Monday, September 23, 2013

Küresel İklim Krizini Takip Et.


(Küresel iklim krizi - güncel gelişmeler 7)



Neden Kimse Küresel Isınmadan Bahsetmiyor?


Küresel iklim değişimi, gündemin en önemli başlıklarından biri olması gerekirken, hakkındaki bilimsel uzlaşmayla hiç de uyuşmacak bir biçimde unutuluyor, unutturuluyor.

Çok tuhaf. Sadece birkaç haber başlığını alt alta yazmak bile insanın öfkeden deliye dönmesine yetmeliyken, iklim haberlerinin hem sıklığı hem de içeriği azalıyor. Atmosferdeki karbondioksit miktarı 400 ppm'i daha yeni aşmışken1, dünyada varolan bitki türlerinin yarısı ve hayvan türlerinin üçte biri 2080 yılına kadar yaşam alanlarının yarı yarıya azalması tehlikesi ile karşı karşıyayken ve insan kaynaklı iklim değişiminin türler üzerindeki baskısının evrimden 10.000 kat daha hızlı olduğu ortaya konmuşken, ne televizyonların ne de holding gazetelerinin Başbakan'ın laflarından başka manşet atmıyor olmalarında bir tuhaflık yok mu sizce de?2 Hele ki Türkiye'nin sera gazları geometrik olarak artmaya devam ederken...



Küresel ısınmayı önemseyen ancak Türkiye'deki gündemin telaşesinden iklim gündemine yetişemeyenler için, iki yıldır düzenli olarak yaptığımız gibi, geçtiğimiz dört ayda (Nisan, Mayıs, Haziran ve Temmuz ayları) olup bitenleri özetlemek ve hatırlatmak istedik. Daha temel iklim bilgileri için, Climate Reality Project'in hazırladığı kısa videoları izleyebilirsiniz.

Öncelikle, boş işlerle uğraşmıyoruz: İklimle ilgili makalelerin %97'si kürenin ısındığı ve bunun sebebinin insan faaliyetleri olduğu konusunda anlaşıyor.3 Öyle ki, geçtiğimiz Nisan ayında, NASA Goddard Enstitüsü'nün başındaki James Hansen iklim politikalarına daha fazla zaman ayırabilmek için görevinden istifa etti.

İnsan kaynaklı küresel ısınma hakkında görüş beyan eden iklim makalelerinin %97'si küresel ısınmanın gerçekleştiği ve sebebinin biz olduğumuz konusunda hemfikir.


Kemerlerinizi bağlayın, küresel iklim değişiminin insanı dehşete düşüren dünyasında kısa bir tura başlıyoruz.


İklim Gündeminden, Gözünüze Çarpmamış Olanlar


Antarktika'daki buzullara ne olduğunu tam olarak kestiremiyoruz; bir araştırma rekor hızda erime tespit ederken başka bir araştırma Güney Kutbu'nun soğuyor olabileceğini belirtiyor. Kuzey Kutbu'yla ilgili ise böyle bir belirsizlik yok; bu kış Kuzey Buz Denizi'nin en düşük beşinci buz kütlesi kaydedilirken, bazı uzmanlar Kuzey Kutbu'nda hiç buzun kalmayacağı yazların 2050'den önce gelebileceğini ifade ediyorlar. Bunun müthiş miktarda metanın serbest kalmasına yol açabileceği düşünülüyor. Benzer haberler dağ zirvelerinden geliyor: Everest dağının buzulları her geçen yıl daha hızlı azalıyor, Şili'de And dağlarının buzulları da son otuz yılda yüzde 30-50 oranında azaldı. Üstelik, 2003-2009 yılları arasında eriyen dağ buzullarının deniz seviyesindeki artışa etkisinin kutup buzullarının etkisine eşit olduğu hesaplanıyor. Buzulların erimesi yüzünden Alaska'da ABD'nin ilk iklim ilticası yaşanıyor.

Sandy kasırgasının sel suları  New York'ta Hoboken PATH istasyonunun asansör şaftından içeri doluyor.
Fotoğraf: Reuters/Port Authority Trans-Hudson

Eriyen buzullar sebebiyle (ve ısınan denizler sebebiyle, Amerika'nın kuzeybatısındaki gibi örneğin) ciddi ölçüde bozulan su döngüsüyle fırtına (örneğin büyük yıkıma yol açan Sandy ve Barbara kasırgaları) ve aşırı yağış haberleri geliyor.4 Su döngüsünün bozulması aynı zamanda kuraklığa da yol açıyor. Brezilya'dan Avusturalya'ya kadar birçok yerden aşırı sıcak ve kuraklık haberleri geliyor. Nitekim, Birleşmiş Milletler'e bağlı Dünya Meteoroloji Örgütü de, geçtiğimiz on yılda, eşi benzeri görülmemiş miktarda aşırı iklim olayına tanıklık ettiğimizi vurguluyor.


Dünya son 1400 yılda hiç olmadığı kadar hızlı ısınıyor, hem de bu ısınma – tam iklim modellerinin tahmin ettiği gibi – yüzey sıcaklığını her yerde eşitleyecek şekilde gerçekleşiyor. Ancak dünya, türlerin uyum sağlaması için fazla hızlı ısınıyor. Balıklar yüksek enlemlere doğru ilerlerken Kuzey Buz Denizi hızla asitleniyor.

Tüm bunlar, şu anda yaşadıklarımız. Bizi nelerin beklediğine göz atmadan önce, the International Displacement Monitoring Centre and Norwegian Refugee Council tarafından hazırlanan, 2012 yılında afetler sebebiyle yerinden edilenlerin gösterildiği haritayı incelemenizi öneririz.

2012'de afet sebebiyle yerinden edilmeler.
Pembe: Yeni yerinden olma gerçekleşen ülkeler
Kırmızı: 50 binden fazla kişinin yerinden olduğu ülkeler
Siyah çizgi: Nüfusun %1'inden fazlasının yerinden olduğu ülkeler


Holding Gazetelerini Okursanız Gelecekte Gözünüze Çarpamayacak Olanlar


Küresel ısınmanın beklenen etkileri” deyince hep aklımıza geldiği gibi, hangi türlerin nasıl zarar göreceğinden bahsedebiliriz. En son araştırmaların değindiği üzere, koalaların yaşam alanlarının daraldığından, Güney Avusturalya'da yunus ölümlerinden, kutup ayılarını etkilemeye başlayan patojenlerden, ısınma sebebiyle dişi oranı artan renkli kaplumbağalardan, kör kalan aç çitalardan ve küresel ısınmanın etkisinin yeni fark edildiği onlarca türden bahsedebiliriz.


Ormanlık bitki örtüsüne çarparak bir gözünü kaybeden çita, Namibya.
Fotoğraf: The AfriCat Foundation

Ya da, “börtü böceğin” insanlığın geleceğiyle ilişkisini kuramayanlar için, doğrudan doğruya deniz seviyesindeki artışlar sebebiyle Küba'da binlerce binanın sular altında kalırken Finlandiya sahil şeridinin ciddi ölçüde değişeceğinden, kasırgaların şiddet ve sıklığının artacağından, şarap üretiminin tehlike altına girmekte olduğundan, sıtmanın İngiltere'ye kadar ulaşma ihtimalinin oluştuğundan, New York'ta sıcak hava dalgalarına bağlı ölümlerin %22 artmasının beklendiğinden, Pakistan'da sıcak hava dalgalarının daha da şiddetleneceğinden ve Havai'de hem daha az yağış hem de daha çok hortum yaşanacağı gibi şaşırtıcı araştırmalardan bahsedebiliriz.

Tüm yukarıdakilerin iklim açısından çok önemli olduğunu düşünüyoruz.5 Yine de, bu yazıda özellikle öne çıkarmayı uygun bulduğumuz birkaç husus var:




Vurgulayalım: Küresel iklim krizi kapıda değil, kapıyı zorluyor da değil. Küresel iklim krizini şu anda yaşamaktayız. Bu kriz her geçen gün derinleşiyor ve daha da derinleşmesi bekleniyor. Hükümetler finansal krizi bahane ederek karbon salımı konusunda taahhüt vermekten kaçınırken, araştırmalar çok radikal adımlar atılması gerektiğini gösteriyor.

Hükümetlerarası İklim Değişikliği Paneli (IPCC) en son raporunu yayınlamaya 27 Eylül'de başlayacak. Bir bilimsel raporun insanları sokaklara döktüğü görülmüş şey değil, ama şu son zamanlarda sokaklarda, parklarda ve meydanlarda, şimdiye kadar hiç görülmemiş birçok şey de olmuyor değil hani.





1 Atmosferdeki karbondioksit seviyesinin 400 ppm'i aşması, 399 ppm'i aşmasından daha önemli değil elbette, ama durumun aciliyetini hatırlamak için iyi bir fırsat olabilir. Guardian'ın hazırladığı interaktif haberi incelemeden geçmeyin.

2 Daha kötüsü de var. Wall Street Journal'da yayınlanan “In Defense of Carbon Dioxide” başlıklı yazıdaki saçmalıklar bir yana, iklim inkarcılarının fonladığı Heartland Enstitüsü Çin'in iklim değişimi konusunda şüpheci olduğu gibi ipe sapa gelmez bir iddia yayınladı.

3 Aman dikkat: Bu konuda Wall Street Journal'da “Science Is About Evidence, Not Consensus” başlıklı bir yorum yayınladı. Bu yorum hakemli bilimsel makalelere referans vermediği gibi, küresel ısınmanın temel birkaç fenomenini de yanlış anlamakta ısrar ediyor.

4 Guardian'dan Homa Khaleeli ve Emine Saner, üst üste gelecek on yağmurlu yazın yol açacağı 40 şeyi listelemişler.

5Bunlara, görece daha az önemli olduğunu düşündüğümüz şu araştırmayı da ekleyelim: Hava akımlarındaki düzensizleşmeyle beraber uçak yolculuklarında türbülansın da artacağı öngörülüyor.


6Kiribati'nin yaşadıklarıyla ilgili fotoğraf galerisine bağlantıdan ulaşabilirsiniz.

Thursday, September 12, 2013

What's in the menu for your uprising: Chemical weapons and effects of tear gas – Çağrı Mert Bakırcı



Riot control methods: What's in your riot's menu? How to deal with them? - Çağrı Mert Bakırcı part 4.


The Turkish original of this article, “İsyan Kontrolünde Kullanılan Yöntemler ve Biyolojik Etkileri”, signed Çağrı Mert Bakırcı, was published on June 16th, 2013 in Evrim Ağacı.org. The content of the article is as follows: Introduction, The chemicals used in riot control and their biological effects, Pressurized water, Water cannon, Armed vehicles, Scent-based weapons, Pepper gas, Tear gas and its varieties, The expiration dates of gases and their effects, Why we feel that the effect of the gases change/increase, How to protect oneself, Batons, Conclusion.


We partitioned the article and therefore restructured the sections for presentational purposes. The first part covered batons and pressurized water while the second covered water cannons and other armed vehicles. This will be an extension of the third part on scent-based weapons, pepper gas, tear gas and its varieties. We will discuss
  • lethal chemical weapons,
  • the issue of expiration date, and
  • the development of the effects of gases.




Some lethal chemical weapons


In addition to tear gas varieties discussed in the previous part [LINK LINK LINK] of this article, there are much more dangerous chemical weapons used throughout history.


  • Rainbow Herbicides


First, we will study the Rainbow Herbicides used by the US military in Southeast Asia during the Vietnam War. The 8 varieties, each produced for a different purpose, are strictly forbidden internationally. The objective in their utilization was destroying the plant-based ecosystem of an agricultural food production and/or destroying foliage which provides the enemy cover.


Agent Pink and Agent Green contain large amounts of TCDD and were only used in the early “testing” stages of the spraying program before 1964. Agent Purple, designed to clear brush, was also used in the same period. Agent Blue, aimed at killing narrow leaf plants (such as rice, grass, banana and bamboo), and Agent White were used extensively (around 75 and 20 million liters, respectively) in Vietnam and are still used in industrial agriculture complexes.


A total of 76 million liters of Agent Orange were sprayed to Vietnam, Laos and Cambodia during Vietnam War, causing 500 000 children to be born with birth defects, killing 400 000 people, and affecting more than 1 million people. The official goal of the US army was, according to the Wikipedia article on Agent Orange, “to defoliate forested and rural land, depriving guerrillas of cover; [… and] destroy the ability of peasants to support themselves in the countryside and forcing them to flee to the U.S. dominated cities, thus depriving the guerrillas of their rural support and food supply.”


Below are some photos of how the Agent Orange was sprayed.








Note that the names of these chemicals indicate the color of stripes on their containers and not the color of the gas sprayed.


The Rainbow Herbicides, Agent Orange especially, are highly toxic. Their health effects include throat cancer, acute/chronic leukemia, Hodgkin's lymphoma, lung cancer, prostate cancer, soft tissue sarcoma, colon cancer, as well as nerve, digestive, skin and respiratory disorders. In many countries, not only their usage but also to keep them is strictly forbidden.


Agent Orange is not designed for riot control and is therefore not used via capsules as the OC, CS, CR and CN, the tear gas varieties used by the police as we mentioned in the previous part. They are sprayed by aircrafts, as seen in the photos above. No canisters or capsules for Agent Orange were observed until now anywhere in the world.


Agent Orange contains high amounts of dioxin and specifically TCDD, one of the most dangerous chemical weapons. Once again, it is not and cannot be used for riot control.


In short, the use of Agent Orange is not a game. Access to it is strongly restricted and its use is strictly forbidden. It is nearly impossible that it was used by police forces during the uprising in Turkey. Some photos of its effects may help you understand what we mean:






  • Phosgene and Diphosgene: They were used in World War I and in the 2nd Sino-Japanese War. Known to be lethal, their use is strongly restricted by law.


  • Mustard gas (Sulfur mustard): According to the Wikipedia article on Sulfur mustard, they have “the ability to form large blisters on the exposed skin and in the lungs. Pure sulfur mustards are colorless, viscous liquids at room temperature. When used in impure form, such as warfare agents, they are usually yellow-brown in color and have an odor resembling mustard plants, garlic, or horseradish, hence the name.” It affects the guanine in the DNA, prevents cellular division and leads to programmed cell death. Its use is regulated under the 1993 Chemical Weapons Convention.


  • Nerve agents: They are a class of phosphorus- containing organic chemicals that are known to be lethal. United Nations considers them as weapons of mass destruction, and they are therefore not used in riot control.




Dates of Expiry of the Gases


One of the frequently asked questions was whether there are problems due to exposure to gases whose expiry dates passed. Unfortunately, it is not known whether expired gases have additional health hazards or not. This uncertainty itself is sufficient reason for not using expired gases. Although future research may as well show that it is biologically or chemically irrelevant, assuming this probability can be dangerous and police forces should not make such risky presuppositions.


It was observed (in India, Cairo, Jordan and Greece) that gases which are expired by more than 30 years were used by police forces. Interviewed experts on the subject matter stated (for instance in Al-Masry Al-Youm newspaper) that long exposure to expired gases may harm more severely than normal gases. However, this information does not seem to rely on research, and a more established opinion on the subject cannot be reached until further studies.


While some claim that expired gases have less effects (and that therefore they should be used before the expiry date to obtain full effectiveness), others argue that long waited gases may become more harmful and cause uncontrolled effects. According to some doctors, long waited gases may lead to unexpected side effects.


One can say that the chemicals used in tear gas are unstable compounds and they dissolve after some time. The resulting chemicals may be harmful to body, or maybe harmless. Still, a direct consequence is that the tearing effect is reduced in this way. In short, further research is needed to reach a solid conclusion on this subject.




Why Do We Feel That The Effects Are Increasing/Changing?


During the uprising in Turkey, many protesters experienced that the effects of the chemicals changed and increased. This phenomenon was observed in many other riots that had long durations. As a result, several speculations follow and various wrong news items spread, claiming the use of chemicals that may not be used (nor kept) or that are not produced anymore.


We should know that the chemicals used against the protests have not changed. For instance, during the Gezi resistance, the chemicals used were always OC, CS and perhaps CR (although we did not find any evidence of its use yet). [See Part 3 of this article.] These are non-lethal chemical weapons routinely used in various countries.


There are two main reasons for the protesters to feel an increase in the effects. First, extensive and long-duration use of chemicals have a cumulative effect and thus cause different reaction in the body. As this is not felt by a single individual but by a large group of people at the same time, the protesters may conclude that a different type of gas is used. However, what changes is not the gas but the effects of the same gas (OC, CS or CR). In other words, repetitive exposure to the same chemical may cause different physical reactions. The reason for many people to feel the change simultaneously is as follows: The thresholds for the receptors and nerves affected by these chemicals are at similar levels for all human beings. Therefore, after a certain dose, there is a simultaneous reaction to the gases in many individuals, such as pain and inflammation.


All this applies to the gas bombs shot in canisters (as their content is fixed and cannot be changed after the production). The second reason, on the other hand, relates to water cannons and the chemicals mixed with water sprayed from them. Contrary to common belief, the liquid sprayed by a water cannon is not pure water. As mentioned before, micro-particles can be added to increase friction, and tear gas can be added too. When the amount of tear gas compounds is increased in the mixture, its effect on the body increases. Moreover, as opposed to being exposed to gas, these mixtures directly affect the skin and therefore have a stronger effect. (Furthermore, the CR gas – if used – is much more effective in wet parts.) So, when the security forces increase the amount of chemicals in the mixture, their effects increase and the physical reaction of the protester's body may change.


To sum up, an increase in pain due to chemicals does not necessarily imply a change in the chemicals. Increased use of the same chemical would give the same result. While the gases in chemicals cannot be altered (they are bought as they are), the chemical concentrations in the water cannons may vary. The police forces should take special care about this as chemically dense mixtures may cause permanent damages and even death.


There is a particularly important issue on this subject: Contrary to the gases bought in canisters, the chemicals used in the water cannons are hard to identify. Hence, it is crucial to analyze the liquid mixtures in order to understand their actual content. To this end, you can keep your clothes that are exposed to them and let them analyzed in labs with a lawyer's help.


However, it is also useful to avoid misinformation on this subject. It is wrong and misleading to claim (without evidence) that the police used unknown gases and chemicals, just to prove the legitimacy of the protests. The “normal” gases already classify as chemical weapons and their exaggerated use in the Gezi protests is already horrifying for any sane person who could imagine its consequences. Therefore, what is needed is to emphasize the already existing error and crime, instead of speculating and producing unverified information. In any case, the use of tear gases in riot control is very dangerous for public health and should be stopped immediately.




How To Protect Ourselves


Editorial note: The original article suggests the followings: Avoid contact. Be prepared. Remain outdoors. Blink your eyes and wash them with water. Take off your clothes. Use cold water and neutralizing chemicals. Use soap and water after some time. Get medical help. Help the animals around you.
In order to avoid repetition, we skip this section and refer our readers to the following articles we already translated in the past:




Conclusion


While there is no effective way of getting rid of these gases and chemicals, the most convenient way would be the prohibition and restriction of their uses. These chemicals can be lethal, especially when their dose is increased. While their effects can be reduced by using other neutralizing chemicals, the individuals exposed to them would experience middle-term and long-term effects of them. Therefore, the protesters are advised to get medical support as soon as they can, when they are exposed to these gases.


It should be kept in mind that the 1925 Geneva Protocol bans the use of lethal biological and chemical weapons and Turkey signed this protocol. Hence, governments around world should act responsibly when using chemicals in riot control. Otherwise, they would be acceding that they aim at murdering their own people.






Follow-up: It is now documented that the police used chemicals in Adana during the uprising. Chemical analysis showed that the water mixture used by the water cannons contained dihydrocapsaicin, which is known to have lethal effects.




Monday, September 9, 2013

What's in the menu for your uprising: Scent-based weapons, Pepper gas, Tear gas – Çağrı Mert Bakırcı



Riot control methods: What's in your riot's menu? How to deal with them? - Çağrı Mert Bakırcı part 3.


The Turkish original of this article, “İsyan Kontrolünde Kullanılan Yöntemler ve Biyolojik Etkileri”, signed Çağrı Mert Bakırcı, was published on June 16th, 2013 in Evrim Ağacı.org. The content of the article is as follows: Introduction, The chemicals used in riot control and their biological effects, Pressurized water, Water cannon, Armed vehicles, Scent-based weapons, Pepper gas, Tear gas and its varieties, The expiration dates of gases and their effects, Why we feel that the effect of the gases change/increase, How to protect oneself, Batons, Conclusion.


We divided the article into parts and therefore restructured the sections for presentational purposes. The first part covered batons and pressurized water while the second covered water cannons and other armed vehicles. We will now discuss
  • scent-based weapons,
  • pepper gas, and
  • tear gas varieties.


Scent-based weapons


While they are used rather infrequently, scent-based weapons serve as an important example of non-lethal weapons. The malodorants, sprayed from water cannons, leave a terrible odor in the affected area and do not wash off easily. As a result the individuals feel like vomiting and cannot focus on the protest. Sometimes the toxicity of these chemicals can be so overly high that they can cause permanent damage.


As an example, Israel used them for crowd control in September 2008. (See photo below.)



Pepper Spray




Pepper spray, also known as OC spray (from "Oleoresin Capsicum"), OC gas, and capsicum spray, is a lachrymatory agent (a chemical compound that irritates the eyes to cause tears, pain, and temporary blindness) used in policing, riot control, crowd control, and personal self-defense, including defense against dogs and bears. Its inflammatory effects cause the eyes to close, taking away vision. This temporary blindness allows officers to more easily restrain subjects and permits persons using pepper spray for self-defense an opportunity to escape. Although considered a less-than-lethal agent, it has been deadly in rare cases, and concerns have been raised about a number of deaths where being pepper sprayed may have been a contributing factor.

The active ingredient in pepper spray is capsaicin, which is a chemical derived from the fruit of plants in the Capsicum genus, including chilis.”


This gas can be in different colors, depending on the amount of pepper and other additional chemicals constituting it. While the more common color is a grayish white, it can also be orange, brownish orange or yellowish orange. Sometimes colorants are added on purpose in order to block sight or paint the protesters.


Pepper gas is either sprayed from canisters or fired from a paintball gun. In the case of firing from a gun, its effect from short range is quite similar to actual guns. Hence, it is required that it is fired with an angle of 45 degrees to the ground. As the capsule is hot and fast, when fired from short distances, it causes burns, disruptions and serious brain/sight damages.




Pepper spray is an inflammatory agent. It causes immediate closing of the eyes, difficulty breathing, runny nose, and coughing. The duration of its effects depends on the strength of the spray but the average full effect lasts around thirty to forty-five minutes, with diminished effects lasting for hours.

The Journal of Investigative Ophthalmology and Visual Science published a study that concluded that single exposure of the eye to OC is harmless, but repeated exposure can result in long-lasting changes in corneal sensitivity. They found no lasting decrease in visual acuity.

The European Parliament Scientific and Technological Options Assessment (STOA) published in 1998 "An Appraisal of Technologies of Political Control" with extensive information on pepper spray and tear gas. They write:

The effects of pepper spray are far more severe, including temporary blindness which lasts from 15–30 minutes, a burning sensation of the skin which lasts from 45 to 60 minutes, upper body spasms which force a person to bend forward and uncontrollable coughing making it difficult to breathe or speak for between 3 to 15 minutes. …

“… Direct close-range spray can cause more serious eye irritation by attacking the cornea with a concentrated stream of liquid (the so-called "hydraulic needle" effect). Some brands have addressed this problem by means of an elliptically cone-shaped spray pattern.



“Capsaicin is not soluble in water, and even large volumes of water will not wash it off. In general, victims are encouraged to blink vigorously in order to encourage tears, which will help flush the irritant from the eyes.

A formal study of five often-recommended treatments for skin pain (Maalox, 2% lidocaine gel, baby shampoo, milk, or water) concluded that:

"...there was no significant difference in pain relief provided by five different treatment regimens. Time after exposure appeared to be the best predictor for decrease in pain..."


Contact with liquid seems to have a relaxing effect, but there are no reports showing pain relief. In any case, the fluidity is considered to slightly reduce the pain caused by the pepper gas. Many ambulance services and emergency departments use baby shampoo to remove the spray. In general, the time for recovery can be reduced to 7-15 minutes with these extra treatments.




Tear Gas (Lachrymatory agent)


As the Wikipedia article on Tear Gas states, research shows that the use of tear gas has some serious risks:


As with all non-lethal, or less-than-lethal weapons, there is some risk of serious permanent injury or death when tear gas is used. This includes risks from being hit by tear gas cartridges, which include severe bruising, loss of eyes, skull fracture, and even death. While the medical consequences of the gases themselves are typically limited to minor skin inflammation, delayed complications are also possible: people with pre-existing respiratory conditions such as asthma, who are particularly at risk, may sometimes require hospitalization or even ventilation support. Skin exposure to CS may cause chemical burns or induce allergic contact dermatitis. When people are hit at close range or are severely exposed, eye injuries involving scarring of the cornea can lead to a permanent loss in visual acuity.”


There are several types of tear gas:


  • OC (Pepper spray) : See previous section.

  • CS gas (2-chlorobenzalmalononitrile) : A capsule used in Istanbul during the uprising in 2013 can be seen below. While considered non-lethal, many studies have raised doubts to this classification by showing that it can cause pulmonary damage as well as damage to the heart and liver. Being exposed to CS gas indoors can significantly contribute to or even cause lethal effects. CS gas exposure is further correlated to miscarriages. As the Wikipedia article on CS gas states, according to studies, “CS contamination can be removed by washing with an alkaline solution of water and 5% sodium bisulfite." The color of CS gas is typically light orange.

  • CR gas (dibenzoxazepine) : CR is a pale yellow solid with a pepper-like odor. As it is slightly soluble in water, its effects are not reduced when treated with water. It is usually fired in canisters that heat up, producing an aerosol cloud. According to the Wikipedia article on CR gas,

    Its effects are approximately 6 to 10 times more powerful than those of CS gas. CR causes intense skin irritation, in particular around moist areas; blepharospasm, causing temporary blindness; and coughing, gasping for breath, and panic. It is capable of causing immediate incapacitation. It is a suspected carcinogen. It is toxic, but less so than CS gas, by ingestion and exposure. However, it can be lethal in large quantities. In a poorly ventilated space, an individual may inhale a lethal dose within minutes. Death is caused by asphyxiation and pulmonary edema.

    “The effect of CR is long-term and persistent. CR can persist on surfaces, especially porous ones, for up to 60 days.

    “While CS can be decontaminated with a large amount of water, use of water may exacerbate the effects of CR. Skin contaminated with CR gas may become extremely painful in contact with water for up to 48 hours after contamination.”

    The following video, “CR gas human test”, shows the effects of CR gas:



CR gas is known to be commonly used in Ukraine, Israel and Egypt.


  • CN gas (Phenacyl chloride) : According to the Wikipedia article on CN gas, “Because of its significantly greater toxicity, it has largely been supplanted by CS gas. Even though CN is still supplied to paramilitary and police forces in a small pressurized aerosol known as “Mace” or tear gas, its use is falling as pepper spray both works and disperses more quickly than CN.” A capsule can be seen below.



  • Nonivamide (pelargonic acid vanillylamide or PAVA) is a pepper gas derivative, more heat-stable than capsaicin. It is typically used as an active ingredient in pepper sprays.

  • BA (Bromoacetone): Bromoacetone is a colorless liquid used in World War I as a chemical weapon. It is highly toxic and is therefore not used in riot control.

  • Xylyl bromide (Methylbenzyl bromide or T-stoff): Also used as a chemical weapon in World War I but not in use for riot control, it is a colorless liquid with a pleasant aromatic smell.

  • syn-Propanethial-S-oxide: This is the chemical released from onions as they are sliced. In general, it is not used as a tear gas ingredient. Yet, we would like to keep it in our list as it has similar effects.