-news/can-epa-get-rid-toxic-forever-chemicals-n1281707

https://www.pfasfacts.com/

https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.riversideca.gov%2Fpress%2Funderstanding-pfas&psig=AOvVaw16g0ZO0biEFG0Qw3uLWoAa&ust=1635864463032000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCPjinJe09_MCFQAAAAAdAAAAABAX