K S Lane is a student of chemistry and is passionate about educating others on her favourite aspects of science.
What Are the Deadliest Chemicals in the World?
The world around us is made up of chemicals. We eat, drink and breathe them every single day of our lives, and most of the time, they’re harmless. They facilitate life. They allow our bodies to function. They make us feel better when we’re sick.
That doesn’t mean, however, that dangerous chemicals don’t exist. Some are poisonous, some cause cancer, some are corrosive and some are volatile. Some chemicals smell so bad that they induce vomiting, and others can set concrete on fire.
This article lists 10 of the most dangerous chemical substances known to man along with some honourable mentions, information about what to do if you are accidentally exposed to a toxic substance and a list of potentially harmful chemicals found in common cleaning products. Read on and be eternally grateful that you didn’t become a chemist!
10. Ethylene Glycol
It’s highly likely that you have a bottle of this first chemical lying around somewhere in your garage. Ethylene glycol, the main ingredient in anti-freeze, is a common household chemical used as a coolant in cars. However, it’s also a dangerous poison.
In the body, it’s converted into glycolaldehyde by the same enzyme that breaks down the alcohol you’d find in beer or wine. Once this occurs, the glycolaldehyde is oxidised into a substance called glycolic acid, which is about as nasty as it sounds. The acid disrupts the body’s delicate pH balance and also has a cytotoxic effect, meaning that it kills cells.
The kidneys and central nervous system are the primary systems that are damaged by the antifreeze chemical. Ethylene glycol didn’t make this list just for its poisonous effects, however. The dangerous chemical also has a notoriously sweet taste, meaning that children, pets and even unwitting adults have been known to guzzle it by mistake and then suffer its negative effects. Talk about a sweet-faced killer!
First Identified: 1856 CE
Chemical Formula: C2H6O2
Where You Might Find it: Computer and automobile coolants, antifreeze, some air conditioning systems
Aside from having a killer name, 2,3,7,8-tetrachlorodibenzo-p-dioxin—often referred to as TCDD or simply dioxin—is a highly toxic compound that can be produced as a byproduct of incomplete combustion (i.e. combustion without enough oxygen present). The chemical causes lesions on the body known as chloracne and damages fatty organs like the liver, spleen and intestines.
This is because dioxin is a fat-soluble molecule and thus has a nasty tendency to accumulate in the body’s fatty tissues and then stick around. One of the scariest things about this chemical is that we don’t really know how it works or why it has such severe effects, which means that treatment for dioxin poisoning is a bit of a guessing game.
First Identified: 1897 CE
Chemical Formula: C12H4Cl4O2
Where You Might Find it: The fat of meat, fish and dairy contaminated via industrial processes
Batrachotoxin, which is found on the skin of certain frogs native to South America, is one of the most potent poisons known to man. It takes just two micrograms per kilogram to be fatal, which means that a fully grown man could be killed by a dose no bigger than a few grains of salt. It’s a neurotoxin, which means that it exerts its effect by preventing neurones from sending electrical messages to one another, causing paralysis and eventually death. Scary stuff!
First Identified: 1960s CE
Chemical Formula: C31H42N2O6
Where You Might Find it: The skin of poison dart frogs
7. Potassium Cyanide
Potassium cyanide is a salt, but it’s about as far from the kind that you'd use to season your fries as possible. It’s incredibly toxic and has gained notoriety for being the choice ingredient in suicide pills for spies and soldiers around the world. The nicest thing that can be said about it is that it offers a quick death.
It disables cellular respiration, the process by which cells make energy, by inhibiting an enzyme that’s essential in ATP production. ATP is the primary energy currency of the body, and the ability to make it is key to, well, living. Within a few minutes of consuming potassium cyanide, victims fall unconscious and then suffer brain death. Yikes!
First Identified: 1752 CE
Chemical Formula: KCN
Where You Might Find it: Ore-processing facilities, some photographic fixers
Thioacetone isn’t poisonous. It isn’t corrosive, explosive or even particularly volatile. However, it has one special property that makes it one of the most dangerous chemicals on earth: its smell. The stench of thioacetone has been described as "fearful," and it causes anyone in its vicinity to vomit, faint or flee with horror.
To get an understanding of just how terrible this smell is, a story is warranted. In 1889, a group of scientists in the German town of Freiburg were working on a related compound and accidentally managed to synthesise some thioacetone. The stench could be detected from half a kilometre away, and it triggered an evacuation of the entire town as people began vomiting uncontrollably. In summation, thioacetone won’t kill you, but it’ll probably make you wish you were dead.
First Identified: 1889 CE
Chemical Formula: C3H6S
Where You Might Find it: Some chemistry labs
Dimethylmercury is a simple little molecule consisting of a central mercury atom bonded to two methyl (CH3) groups. The toxic effects of mercury are known to pretty much everyone, but few are aware that the liquid metal on its own is actually fairly harmless. It can’t bind to any tissues in the body on its own and therefore can’t be absorbed. However, the addition of the two methyl groups in dimethylmercury means that the compound can be readily absorbed into the blood and transported all around the body where it can exert its toxic effect.
The true dangers of working with dimethylmercury came to light in 1996, when chemist Karen Wetterhahn accidentally spilled two drops of the chemical on her glove while working in the lab. Assuming that the latex would prevent the chemical from coming into contact with her skin, she didn’t fret. After a few months, however, she began to exhibit signs of cognitive impairment. Slurred speech, difficulty thinking and fatigue soon gave way to a coma. After five months, her coma finally ended in death.
First Identified: 1858 CE
Chemical Formula: HgC2H6
Where You Might Find it: Reference toxin sets
4. Fluoroantimonic Acid
Fluoroantimonic acid is the strongest acid in the world. Ever head of sulphuric acid? Well, it’s about ten quadrillion times stronger than that. The compound can eat through plastic and glass and could melt the skin from your bones and still be hungry for more.
The only way that it can be stored is in Teflon containers, which are resistant to its corrosive effects. When studying it, scientists aren’t even able to use normal glass beakers unless they dilute it by a factor of thousands. What’s more, fluoroantimonic acid also reacts violently with water. Fun stuff!
First Identified: Not available
Chemical Formula: H2SbF6
Where You Might Find it: Tetraxenon gold compound manufacturing facilities
3. Azidoazide Azide
1-diazidocarbamoyl-5-azidotetrazole, or azidoazide azide, is the most volatile explosive compound currently known to man. It’s comprised of 14 nitrogen atoms loosely bound in a high-energy conformation. When a molecule is in a high-energy conformation, it seeks to move down to a lower energy state, and when this transition occurs, energy is released.
Azidoazide azide is an extreme case of this phenomenon, in which its high energy conformation is so unstable that pretty much anything can make it explode. The slightest pressure or friction, small temperature fluctuations or even exposure to light can cause it to go boom. In fact, it’s so volatile that the normal instruments used to measure how unstable a substance is can’t be used on it. In other words, it’s too explosive to measure how explosive it is. Eeek!
First Identified: Not available
Chemical Formula: C2N14
Where You Might Find it: Almost nowhere, possibly some chemistry labs
2. Chlorine Trifluoride
Chlorine trifluoride, also known as substance N, was discovered by Nazi scientists during the Second World War. The Nazi Party initially intended to have their soldiers use it to melt through Allied bunkers, but after years of research, they determined that it was just too unstable. That’s right, this chemical was too destructive for the Nazis. It’s extremely volatile and will react explosively with just about anything. It’s been known to set fire to glass, sand, rust and, of course, people. It can even cause asbestos—one of the most fire-retardant substances in existence—to catch fire.
The United States briefly tinkered with chlorine trifluoride and attempted to transport a tonne of it in a specialised tanker. This turned out to be a really, really bad move. The tanker crashed and the substance spilled out onto the concrete floor of a warehouse and set fire to it. It ate through the concrete completely along with a good few feet of the dirt and gravel beneath. I don’t know about you, but I don’t want this stuff within a thousand miles of me.
First Identified: 1930s CE
Chemical Formula: ClF3
Where You Might Find it: Rocket propellant, semiconductor cleaner
1. Dimethylcadmium: The Deadliest Chemical in the World?
Even worse than dimethylmercury, dimethylcadmium is considered by many chemists to be the most toxic chemical known to man. Because cadmium is lighter than mercury, the organic compound is more volatile. It absorbs instantly into the bloodstream and rips apart the organs that need the highest supply of blood, including two little body parts that you might have heard of called the heart and the lungs.
If, by some miracle, a person manages to survive the initial exposure, the danger certainly isn’t over. Dimethylcadmium is highly carcinogenic, meaning that it causes cancer. If that isn’t bad enough, it also explodes in water and decomposes into dimethyl calcium peroxide, which is highly explosive. In summation, it’s a volatile, poisonous, cancer-causing, explosive and vicious little molecule that can easily be called the most dangerous chemical known to man. It’s no wonder, really, that the majority of the world’s chemists refuse to work with it.
First Identified: Not available
Chemical Formula: C2H6Cd
Where You Might Find it: Formerly in labs
What to Do If You Are Exposed to a Toxic Chemical
If for any reason you ingest or come into contact with a potentially harmful chemical substance, call 911 (or the emergency services number for your country/state) immediately and request help from medical authorities. For additional help, contact the 24-hour American Association of Poison Control Centers at 1-800-222-1222. If a pet or animal has been exposed, contact the ASPCA National Animal Poison Control Center at 1-888-426-4435.
Harmful and Hazardous Substances That Didn't Make the Top 10
The 10 chemicals above are certainly some of the most toxic, dangerous and harmful around. Many chemists simply refuse to work with one or more of them because of the immense risk they pose to human health. That said, there are many, many more chemical substances in existence that are extremely dangerous but did not quite make the top 10. The following items are listed in alphabetical order rather than according to ranking. Strap on your safety goggles and let's take a look.
Asbestos is a naturally occurring silicate mineral that has been used in construction for centuries due to its ability to insulate and resist heat. Up until the1980s, asbestos was incorporated into many buildings constructed in the United States and elsewhere for its insulative and fire-resistant properties.
Unfortunately, frequent asbestos dust inhalation can have severe consequences on the lungs. The inflammation, scarring and other symptoms resulting from asbestos inhalation even have their own name—asbestosis. Asbestosis is a type of fibrosis that can become quite severe over time and may lead to pulmonary heart disease, cancer, mesothelioma and other potentially lethal complications.
First Identified: 2400 BCE or earlier
Chemical Formula: Mg3Si2O5(OH)4
Where You Might Find it: Homes and buildings constructed prior to 1980
Botulinum toxin is a protein created by certain types of bacteria. Exposure to this protein can cause neurones responsible for muscle movement to malfunction by inhibiting the release an important neurotransmitter. This can result in partial or complete muscle paralysis and may cause death.
Surprisingly, the chemical also has several useful applications. It is used medically to help manage muscle spasms and excessive sweating and in cosmetics to reduce wrinkles. Botox, a popular brand of injections marketed to tighten the skin of the face, derives its name from the first three letters in each of the two words that comprise the protein's name.
First Identified: 1919 CE
Chemical Formula: C6760H10447N1743O2010S32
Where You Might Find it: Tainted canned foods, Botox, hospitals
Carbon monoxide is a flammable gas that exists naturally in our atmosphere in very small amounts. It is also produced by combustion engines in cars and other vehicles and by indoor appliances like ranges and water heaters.
If inhaled, the gas displaces oxygen carried by the hemoglobin in human blood. This can quickly cause vital organs that rely on oxygenated blood—like the heart and brain—to fail. Exposure to carbon monoxide can cause an individual to lose consciousness and die in mere minutes. Worst of all, the gas has no smell or taste and is invisible.
First Identified: 1800 CE
Chemical Formula: CO
Where You Might Find it: Exhaust from engines, stoves, grills, lanterns, furnaces and other devices in which combustion occurs
Formaldehyde is an organic compound that exists naturally in the atmosphere and even in space. While it is a known human carcinogen, it is still commonly used in a wide variety of applications. Formaldehyde has long been a popular embalming agent due to its ability to preserve and fix tissue cells. More commonly, it is used in the production of industrial resins and to strengthen wood, carpet and other materials.
In its gaseous form, the substance can irritate the eyes, nose and throat, and prolonged exposure can lead to leukemia and other varieties of cancer. Ingesting even a small amount of liquid formaldehyde (e.g. embalming fluid) can cause death. Despite this, it occurs naturally in very small amounts in many fruits and vegetables.
First Identified: 1859 CE
Chemical Formula: CH2O
Where You Might Find it: Resin, wood, carpet, embalming fluid, certain foods
Hydrogen Chloride and Hydrochloric Acid (AKA Muriatic Acid)
Hydrochloric acid—a solution consisting of hydrogen chloride and water—is an inorganic chemical system that occurs naturally as a component of the gastric acid humans use to digest food. In the modern day, hydrochloric acid has a number of practical applications. Industrially, it is used to pickle steel in order to prepare it for galvanization and other processes. It is also used on smaller scales to purify salt, process leather and clean collectible mineral specimens.
Despite its many uses, hydrochloric acid is extremely dangerous. As a liquid, it has the potential to damage skin. If ingested, it can corrode the intestines and other internal organs. Acidic mists produced by the solution can damage the eyes, skin and respiratory system.
First Identified: Approximately 800 CE
Chemical Formula: HCl
Where You Might Find it: Drinking water, swimming pools, industrial facilities
Hydrogen Fluoride and Hydrofluoric Acid
Hydrofluoric acid—a solution consisting of hydrogen fluoride and water—is yet another substance that is both extremely dangerous and highly useful. It is typically produced by adding sulfuric acid to fluorite (a common mineral) at a high temperature. Hydrofluoric acid is used in the production of polytetrafluoroethylene (better known as Teflon), a material commonly used to insulate wiring. It is also employed to create compounds used in medicines like fluoxetine (better known as Prozac).
Although less acidic than hydrochloric acid, hydrofluoric acid can cause terrible burns very quickly if it comes in contact with human skin. Inhalation of its vapors can irritate the respiratory system and may result in pulmonary edema, which can be fatal.
First Identified: 1771 CE
Chemical Formula: HF
Where You Might Find it: Teflon, Prozac, glass-etching facilities, oil refineries
Phthalates are man-made substances that are commonly added to plastics to boost their strength and flexibility. Many varieties exist, and since the 1920s, they have been incorporated into a wide variety of plastic products, including food and beverage containers.
Unfortunately, phthalates can act as endocrine disrupters in humans, and their consumption has been linked to a number of serious health problems. Research suggests that phthalates may be associated with recent drops in male fertility, and exposure may also increase risk of diabetes, obesity, breast cancer and other conditions.
First Identified: During the 1920s CE
Chemical Formula: Varies
Where You Might Find it: Shampoo bottles, IV bags, plastic toys, vinyl flooring
Sulfuric acid is a water-soluble chemical that exists naturally in acid rain and near oxidised sulfide minerals. It is also manufactured on a large scale in most of the industrialised world to be used in fertilisers, as a cleaning agent in metal processing, and for industrial purposes.
The acid is highly corrosive and, like some of the other acids listed above, can easily cause chemical burns if it comes in contact with skin. It is labeled a controlled substance by the United Nations, but it is frequently used in the production processes of unregulated illegal narcotics nontheless.
First Identified: Between 850 and 950 CE
Chemical Formula: H2SO4
Where You Might Find it: Acid rain, mine runoff, drain cleaners, fertiliser-manufacturing plants
Cleaning Products and Household Hazards
|Chemical||Products It May Be In|
Some multipurpose, window and kitchen cleaners
Some sink, jewelry and glass cleaners
Some toilet bowl cleaners, scouring powders, laundry whiteners and tap water
Quarternary Ammonium Compounds
Some fabric softeners and antibacterial household cleaners
Some carpet cleaners and dry-cleaning agents
Some fragranced toilet papers, air fresheners, soaps and other products with "fragrance" listed as an ingredient
Some oven cleaners and drain solutions
Some dishwashing detergents and antibacterial hand soaps
Risky Chemicals Are Part of Our World
And there you have it—10 of the most toxic, volatile, corrosive, explosive and all-around dangerous chemicals known to man plus 8 honourable mentions and runners-up. The bright side is that you’ll probably never get within a hundred meters of the most dangerous of these chemicals.
It’s important to remember, however, that in the scheme of human existence, chemistry is still a fairly young discipline. There’s no telling what other terrifying substances scientists will discover (or create) in the coming years. Isn’t that exciting?
Resources and Further Reading
- 2,3,7,8-Tetrachlorodibenzo-P-dioxin. Pubchem. https://pubchem.ncbi.nlm.nih.gov/compound/Tetradioxin
- Asbestos Timeline. (2019, April 17). Mesothelioma Help. https://www.mesotheliomahelp.org/asbestos/history/
- Burke, G. S. (1919, April 5). Notes on Bacillus botulinus. National Society for biotechnological Information. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC378820/?page=1
- Chemical Safety Information-Hydrofluoric Acid. The University of North Carolina. https://ehs.unc.edu/chemical/hfa/chemical-safety-information-hydrofluoric-acid/
- Cosmobiologist. (2015, September 14). Fluoroantimonic Acid: The Strongest Acid Known to Humankind. A Cosmobiologist's Dream. http://cosmobiologist.blogspot.com/2015/09/fluoroantimonic-acid-strongest-acid.html
- Cotton, S. (2012, April 24). Dimethylmercury. Chemistry World. https://www.chemistryworld.com/podcasts/dimethylmercury/3005760.article
- Dioxins and their effects on human health. (2016, October 4). World Health Organization. https://www.who.int/news-room/fact-sheets/detail/dioxins-and-their-effects-on-human-health
- Faletto, J. (2019, August 1). The Stupidly Dangerous Chemical Chlorine Trifluoride Can Make Anything Burst Into Flames on Contact. Discovery. https://www.discovery.com/science/Dangerous-Chemical-Chlorine-Trifluoride
- Grimes, H. (2006). Batrachotoxin. https://people.wou.edu/~courtna/ch350/Projects_2006/Grimes/index.html
- Hayat, M. A. (2014). Autophagy: Cancer, Other Pathologies, Inflammation, Immunity, Infection, and Aging. Science Direct. https://www.sciencedirect.com/book/9780124055308/autophagy-cancer-other-pathologies-inflammation-immunity-infection-and-aging
- The History of Formaldehyde. Formacare. https://www.formacare.eu/about-formaldehyde/history-of-formaldehyde/
- Inglis-Arkell, E. (2015, May 19). This Is The World's Smelliest Chemical. iO9 Gizmodo. https://io9.gizmodo.com/this-is-the-worlds-smelliest-chemical-1705413119?IR=T
- Lowe, D. (2013, January 9). Things I Won’t Work With: Azidoazide Azides, More Or Less. Science. https://blogs.sciencemag.org/pipeline/archives/2013/01/09/things_i_wont_work_with_azidoazide_azides_more_or_less
- Medical Management Guidelines for Formaldehyde. (2014, October 21). Agency for Toxic Substances and Disease Registry. https://www.atsdr.cdc.gov/mmg/mmg.asp?id=216&tid=39
- Phthalates. Assembly of First Nations. https://www.afn.ca/uploads/files/env/phthalates.pdf
- Phthalates: The Everywhere Chemical. National Institute for Environmental Health Sciences. https://www.niehs.nih.gov/research/supported/assets/docs/j_q/phthalates_the_everywhere_chemical_handout_508.pdf
- Public Health Statement for Sulfur Trioxide and Sulfuric Acid. Agency for Toxic Substances and Disease Registry. (2015, January 21). https://www.atsdr.cdc.gov/phs/phs.asp?id=254&tid=47
- Rosenberg, J. Asbestos Cover-Up. Asbestos.com. https://www.asbestos.com/featured-stories/cover-up/
- Schechner, S. (2004, December 13). What Is Dioxin, Anyway? Slate. https://slate.com/news-and-politics/2004/12/what-is-dioxin-anyway.html
- Scholl, J. (2011, October). 8 Hidden Toxins: What’s Lurking in Your Cleaning Products? Experience L!fe. https://experiencelife.com/article/8-hidden-toxins-whats-lurking-in-your-cleaning-products/
© 2018 K S Lane
jaseanth on July 01, 2020:
very very useful
George Xu from Philippines on May 27, 2020:
What about Toluene diisocyanate [TDI], the precursor in manufacturing polyurethane for foams? Defintely toxic as well.
Pt 123 on November 21, 2019:
These chemicals are creepy
Pamela Oglesby from Sunny Florida on November 20, 2018:
There are sure some chemicals in this list that are really scary. I don't want to be near them. There are many interesting facs in this article.