Conclusion: Tear Gas, Pepper Spray, and Chemical Weapons

 

According to reputable official the Honorable Mr. Andrew C. Weber, the Assistant Secretary of Nuclear, Chemical, and Biological Defense programs, “the Office of the Assistant Secretary of Defense for Nuclear, Chemical and Biological Defense Programs has a wide range of duties related to countering Weapons of Mass Destruction (WMD) threats.  Their team of top scientists helps us understand these threats and engage in activities and programs to counter them.  Their duties include overseeing Department of Defense science and technology investments in countermeasures that will enable the United States forces to prevent, protect against, and respond to WMD threats”. However there is still one chemical weapon that is marketed to the masses today and even used against protests: tear Gas.

Tear gas in use

Tear gas was first introduced World War I by the French. It was not very concentrated, and the Germans hardly noticed it was being used. In August 1914, the French fired 26 mm grenades containing ethyl bromoacetate, but the low concentration, only approximately 19cm³ per grenade, was not enough to bother the Germans. Afterwards, due to shortages of bromine, the primary chemical was switched to chloroacetone. The Germans then retaliated with a tear gas of their own making, using it for the first time in October of 1914 on the British. Again, the weapon was so dilute that the enemy combatants did not even notice.

Peaceful protesters in Tahrir Square attempt to flee from the noxious tear gas

Since its debut in the Great War, tear gas, and its famous derivative pepper spray, has transformed from an ineffective weapon of war to a highly efficient tool for dispersing protesters. It has become a lynchpin in the arsenal of modern authoritarian regimes and has seen widespread use in recent years, with the Arab Spring and the Turkish protests being the more high-profile international cases. In an especially ironic incident, tear gas manufactured in the US, the great champion of democracy, was used on protesters in Tahrir Square attempting to enact some democratic reform. In Turkey, when Prime Minister Erdogan tried to seize historic sites and develop them for his cronies, protesters invaded Taksim Square; they were tear gassed. Luckily for them, the tear gas brought international attention to their plight, but that cannot be said of all tear gas victims.

A doctored photograph which emphasizes the inhumane actions of Lt. Pike, who had pepper sprayed a peaceful protester.

Another event exemplifying the political, rather than physical, power tear gas can have was the UC Davis Occupy protest that involved Lt. Pike, a police officer who had pepper sprayed a peaceful protester for no apparent reason. The ensuing media firestorm brought new attention to the waning Occupy Movement, showing that chemical weapons aren’t always so bad. Also, the image of the cop pepper spraying the protesters birthed many amusing pictures, another positive effect of chemical weapons.

3-D Model of 2-Chlorobenzalmalononitrile (CS)

Although tear gas has numerous different forms, 2-Chlorobenzalmalononitrile (also known as CS) is the most common. CS has a chemical formula of C10H5ClN2, composed of several cyanide functional groups, Due to the hydroscopic nature of aerogels, a type of colloid, when silica aerogel is combined with CS, the fluidity, water resistance, chance of exposure and intensity of the symptoms increase.  CS gas is synthesized by the reaction of 2-chlorobenzaldehyde and malononitrile through Knoevenagel condensation. This reaction is composed of two steps: first, the nucleophilic addition of an active hydrogen compound to a carbonyl group and second, a dehydration reaction in which a molecule of water is removed. of the symptoms increase

CS-chemical-synthesis.png

ClC6H4CHO + H2C(CN)2 → ClC6H4CHC(CN)2 + H2O

There are a couple major components in tear gas. Charcoal is used as an ignitor when combined with potassium nitrate allowing the can to combust. This is because potassium nitrate gives off great quantities of oxygen when it burns, feeding the fire, while charcoal will begin to smolder when the pin is pulled. Silicon is also added so that when the exothermic reaction of potassium nitrate occurs causing super hot glass droplet to forms, igniting the other compounds. The sucrose in the can acts as a fuel source for the fire at a relatively low temperature, vaporizing the O-Chlorobenzalmalononitrile, a lachrymator, irritating the eyes or the nose. Potassium chlorate is an oxidizer creating some of the smoke, while magnesium carbonate is used to to keep the solution slightly neutral. This is all dispersed in nitrocellulose, a sticky binding, to create a homogenous mixture.

Although technically banned under the UN Convention on Chemical weapons, tear gas is not nearly as lethal as other compounds such as Ricin or Sarin gas. In fact it has to be 25 grams per cubic meter for it be lethal when only concentrations 4 grams per cubic meter are used to disperse crowds. However it is still worrying to note that chemical weapons are not just abstract concepts, created in sinister labs in shady countries, but actually used today, even here in the US.

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Manufactured Bane of Humanity: Agent Orange

One of the numerous operations in order to clear the vegetation utilizing Agent Orange

Like sarin gas and ricin, Agent Orange is a commonly known chemical weapon due to its controversial usage during the Vietnam War. However, Agent Orange’s intended targets are not human beings; instead, the substance’s purpose is to act as an effective herbicide. Due to its widespread usage during the Vietnam War, veterans from the war and the local vietnamese population were affected by Agent Orange’s deleterious effects on humans. Although Agent Orange is no longer utilized due to its dangerous nature,generations can still feel the after-effects of its usage in Vietnam more than 40 years ago.

An orange barrel containing equal amounts of 2,4,5-T and 2,4-D. Due to the orange color of the barrel, the herbicide was nicknamed “Agent Orange.”

The name, Agent Orange, began as a nickname given to the chemical agent by military personnel because of orange-colored stripes  located on the barrels which contained Agent Orange. Agent Orange is actually a mixture of equal amounts of 2,45-Trichlorophenoxyacetic acid (2,4,5-T)and 2,4-Dichlorophenoxyacetic acid (2,4-D). Both of these are phenoxy herbicides, which affect the growth hormone indoleacetic acid (IAA). When plants are exposed to phenoxy herbicides, they undergo rapid, uncontrolled growth and this eventually kills the plants. In theory, these phenoxy herbicides should have little to no effect on humans; however, there was a significant amount of data connecting 2,4,5-T to adverse side effects and harm for exposed humans.

in 1969, scientists discovered that the 2,4,5-T was contaminated with dioxin, 2,3,7,8-tetrachlorodibenzodioxin or TCDD and that it had caused these unexplained adverse side effects. TCDD wasaccidently created as a byproduct due to the incomplete combustion reaction during the production of 2,4,5-T. Due to exposure to TCDD during the production and utilization of phenoxy herbicides, more than 18,000 factory workers and sprayers had perished. The World Health Organization states that dioxins like TCDD are lethal to human beings as they can cause reproductive and developmental problems, damage to the immune system, interference with hormone production and finally, cancer. Many concluded that TCDD was “perhaps the most toxic molecule ever synthesized by man.

A graph which details the numerous negative physiological effects due to Agent Orange

The lethality behind TCDD is not due to its effectiveness but its versatility; TCDD affects numerous different metabolic processes and describing the researched effects of TCDD would take hours. Therefore, only one of TCDD’s effects  will be discussed: the effects of TCDD on thyroid hormone metabolism and function in victims of TCDD poisoning. One scientific study discovered that chronic exposure to TCDD had led to a decrease in thyroid hormones and these altered levels of hormones could promote cancer. Although this specific aspect of TCDD in relationship to thyroid hormones has been explained, TCDD diversified effects on the human body is still being studied and further research will be fruitful in diagnosing, treating and curing TCDD production.

Chemical process behind the manufacturing of Agent Orange

Even though Agent Orange was not utilized as a  weapon specifically against human beings, its toxic byproduct, TCDD, has caused numerous casualties. After the Vietnam War, thousands of veterans and affected Vietnamese faced severe medical conditions as well as deformities in their newborn children. The aftermath was gruesome, and currently, TCDD production as a chemical weapon has not been initiated by any country. However, in order to keep this potentially catastrophic chemical weapon from being used,more legislation towards more restrictions on the production and usage of chemical weapons is necessary. However, the first step towards solving this problem is by spreading awareness and to prevent our generation and future generations from making the same mistake.

Chlorine Gas: The Grandfather of all Chemical Weapons

Although many people like to believe that something as evil and heinous as chemical weapons were invented by super secret military instillations or by communists, the origin of chemical weapons is even more surprising. Is it believable that the father of chemical warfare is actually responsible for most of the people on this planet?

Fritz Haber was a controversial chemist who lived in Germany from 1868 to 1934. The creator of one of the most influential and significant discoveries of the 20th century, Fritz Haber created the Haber-Bosch Process in 1909, which allowed for the creation of ammonia.

How the Haber Bosch Process Produces Ammonia

How the Haber Bosch Process Produces Ammonia

This lead to a dramatic increase in fertilizer and subsequently food production, allowing for the planet to support the seven billion people today. The discovery prompted him to receive the 1918 Nobel Prize in Chemistry for his work and launched him to international acclaim. However Haber, not satisfied with his wonderful service to humanity, opted for a darker path and became the lead supervisor of Germany’s poison gas program during World War I. Ammonia as it turns out was crucial to produce nitrates and explosives and Haber, himself, proposed the militarized use of chlorine gas as a weapon, first successfully used in the Second Battle of Ypres in 1915.

Chlorine Gas Attack during the 2nd Battle of Ypres in WWI

Chlorine Gas Attack during the 2nd Battle of Ypres in WWI

Chlorine gas was the first chemical agent used to bring about large-scale death and destruction in the history of warfare, leading people to create even more monstrous and atrocious chemical weapons in order to make this system of murder all the more effective. Although Chemistry is responsible for the quality of the food we eat, the medicine we use, and even how we think and act, it is important to note that not everything is sunshine and rainbows and chemistry can be used for much malice in the wrong hands.

Chlorine is usually found in the form of sodium chloride, or table salt, which is perfectly benign, but in its diatomic form it is an extremely poisonous. It is a greenish yellow gas at room temperature and atmospheric pressure, and consists of two chlorine atoms single bonded together, forming Cl2.

Ball and Stick Model of Diatomic Chlorine

Ball and Stick Model of Diatomic Chlorine

It is the second lightest halogen gas, meaning that it is extremely electronegative, reacting with many different elements and producing a wide variety of compounds. These compounds range from calcium chloride, which can be used to melt snow on the sidewalk, to disulfur dichloride, which is used in thevulcanization of rubber. Chlorine gas has a molar mass of 70.90g/mol, meaning that it is about 2.5 times heavier than air, primarily composed of nitrogen and oxygen having molar masses of 28.02g/mol and 32.00g/mol respectively. Sending an electric current through an aqueous sodium chloride solution can easily produce this gas, a process called electrolysis.

Simple view of electrolysis producing chlorine gas

Simple view of electrolysis producing chlorine gas

But how does this incredibly deadly chemical compound actually work? Since chlorine is incredibly reactive, when breathed in it will react with the water in the lungs to create hydrochloric acid or HCl. The HCl would corrode the tissue in the lungs, causing them to fill up with fluid, drowning the individual. Because of its large mass, it would just settle in the trenches when released, waiting to strike. It was such a gruesome way to die, Wilfred Owen, a famous poet who served in the British army during WWI, described the horrifying effects in his famous poem. The reason this happens is because Chlorine is a very strong oxidizer, or an element that accepts electrons from other compounds in a redox reaction. According to theCDC, Chlorine can also cause irritation in the eyes, throat and skin, watery eyes, and wheezing, reacting with the water in these areas.

A graphic detailing a list of symptoms that may arise from an exposure to chlorine gas

A graphic detailing a list of symptoms that may arise from an exposure to chlorine gas

Aside from its extremely potent nature chlorine has many important applications and is still produced today. Chlorine is used as a disinfectant in swimming pools and has many functions in producing consumer goods, like plastics, dyes and pharmaceuticals. It is even used in sucralose or Splenda, an artificial sweeter said to be 600 times sweeter than sucrose, or table sugar.

Sucralose, more commonly known as Splenda.  The green presents chlorine

Sucralose, more commonly known as Splenda. The green presents chlorine

As a result chlorine is still mass-produced, the amount increasing as more uses are discovered. This dilemma serves to show that although chlorine gas, like many other compounds, is incredibly dangerous and has been used to kill people in the past, it can be extremely useful to society. Even compounds that are normally viewed as being extremely important to society, like ammonia, can be used for nefarious purposes. In the end, chemistry and its applications are just tools that can be used to solve momentous problems, or create new ones. It all depends on how these discoveries are used.

Manufactured Bane of Humanity: Sarin Gas

Informative Video Presentation regarding Sarin Gas by SciShow

 Sarin gas is one of the deadliest substances in the world. Sarin is an odorless and colorless that is excellent at what it does, and what it does is to kill. It is composed of a phosphorus atom bonded to a fluorine atom, two oxygen atoms, and a methyl group. A methyl group is a carbon atom bonded to three hydrogen atoms. One of the oxygen atoms is bonded to a carbon atom, which is in turn bonded to two methyl groups and another hydrogen atom.

molecular structure of sarin

molecular structure of sarin

Sarin can be made from difluoride methylphosphonate, dichloride methylphosphonate, sodium fluoride, and isopropyl alcohol. The latter two items are easily obtainable, which has perpetuated the erroneous belief that sarin can be made by anyone; in fact, it is extremely difficult to synthesize and is far more likely to kill its creator than it is to kill any potential targets.

But how does sarin actually work? Sarin is a nerve agent and like most nerve agents, it works by inhibiting the function of acetylcholinesterase, or AChE. AChE is an enzyme, meaning its function is to break down other molecules in the body. Specifically, AChE breaks down acetylcholine. Acetylcholine is a neurotransmitter released by the nervous system which binds to muscles’ receptors in order to stimulate activity. AChE then approaches acetylcholine and destroys it to stop muscle activity, breaking the synapses of acetylcholine into inactive fragments. The reason sarin is so devastating is because it combines with the serine in the esterase site of the AChE, rendering the enzyme unreactive. Because the acetylcholine is no longer being broken down by the AChE, acetylcholine remains in the receptor and continuously stimulates the muscles, forcing them to contract uncontrollably. Eventually, the victim is asphyxiated to death after the respiratory system and other muscle-dependent organ system begin to fail.

Diagrams of the specific chemical reactions which occur with nerve agents in the human body

Diagrams of the specific chemical reactions which occur with nerve agents in the human body

sarin diagram 2

Diagram of the specific chemical reactions which occur with nerve agents in the human body

Gerhard Schrader

Gerhard Schrader

 

Sarin gas has had a long history of being used as a chemical weapon even though it was only recently discovered. In fact, it was only synthesized in 1937 by German chemist, Gerhard Schrader, trying to create a stronger, better pesticide, according to The Atlantic. Although it was not used during World War II by the Nazis, it gained its infamous reputation of being one of the most lethal nerve agents. This prompted the production of sarin gas in many countries as a potent instrument of war.

Eventually, in 1993, the Chemical Weapons Conventions (CWC) was ratified, banning the production, stockpiling, and usage of sarin gas and other chemical weapons. This proposal was ratified by 162 countries throughout the globe, with notable exceptions being North Korea and Egypt.

A map showing the countries which signed the Chemical Weapons Conventions. Green indicates that the CWC was signed and ratified while red indicates non-signatory countries.

A map showing the countries which signed the Chemical Weapons Conventions. Green indicates that the CWC was signed and ratified while red indicates non-signatory countries.

However, even though the production and stockpiling of sarin gas is heavily regulated, there still have been sarin gas attacks in the past. According to the New York Times, one of the most gruesome sarin gas attacks was in 1995: a domestic Japanese terrorist group had bombed a Tokyo subway station, killing 8 people and hospitalizing more than 4,700 others. Another recorded incident was in 2013, when the Syrian government fired several rockets filled with sarin gas on rebels and civilians. Due to its ability to kill quickly, painfully and indiscriminately, sarin is considered one of the most heinous weapons that have been created. However, in some senses, sarin is better than other chemical weapons, such as Agent Orange or even napalm, as there are relatively few after effects.

The lethal dose of sarin gas is half a milligram for an average sized person and it takes only 1 to 10 minutes after exposure to die according to the Centers for Disease Control and Prevention. However, there are no after effects if victims are treated properly and victims exposed to small amounts of sarin gas exposure usually recover fairly rapid. On average, survivors usually make a full recovery only after a few weeks. In addition, there are numerous ways to treat sarin gas poisoning, most often atropine, a cheap and generic drug.  Sarin also does not have any chronic environmental effects as the substance breaks down quickly after being introduced to the atmosphere.

molecular structure of atropine

molecular structure of atropine

In spite of this, nearly every country in the world has renounced the use of sarin, and all other nerve gases, as an acceptable military tactic. This is due entirely to the chemistry behind the weapon, as it is the chemical reactions that give rise to the horrific effects of sarin. These chemical reactions cause death in the most graphic way possible; so graphic, in fact, that even the Nazis refused to use sarin in World War II after they developed it. Sarin was outlawed because the chemistry that birthed it was simply too effective, and too gruesome, for the world to handle.

About the Authors: BCABe4 is an Advanced Chemistry Project Group and is focused on understanding the chemistry behind chemical weapons. BCABe4 is composed of Hee-Sung Kim, Sandy Pecht, and Erik Wu. They are all students of the Bergen County Academies and are in the Academy in the Advancement of Science and Technology.