Timeline of chemical risk

This is a timeline of chemical risk, which encompasses the potential harm from exposure to hazardous chemicals, whether from intentional or unintentional sources. Unintentional chemical risks arise from accidents, spills, or mishandling of chemicals, leading to exposure that can affect human health, the environment, and property. Intentional chemical risks include those posed by chemical terrorism or warfare, where hazardous substances are deliberately used to cause harm or disruption. Managing chemical risk involves assessing the toxicity of substances, exposure routes, and implementing safety measures and emergency protocols to mitigate both accidental and deliberate threats.

Sample questions

The following are some interesting questions that can be answered by reading this timeline:

• What chemical agents are mentioned in the timeline?
  • Sort the full timeline by "Agent".
  • You will see a compiled list of chemical agents, including metals, industrial chemicals, pesticides, nerve agents, and environmental pollutants.
• When were major toxic or dangerous chemicals first discovered or identified?
  • Sort the full timeline by "Event type" and look for the group of rows with value "Chemical hazard identification".
  • You will receive a chronological list of notable events in which chemical hazards were identified unintentionally.
• What are the major industrial accidents involving hazardous chemicals that have occurred globally since the mid-20th century?
  • Sort the full timeline by "Event type" and look for the group of rows with value "Industrial accident".
  • You will see a timeline of major global industrial accidents involving hazardous chemicals. Events include deadly explosions, toxic gas leaks, and chemical spills from 1947 to 2020, such as the Bhopal disaster, Seveso accident, and Beirut explosion, highlighting environmental damage, mass casualties, and failures in industrial safety and regulation.
• What are some notable chemical warfare production facilities?
  • Sort the full timeline by "Event type" and look for the group of rows with value "Facility".
  • You will mostly see a list of significant chemical warfare-related facilities created by the U.S. military during the Cold War.
• What international treaties or policies have addressed the regulation or prevention of chemical hazards?
  • Sort the full timeline by "Event type" and look for the group of rows with value "International policy".
  • You will see a list of international policy events addressing chemical risk, including treaties, regulations, and organizational guidelines.
• What are some major literary works that played a role in shaping awareness of chemical hazards?
  • Sort the full timeline by "Event type" and look for the group of rows with value "Literature".
  • You will receive a chronological list of influential publications that raised awareness of chemical risks.
• Other events are described under the following types: "Agricultural chemical crisis", "Bioweapon testing", "Chemical weapon deployment", "Industrial toxic exposure", "National policy", "Terrorist attack", "Terrorist chemical research", and "Wartime chemical research".

Big picture

Time period	Development summary	More details
Ancient Times–18th Century	Early awareness and traditional hazards	Human exposure to chemical risks dates back to antiquity, with early societies recognizing the dangers of substances like lead, mercury, and arsenic. Ancient Egyptians and Romans document occupational hazards, particularly in mining and metallurgy. Hippocrates and Pliny the Elder note the health effects of toxic fumes, while Paracelsus introduces the principle of dose-dependent toxicity. Alchemists and early chemists often suffer poisoning due to limited safety knowledge. By the 18th century, industrialization increases exposure to hazardous chemicals, but scientific understanding remained rudimentary. While some preventive measures exist, such as protective masks for miners, chemical risk is largely an empirical concept rather than a formalized field of study.
19th–Mid-20th Century	Industrialization and emergence of toxicology	The Industrial Revolution greatly expands chemical production, leading to widespread occupational and environmental hazards. The rise of synthetic chemicals in dyes, pesticides, and pharmaceuticals introduces new risks, often identified through accidental poisonings. Pioneering studies, such as those by Mathieu Orfila (father of toxicology), lay the foundation for systematic risk assessment. Workplace safety regulations emerge in the late 19th century, particularly in Europe and the United States, as industrial accidents and chemical-related diseases gained public attention. The mid-20th century sees major environmental disasters, such as mercury poisoning in Minamata, Japan, and pesticide contamination highlighted in Rachel Carson’s Silent Spring (1962). These events catalyze the development of regulatory frameworks and public awareness of chemical hazards.
Mid-20th Century–1990s	Regulation and risk management	Growing recognition of chemical risks leads to the establishment of formal regulatory agencies and international safety standards. The 1970s see the creation of the U.S. Environmental Protection Agency (EPA), tasked with overseeing chemical safety. Landmark policies, such as the Clean Air Act (1970) and the Toxic Substances Control Act (1976), seek to limit exposure to hazardous chemicals. Industrial hygiene and risk assessment methodologies advanced, incorporating epidemiology and exposure modeling. Major disasters, including the Bhopal gas tragedy (1984) and Chernobyl nuclear accident (1986), reinforce the need for stricter controls. By the 1990s, chemical risk management would become a structured discipline, integrating occupational health, environmental science, and public policy.
2000s–present	Modern challenges and emerging risks	Contemporary chemical risk management focuses on emerging threats such as endocrine disruptors, microplastics, and nanomaterials, whose long-term effects remain uncertain. Advances in computational toxicology and machine learning enhance predictive models for chemical safety. Global initiatives, including the REACH regulation (2006) in the European Union and the Stockholm Convention on Persistent Organic Pollutants, aim to minimize exposure to hazardous substances. Public concern over climate change and industrial pollution drive stricter environmental regulations and the development of green chemistry. However, challenges remain, particularly in regulating novel synthetic compounds, addressing disparities in chemical safety across nations, and managing the unintended consequences of new technologies. The future of chemical risk lies in balancing innovation with sustainable, precautionary approaches.

Summary by decade

Time period	Development summary	More details
1920s	Toxic expansion	The decade witnesses the extensive use of lead-based paints, which are common in households and public buildings. At this time, the toxicity of lead and its effects on health, especially in children, are not well known, and its use persists. Additionally, the rise of synthetic chemicals in industrial processes, such as the widespread use of benzene and asbestos, pose emerging risks to workers in manufacturing sectors. While environmental and health concerns about chemical exposure are still minimal, these early decades lay the groundwork for future investigations into the toxicological effects of industrial chemicals.
1940s	Chemical warfare and industrial growth	The 1940s, particularly during and after World War II, see increased attention on chemicals related to warfare, such as chemical agents used in combat. This period also sees an expansion in the use of synthetic chemicals in agriculture, particularly pesticides like DDT. Post-war industrialization leads to an explosion in chemical manufacturing, but the potential health and environmental risks of many of these chemicals are still not well understood. The decade’s events begin to raise concerns about the long-term effects of exposure to chemical substances, leading to the eventual establishment of chemical safety standards in future decades.
1950s	Rise of toxic awareness	The widespread use of pesticides such as DDT continues, and early environmental concerns emerge regarding the long-term effects on wildlife and ecosystems. The Great Smog of London in 1952, caused by coal burning and industrial pollution, highlights the deadly potential of chemical pollutants in the air. The decade also sees the growth of the chemical industry and the further proliferation of synthetic chemicals without sufficient regulatory oversight. As these risks begin to be recognized, the groundwork for future environmental and health regulations is laid, particularly around industrial chemical pollution and air quality. Experts extensively deliberate on the escalating issues of air pollution, the existence of pesticide residues and toxic dyes in food, and general concerns regarding pesticides.
1960s	The Environmental Revolution	The 1960s mark a significant turning point in public awareness of chemical risks. Rachel Carson’s 1962 book Silent Spring raises alarms about the environmental and health impacts of pesticides, especially DDT, sparking the environmental movement. The decade also sees a growing recognition of the need for oversight in industries that used toxic chemicals, laying the foundation for future environmental and chemical safety laws.
1970s	Regulatory beginnings	The decade is pivotal in addressing chemical risks with the establishment of key environmental protection laws. The creation of OSHA in the US helps regulate workplace chemicals, and the Clean Water Act of 1972 addresses chemical pollutants in water. The Toxic Substances Control Act of 1976 provides the EPA with the authority to regulate industrial chemicals and their risks. However, the widespread use of chemicals like asbestos, which is linked to serious health issues such as lung cancer, continues to raise alarm.
1980s	Chemical disasters and awareness	The 1980s bring attention to the devastating impact of chemical risks through major incidents like the 1984 Bhopal disaster, where a gas leak at a pesticide plant in India causes thousands of deaths and long-term environmental damage. This event highlights the risks of industrial chemicals in densely populated areas. The U.S. enacts the Superfund law in 1986, creating a program to clean up hazardous waste sites. The decade also sees the international community beginning to take action against substances like CFCs, which were depleting the ozone layer, culminating in the Montreal Protocol of 1987.
1990s	Global action and regulation	The 1990s see further development of international and national regulations aimed at addressing chemical risks. The Basel Convention of 1991 begins to control the transboundary movement of hazardous waste, and the Stockholm Convention in 2001 targets persistent organic pollutants (POPs) to protect human health and the environment. In the U.S., the Food Quality Protection Act of 1996 sets stricter pesticide safety standards. The decade also sees an increase in environmental awareness about the impact of chemicals on ecosystems, which influences the rise of green chemistry as an alternative to hazardous chemicals.
2000s	Tackling chemical pollution	The 2000s were marked by global efforts to regulate chemicals with a focus on environmental protection. The Stockholm Convention, aimed at eliminating persistent organic pollutants (POPs), came into effect, while the European Union implemented REACH, a comprehensive regulation addressing the safe use of chemicals in industry. The Deepwater Horizon oil spill in 2010 brings attention to the environmental risks posed by chemicals in the oil industry, while increasing concern over the safety of chemicals in consumer products, such as bisphenol A (BPA), leads to more scrutiny of their potential health impacts.
2010s	Chemical safety and green chemistry	Public awareness of chemical risks grows, especially regarding plastic pollution, with microbeads being banned in many countries. The period also sees increased regulatory scrutiny of chemicals like endocrine-disrupting substances, particularly in the EU and U.S. The Frank R. Lautenberg Chemical Safety for the 21st Century Act updates the Toxic Substances Control Act in the U.S., providing stronger protections against hazardous chemicals. Meanwhile, international efforts focused on eliminating harmful substances like mercury and promoting safer alternatives. This decade marked a shift toward greener, more sustainable chemical practices, driven by environmental and health concerns.

Full timeline

Inclusion criteria

We include:

• Major historical industrial accidents.

We do not include:

• Individual terrorist attacks.
• Biological agents (visit Timeline of biorisk).

Timeline

Year	Risk type	Event type	Agent	Details	Country/location
~1500 BCE	Non-intentional	Chemical hazard identification	Lead, copper, other substances	Ebers Papyrus in Ancient Egypt mentions the toxic effects of lead, copper, and other substances, one of the earliest records of chemical hazard awareness.	Egypt
370 BCE	Non-intentional	Chemical hazard identification	Metals	Hippocrates, often regarded as the "Father of Medicine," is credited with providing one of the earliest known clinical descriptions of abdominal colic, specifically in a patient involved in the extraction of metals.	Greece
c. 370–287 BCE	Non-intentional	Chemical hazard identification	Arsenic, mercury	Greek philosopher and naturalist Theophrastus of Eresus references arsenic and mercury in his treatise On Stones (Peri Lithon). This work contains some of the earliest recorded descriptions of minerals and metals, including arsenic (in the forms of realgar and orpiment) and mercury (quicksilver). His details accounts reveal an early recognition of the unique characteristics of these substances, as well as a rudimentary understanding of their potentially harmful effects.	Greece
1556	Non-intentional	Literature	Minerals, metals	German Humanist scholar Georgius Agricola publishes De Re Metallica, documenting mining and metallurgical practices and associated health hazards.	Germany
1675 (August 27)	Intentional (prevention)	International policy	Poison bullets	The Strasbourg Agreement is established between France and Germany, marking the first international treaty to restrict chemical weapons. This agreement specifically prohibits the use of poison bullets, reflecting early efforts to prevent the use of chemical warfare. The treaty signifies a pivotal moment in international law, aiming to protect combatants and civilians from the devastating effects of chemical agents in conflict.	France, Germany (Holy Roman Empire)
1771	Non-intentional	Chemical hazard identification	Hydrofluoric acid	Swedish pharmaceutical chemist Carl Wilhelm Scheele first synthesizes hydrofluoric acid. He discovers it while investigating fluorite (calcium fluoride). A very poisonous, highly irritating and corrosive substance, hydrofluoric acid would be researched as a chemical agent.
1775	Non-intentional	Chemical hazard identification	Ammonia	German-Swedish pharmaceutical chemist Carl Wilhelm Scheele identifies ammonia in its gaseous form and refers to it as "alkaline air". While he is the first to prepare and study the gas, his findings would be published at a later date. Ammonia is dangerous due to its toxicity and corrosiveness; it can irritate eyes, skin, and lungs, and high concentrations can be fatal.	Sweden
1825	Non-intentional	Chemical hazard identification	Strychnine	French chemists Pierre Joseph Pelletier and Joseph-Bienaimé Caventou successfully isolate strychnine in its pure crystalline form. Strychnine is a highly toxic alkaloid obtained from the seeds of the Strychnos nux-vomica, or nux vomica tree. Historically being used in medicine, due to its extreme toxicity, it would be mainly used as a pesticide to control rodents and birds in modern times. Strychnine acts as a powerful poison, affecting the nervous system and causing severe convulsions that can lead to death by respiratory failure.	France
1855	Non-intentional	Literature	Hazardous vapors	Belgian pharmacist Léon Peeters publishes a brochure titled Salubrité publique: Guérison radicale de la maladie des pommes de terre et d’autres végétaux, attributing the devastating potato plant epidemic of the late 1840s to hazardous vapors from the chemical industry. Peeters suggests that these vapors caused widespread famine in Europe and posed risks to small children through airborne poisons. The ensuing protests and expert testimonies reveal a blend of chemical and toxicological perspectives regarding gases like hydrogen chloride, sulfur dioxide, and nitrogen oxides, alongside traditional beliefs in the roles of miasmas and contagions in public hygiene.	Belgium, Europe
1865	Non-intentional	Chemical hazard identification	Hazardous vapors	Hermann Eulenberg, a German state physician, publishes a comprehensive textbook on hazardous vapors, synthesizing their effects on human health and vegetation. This work follows public concern sparked by Léon Peeters' 1855 brochure, which links a potato plant epidemic to harmful emissions from the chemical industry. Eulenberg's 500-page text categorizes suffocating and toxic gases into narcotic, irritating, and biolytic types, while also addressing gaseous miasmas and their epidemic consequences. This publication is significant in the development of public health and toxicology, laying foundational insights that would evolve into environmental toxicology.	Germany
1880	Non-intentional	Concept development	Multiple	The "minimal lethal dose" emerges as a crucial concept in toxicology during a period when industry begins playing a prominent role in the field. As the number of industry-produced chemicals surges, their often-unknown toxicological properties pose health risks to workers. Industrial toxicology gains prominence, and a paradigm shift occurrs, shaping the overall understanding of poisons. The concept of the "minimal lethal dose" becomes integral, serving as a quantitative measure to compare the toxicity of distinct acute poisons. This notion marks a significant step in quantifying the harmful effects of chemicals and establishing threshold values to assess their impact.
1890	Non-intentional	International policy	Multiple	The Berne Convention establishes the first international regulation governing the transportation of hazardous goods by rail. This landmark agreement aims to enhance safety standards and ensure the responsible handling of dangerous materials during rail transport. By setting guidelines for the movement of such goods, the convention marks a significant step towards international cooperation in managing chemical risks and protecting public safety in the burgeoning industrial age. As of November 2022, the Berne Convention would be ratified by 181 states out of 195 countries in the world, most of which are also parties to the Paris Act of 1971.	Swotzerland
1895	Non-intentional	Industrial toxic exposure	Aniline	Dr. Ludwig Rehn reports cases of bladder tumors among workers in the magenta department of a German aniline dyeworks. This discovery, presented at the Congress of the German Society of Surgery, marks one of the earliest instances of industrial carcinoma diagnosis. The affected workers were exposed to magenta, a chemical produced from aniline, for almost four decades. Subsequently, similar cases emerge in other aniline dyeworks, leading to the term "aniline cancer." This event highlights the link between industrial chemicals and cancer, foreshadowing future findings of carcinogenic properties in various industrial substances.	Germany
1912	Non-intentional	Industrial toxic exposure	Multiple	Swiss urologist S. G. Leuenberger documents instances of bladder cancer in eighteen dye factory employees in Basel, home to CIBA and Geigy. Analyzing death records from 1901 to 1910, Leuenberger determines that mortality rates from urinary passage tumors are thirty-three times higher among dye factory workers compared to those in different occupations.	Switzerland
1916 (March)	Intentional	Chemical agent development	Multiple	Porton Down is established in the UK to provide a scientific foundation for the British military's use of chemical warfare. This initiative is a direct response to Germany's deployment of chemical agents in 1915 during World War I. Porton Down aims to conduct research and develop effective chemical weapons and countermeasures, reflecting the growing importance of scientific inquiry in modern warfare and the need to address the challenges posed by chemical agents on the battlefield.	United Kingdom
1917-1918	Intentional	Facility	Multiple	The Chemical Warfare Service (CWS) constructs large-scale production plants primarily at Edgewood Arsenal in Maryland, which later would become part of the Aberdeen Proving Ground. At Edgewood Arsenal, three main plants become operational, producing chlorine, chloropicrin, mustard gas, and phosgene. Additionally, three shell-filling plants are set up to fill various types of projectiles with chemical agents. Renamed several times, the facility is now known as Edgewood Chemical Biological Center.	United States
1918 (May)	Intentional	Facility	Multiple	The United States Army Gas School is established at Camp A.A. Humphreys in Virginia, and begins instructing commissioned and noncommissioned officers in chemical warfare. The camp would transition to Fort Belvoir in 1935. Fort Belvoir, now a significant U.S. Army installation and census-designated place in Fairfax County, Virginia, encompasses the main base, Davison Army Airfield, and Fort Belvoir North. The shift from Camp A.A. Humphreys to Fort Belvoir marks a historical and operational evolution in military training and infrastructure.	United States
1918 (June 28)	Intentional	Organization	Multiple	The Chemical Warfare Service is established by General Order as a division of the U.S. Army. It would focus on defense against and utilization of nuclear, radiological, biological, and chemical weapons. It is formed to centralize efforts related to gas offenses. The Chemical Corps would oversee the development of offensive munitions.	United States
1919 (June 28)	Intentional	International policy	Multiple	The Treaty of Versailles bans Germany from manufacturing or stockpiling chemical weapons (among many things). This treaty, concluding World War I, aims to limit Germany's military capabilities and prevent the resurgence of chemical warfare. By explicitly addressing chemical weapons, the treaty reflects the international community's commitment to disarmament and the desire to mitigate the devastating impacts of chemical agents experienced during the war.	Germany
1925 (June 17)	Intentional	International policy	Multiple	The Geneva Protocol is created, with the purpose to prohibit the use of chemical and bacteriological methods of warfare. This protocol marks the first international endeavor to restrict the utilization of biological agents in warfare.
1925	Non-intentional	Literature	Fertilizers and pesticides	John Hepburn publishes Crop Production, Poisoned Food, and Public Health, in which he contends that the utilization of fertilizers and pesticides in agriculture constitute a significant factor contributing to cancer. He perceives cancer as a contagious ailment. This argument is associated with concerns about chemical risk, highlighting the potential dangers posed by the use of specific chemicals in agriculture and their potential impact on public health, particularly in terms of cancer development.
Early 1930s	Intentional	Wartime chemical research	Mustard gas	The Rawalpindi experiments begin as a series of experiments conducted on hundreds of Indian soldiers using Mustard gas by scientists from Porton Down, a British military research facility. These experiments would occur before and during World War II at a military installation in Rawalpindi, which is now located in Pakistan.	Pakistan
1930s	Non-intentional	Chemical agent development	Tabun	A German scientist creates Tabun, the first nerve agent, while attempting to develop a more potent pesticide. The German army would weaponize Tabun as a chemical weapon, and it would be followed by the development of Sarin and Soman in the late 1930s to early 1940s. American scientists would designate these agents as "G" agents, leading to Tabun being labeled GA, Sarin as GB, and Soman as GD. In the 1950s, more stable variants known as the V agents, including VX (Venom X) would be developed by the British in 1952, emerged. VX, characterized by increased stability, can persist in the environment for several weeks after release.
1936 (December23)	Non-intentional	Chemical hazard identification	G-series nerve agents	The first class of nerve agents, the G-series, is accidentally discovered in Germany by a research team headed by Gerhard Schrader working for IG Farben. This significant development in chemical warfare results from research into pesticides, leading to the identification of highly toxic compounds. The discovery marks a pivotal moment in the history of chemical agents, as the G-series would later be used in military applications, raising ethical concerns about their effects and the potential for mass destruction.	Germany
1943	Intentional (prevention)	Organization	Multiple	The United States Army Medical Research Institute of Chemical Defense (USAMRICD) is established to conduct research and development related to chemical defense and the medical management of chemical exposures. This institute aims to enhance the military's preparedness against chemical threats, particularly during World War II. USAMRICD focuses on studying the effects of chemical agents, developing protective measures, and improving medical treatment protocols, reflecting the growing recognition of chemical warfare's impact on soldiers and the need for effective countermeasures.	United States
1947	Non-intentional	Industrial accident	Ammonium nitrate	The Texas City disaster occurs when a fire aboard the French ship SS Grandcamp, which was carrying 2,300 tons of ammonium nitrate, triggers a massive explosion at the port of Texas City, Texas. The blast causes a 15-foot tidal wave, widespread fires, and the destruction of nearby chemical plants and oil tankers. Between 400 and 600 people are killed, and up to 4,000 are injured. A second explosion follows when another ship, the SS High Flyer, also detonates. The blast devastates the town and leaves thousands homeless.	United States
1948–1975	Intentional	Chemical risk operation	Multiple	The Edgewood Arsenal human experiments are conducted by the U.S. Army Chemical Corps as a secretive human subject research at Maryland's Edgewood Arsenal facility. The research aims to assess the effects of low-dose chemical warfare agents on military personnel and to test protective gear, drugs, and vaccines. A subset of these studies, known as the "Medical Research Volunteer Program" (1956-1975), focused on psychochemical warfare, including the development of more effective interrogation methods, in response to intelligence needs.	United States
1950	Both	International policy	Organization	The International Air Transport Association (IATA) issues its first list of recommendations for the air transport of dangerous goods. This initiative aims to enhance safety standards and regulatory compliance in the air transport of hazardous materials. The recommendations outline guidelines for packaging, labeling, and handling dangerous goods, reflecting the growing need for safety in the expanding global air transport industry. A revised edition of these guidelines would be released in 1956, further improving protocols for managing hazardous materials in aviation.
1952	Non-intentional	International policy	Multiple	The ILO Chemical Industries Committee proposes five basic symbols for hazardous materials: liquids spilling (corrosion), bomb (explosion), flame (fire), skull and crossbones (poison), and trefoil (radioactivity). The UN Economic and Social Council would adopt this ILO system in 1958.
1957	Non-intentional	International policy	Multiple	The European Agreement Concerning the International Carriage of Dangerous Goods by Road is adopted, representing the initial international agreement to regulate the road transport of hazardous materials. It would undergo regular updates and revisions over the following decades to accommodate evolving standards and ensure the safe international transportation of dangerous goods by road.	Europe
1957	Intentional	Bioweapon testing	Zinc cadmium sulfide	Operation LAC is launched to assess the release of aerosols from airplanes. The first experiment involves a region spanning from South Dakota to Minnesota, and subsequent tests extend to areas between Ohio and Texas and from Michigan to Kansas. The results of these experiments demonstrate the feasibility of large-scale deployment of a bioweapon from the air, as some test particles are found to travel distances of up to 1200 miles. This raises serious concerns about the potential implications of aerial bioweapon deployment and underscored the significance of biorisk management and international security measures.	United States
1961	Non-intentional	International policy	Multiple	The Berne Convention is revised to update regulations concerning the transportation of hazardous goods. This revision aims to enhance safety standards and improve the protocols for handling dangerous materials, reflecting advancements in transportation practices and a growing awareness of public safety concerns. The updated convention facilitates international cooperation in managing the risks associated with hazardous goods, reinforcing the commitment to safe and responsible transport in an increasingly interconnected world.
1962 (May)	Intentional	Facility	Multiple	The Joint Chiefs of Staff creates the Deseret Test Center at Fort Douglas, Utah, a decommissioned army base. DTC is tasked with overseeing chemical and biological weapons testing. This initiative, known as Project 112, would conduct various tests in land-based, Arctic, and tropical environments, ending in 1972. The testing locations include diverse settings such as land areas and barges in the Pacific Ocean.	United States
1962	Non-intentional	Literature	Multiple	Rachel Carson publishes Silent Spring, which focuses on the harmful impacts of pesticides, specifically DDT, on birds. The publication played a key role in the 1972 ban of DDT in the United States. Widely recognized for its influence, the book is credited with catalyzing the environmental movement and fostering a heightened concern for the enhanced regulation and management of pesticides and other chemicals.	United States
1965	Non-intentional	International policy	Multiple	The Intergovernmental Maritime Consultative Organization (IMCO), later known as the International Maritime Organization (IMO), plays a pivotal role in developing the International Maritime Dangerous Goods (IMDG) Code. This code is designed to enhance the safety of maritime transport by providing comprehensive guidelines for the handling, packaging, and labeling of dangerous goods transported by sea. The establishment of the IMDG Code reflects the growing recognition of the need for standardized practices to mitigate risks associated with hazardous materials in maritime shipping, ensuring the protection of people and the environment.
1969	Intentional (prevention)	National policy	Multiple	U.S. President Richard Nixon gives his speech Statement on Chemical and Biological Defense Policies and Programs, declaring an end to the U.S. offensive biological weapons program, upholding a no-first-use policy for chemical weapons, and excluding toxins, herbicides, and riot-control agents from the definition of chemical and biological weapons. Nixon expresses support for a minimal defense-focused research program, vows continued vigilance over other nations' biological programs, and articulates a desire to foster peace and understanding globally.	United States
1970	Non-intentional	National policy	Air pollutants	The United States takes a decisive step toward protecting public health and the environment by passing the landmark Clean Air Act. Prompted by decades of worsening air pollution and public outcry—culminating in the first Earth Day—Congress establishes strict national air quality standards, sets emissions limits for factories and vehicles, and requires states to implement compliance plans. The newly created Environmental Protection Agency is charged with enforcing these measures. Since its adoption, the Act would reduce particulate pollution by nearly 65%, extending average U.S. life expectancy by about 1.4 years, and transforming cities like Los Angeles from global smog capitals into models of cleaner air.	United States
1970 (December 2)	Non-intentional	National policy	Multiple	United States President Richard Nixon signs Reorganization Plan No. 3, formally creating the U.S. Environmental Protection Agency (EPA). This move follows growing public concern over environmental degradation, including polluted air and water, oil spills, and toxic waste. The plan consolidates various federal pollution control responsibilities into a single agency. William Ruckelshaus is confirmed as the EPA’s first Administrator, and on December 4, he signed EPA Order 1110.2 to structure the agency. The EPA is empowered to conduct environmental research, monitor pollution, set and enforce standards, and support state efforts to improve environmental quality across the country.
1971	Non-intentional	Organization	Multiple	OECD member countries, recognizing the need for international cooperation on chemicals, establish a Chemicals Group within the OECD. This decision is motivated by several factors, including the presence of major chemical-producing nations among OECD members, a shared "like-mindedness" facilitating agreements, the flexibility to make agreements legally or politically binding through OECD Council Acts, the ability to convene national experts, and the organization's multidisciplinary nature enabling beneficial interactions with various policy areas. The OECD provides a platform to address specialized scientific issues, serving as an interface between government regulators and scientists.
1971	Intentional	Facility	Multiple	Chemical weapons start being stockpiled on Johnston Atoll Chemical Agent Disposal System facility. This U.S. military installation is designated for the storage and eventual disposal of chemical agents, reflecting the ongoing Cold War tensions and the need for secure management of these hazardous materials. The facility would play a crucial role in the United States' chemical weapons program, emphasizing the complexities of disarmament and the challenges associated with safely handling and eliminating chemical warfare agents.	United States
1972	Non-intentional	International policy	Multiple	The Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals (BCH Code) is established. It precedes the International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk (IBC Code), which applies to chemical tankers built after July 1, 1986. The BCH Code regulates chemical tankers built before that date. It sets standards for the construction and equipment of ships carrying dangerous chemicals, aiming to mitigate risks to the ship, crew, and environment. The BCH Code categorizes chemicals based on their hazards and prescribes safety measures accordingly, ensuring compliance with the safety and environmental standards under the SOLAS Convention. BCH Code would undergo amendments between 1972 and 1983.	United Nations
1972	Non-intentional	National policy	Industrial pollutants	The U.S. Congress passes major amendments to the Federal Water Pollution Control Act, transforming it into what would be known as the Clean Water Act (CWA). This landmark legislation establishes the fundamental framework for regulating pollutant discharges into U.S. waters and sets water quality standards for surface waters. A key component is Section 404, which creates a program to regulate the discharge of dredged and fill material into waters, including wetlands. The 1972 amendments significantly expand federal authority over water pollution, emphasizing permitting systems (like Section 402’s NPDES) and empowering both federal and state agencies to enforce water protection.	United States
1974	Non-intentional	Chemical hazard identification	Chlorofluorocarbons	American chemist F. Sherwood Rowland and Mexican chemist Mario Molina publish a groundbreaking article in the scientific journal Nature, providing compelling evidence of the threats posed by chlorofluorocarbons (CFCs) to the stratospheric ozone layer. Their research demonstrates the harmful impact of these chemicals on the Earth's protective ozone layer. This work would become pivotal in raising awareness about the environmental risks associated with CFCs, as it would contribute significantly to the understanding of their role in ozone depletion. The recognition of their pioneering contributions would come in 1995 when Rowland, Molina, and Paul Crutzen are jointly awarded the Nobel Prize for Chemistry. The acknowledgment highlights the critical importance of their research in the field of atmospheric chemistry and its implications for global chemical risk, particularly in the context of ozone layer protection.	United States
1975 (April 8)	Intentional	National policy	Chemical herbicides	Executive Order 11850 is issued by United States President Gerald Ford, establishing the renunciation of certain uses of chemical herbicides and riot control agents in war as a national policy of the United States. It permits the use of herbicides for vegetation control within U.S. bases and installations and allows the use of riot control agents in specific defensive military situations to save lives. The order mandates that the Secretary of Defense ensures compliance with these policies and prohibits the use of such agents in war without prior presidential approval. This executive action aims to regulate the use of chemical agents in military operations and safeguard against their indiscriminate use.	United States
1975	Intentional	Chemical weapon deployment	Parathion, thallium, multiple	During the Rhodesian conflict, the minority white community in Rhodesia face challenges from native African nationalists. Stretched thin, Rhodesian forces adopt unconventional methods, employing commercially available poisons like parathion and thallium. They contaminate clothing, water sources, and food, resulting in an estimated 1,500–2,500 guerilla deaths, with numerous civilians affected. Facing native African nationalist insurgents, the Rhodesian forces struggled due to limited resources. Rhodesia's chemical warfare, marked by low-tech methods, demonstrate a brutal, yet unconventional approach to counter the growing power of the insurgent forces.	Zimbabwe (Rhodesia)
1975	Non-intentional	International policy	Multiple	The World Health Organization implements a categorization system for pesticides, considering factors such as their physical forms (solid, liquid, aerosol) and their potential harm in terms of acute and dermal toxicity to rats. This classification aims to systematically organize pesticides, facilitating the assessment of their risks.
1976 (July 10)	Non-intentional	Industrial accident	2,3,7,8-Tetrachlorodibenzodioxin	The Seveso disaster occurs at a chemical plant in Meda, Italy. A reactor explosion at the Icmesa Chemical Company releases a toxic cloud of dioxin and other pollutants, causing severe damage to crops, soil, and the environment within an 18 km radius. It results in numerous injuries, including 417 cases of chloracne, liver diseases, and abortions for high-risk pregnancies. The disaster prompted significant environmental legislation, leading to the adoption of the "Seveso Directive" by the European Union in 1982 to prevent similar catastrophes.	Italy
1976	Non-intentional	National policy	Multiple	The United States enact the Toxic Substances Control Act (TSCA), giving EPA authority to regulate chemical substances and mixtures. TSCA requires reporting, record-keeping, testing, and restrictions; mandates premanufacture notifications for new chemicals; allows Significant New Use Rules; creates the TSCA Inventory of chemicals; and requires import/export certifications and reporting of substantial risk information. Certain categories—food, drugs, cosmetics, and pesticides—are excluded. TSCA covers the chemical life cycle, including PCBs, asbestos, radon, and lead-based paint, and would be later updated by the 2016 Lautenberg Act.	United States
1982	Non-intentional	International policy	Industrial chemicals	The Seveso Directive is adopted by the European Economic Community (EEC) following the 1976 Seveso disaster. It establishes mandatory safety requirements for sites handling large quantities of dangerous substances.	European Union
Early 1980s	Intentional	Biological warfare program	Multiple	Project Coast starts operating as South Africa's covert Chemical and Biological Warfare (CBW) program. Operational until early 1990s, the program would be found to have developed lethal chemical and biological weapons, including sterilization toxins and concealed poisons, targeting African National Congress political leaders and black township populations. Project Coast would be accused of contaminating water supplies with cholera, aiding Rhodesian troops with anthrax and cholera, and employing toxic agents for political assassinations. Investigations would lead to dismissals and document destruction, with South Africa officially maintaining the program's defensive nature, despite international concerns.	South Africa
1984 (December 2–3)	Non-intentional	Industrial accident	Methyl isocyanate	The Bhopal Disaster occurs at the Union Carbide India Limited pesticide plant in Bhopal, India. It is one of worst industrial disasters in history. Over 35 tons of toxic gases, including at least 24 tons of methyl isocyanate (MIC), leak from the plant, resulting in immediate deaths of at least 3,800 people and causing significant morbidity and premature death for many thousands more. The aftermath of the disaster would lead to chronic health issues among survivors, with ongoing environmental contamination at the site. Towards the 21st century, the site remains uncleared, and contamination persists, with groundwater and well-water testing in 1999 revealing mercury levels far exceeding safe limits.	India
1985	Non-intentional	International policy	Multiple	The 1985 United Nations Vienna Convention for the Protection of the Ozone Layer is held as an international treaty aimed at addressing the environmental and health risks associated with the release of certain chemicals known to deplete the ozone layer. It is a landmark agreement that addresses chemical risks associated with ozone depletion.	Austria
1987 (September 16)	Non-intentional	International policy	CFCs	The Montreal Protocol on Substances that Deplete the Ozone Layer is adopted in Montreal. It aims to protect the ozone layer by phasing out production and consumption of ozone-depleting substances, such as chlorofluorocarbons (CFCs). The treaty would enter into force on 1 January 1989, with 46 signatories at adoption and later achieving universal participation with 198 parties. Over time, it would be amended and adjusted multiple times to accelerate phase-out schedules and include additional substances. The protocol would be widely regarded as one of the most successful international environmental agreements, significantly contributing to ozone layer recovery.	Global
1987	Non-intentional	Agricultural chemical crisis	Mycotoxins	Approximately 100 individuals in India become ill after consuming wheat products contaminated with mycotoxins, which are a result of heavy rains affecting crop quality. This incident highlights the public health risks associated with mycotoxin contamination in food supplies, emphasizing the need for improved agricultural practices and monitoring systems to ensure food safety. The outbreak serves as a reminder of the potential dangers posed by environmental factors on food quality and human health.	India
1988	Both	Literature (journal)	Multiple	Chemical Research in Toxicology is first issued by the American Chemical Society. It is a peer-reviewed journal. It would be indexed in databases like CAS, SCOPUS, and PubMed. Edited by Lawrence J. Marnett, it covers toxicology, medicinal chemistry, and multidisciplinary chemistry. It releases articles, communications, reviews, chemical profiles, and perspectives on advances in toxicology. The journal aims to present research on the chemical basis of toxicological responses, emphasizing rigorous chemical standards and modern analytical techniques. It covers various aspects including identification of toxic agents, molecular mechanisms of toxicity, and effects like mutagenicity and carcinogenicity.	United States
1989 (March 22)	Non-intentional	International policy	Hazardous waste	The Basel Convention is adopted in response to the growing international concern over hazardous waste dumping, especially in developing countries. The issue had gained prominence along the decade, following toxic waste scandals in Africa and tightening environmental laws in industrialized nations. UNEP had initiated the negotiation process in 1987, following approval of the Cairo Guidelines and a proposal from Switzerland and Hungary. A working group, having held five sessions from 1988 to 1989, culminates in a Conference of Plenipotentiaries in Basel, where 116 states unanimously adopt the Convention and eight related resolutions. It would enter into force on 5 May 1992.
1990	Intentional	Chemical weapon deployment	Chlorine gas	During the Sri Lankan Civil War, the Liberation Tigers of Tamil Eelam (LTTE) separatists are credited with the first non-state use of chemical weapons during their assault on the East Kiran base of the Sri Lanka Army using commercial chlorine gas.	Sri Lanka
1993 (January 13)	Intentional (prevention)	International policy	Multiple	The Chemical Weapons Convention (CWC) is introduced. It's a global treaty aimed at banning the development, production, possession, and use of chemical weapons during warfare. The Convention is formulated by the United Nations Conference on Disarmament and approved by the UN General Assembly in 1992. It would be subsequently signed by 130 countries during a three-day conference in Paris. CWC would take effect on April 29, 1997.
1994	Non-intentional	International policy	Multiple	The Organization for Economic Co-operation and Development (OECD) initiates a harmonization effort, collaborating with both OECD member nations and several non-member economies. The objective is to standardize the criteria for classifying human health and environmental hazards. Concurrently, a United Nations expert group and the International Labour Organisation (ILO) addresses physical hazards and hazard communication. The outcomes of the OECD's endeavors, presented in 2001, serves as the foundation for the establishment of the Globally Harmonised System of Classification and Labelling of Chemicals (GHS) in 2002.
1995 (March 20)	Intentional	Terrorist attack	Sarin	The Tokyo subway sarin attack is perpetrated by Aum Shinrikyo, a Japanese doomsday cult led by Shoko Asahara, when their members release sarin gas in the Tokyo subway system, causing 13 deaths and over 5,800 injuries. The cult, evolving from a spiritual group in the 1980s, shocks Japan, exposing police oversights. Asahara and 13 members receive death sentences. Despite going underground and renaming as Aleph, the cult would persist. The Tokyo subway sarin attack would raise global concerns about the potential use of chemical agents as tools of terror, and it would lead to heightened awareness of the importance of biorisk management and counterterrorism measures.	Japan
1996 (August 3)	Non-intentional	National policy	Pesticides	The Food Quality Protection Act (FQPA) is unanimously passed by the US Congress and signed by President Clinton on August 3, amending the Federal Insecticide, Fungicide, and Rodenticide Act and the Federal Food, Drug, and Cosmetic Act. It overhauls EPA pesticide regulation by requiring a “reasonable certainty of no harm” standard for tolerances, special protection for children, and consideration of aggregate and cumulative exposure. The EPA reassesses all existing tolerances over 10 years, revoking or modifying nearly 4,000 of 9,721. The FQPA also promotes reduced-risk pesticides, protects minor uses, addresses public health pests, initiates endocrine disruptor screening, and mandates 15-year registration reviews.	United States
1997	Intentional	Terrorist chemical research	Phosgene, chlorine,hydrogen cyanide	Al Qaeda first starts researching and experimenting with chemical weapons in Afghanistan, testing phosgene, chlorine and hydrogen cyanide. This initiative marks a significant shift in the group's focus on developing capabilities for unconventional warfare. The experimentation highlights the potential threat posed by terrorist organizations seeking to utilize chemical agents, raising alarms about the risks of chemical terrorism and the necessity for enhanced security measures and counter-terrorism efforts.
1999	Non-intentional	Agricultural chemical crisis	Dioxin	The Belgian PCB/dioxin incident occurs when accidental dioxin-contaminated polychlorinated biphenyls are added to recycled fat in animal feeds, affecting over 2500 farms. A monitoring program finds a single PCB oil source (50 kg) with 1g TEQ dioxins. Chickens and reproduction animals show higher concentrations, indicating chick edema disease. Despite some food products exceeding recommended values by over 100 times, adverse effects on the general population are unlikely. The incident exposes metabolic differences in farm animals' PCBs and dioxins elimination. The crisis leads to a major food crisis, political resignations, and international actions, impacting global trade and causing economic losses. The incident highlights the potential dangers of chemical contamination in the food chain, demonstrating the risks associated with the mishandling and introduction of hazardous chemicals into agricultural processes.	Belgium
2000 (January 30)	Non-intentional	Industrial accident	Cyanide	The Baia Mare cyanide spill occurrs when a dam at the Aurul SA gold mine in Romania fails, releasing around 100,000 cubic meters of cyanide-laced waste. The toxic sludge enters the Săsar, Lapus, Someș, Tisza, and Danube rivers, eventually reaching the Black Sea. The spill causes extensive ecological damage, including mass fish deaths—affecting 62 species, 20 of which are protected—and disrupted drinking water supplies. It also severely impacts the fishing industry and local economies. While authorities act quickly to prevent human casualties, the environmental and economic consequences are expected to persist for decades.	Romania
2000	Intentional	Literature	Multiple	United States chemical and biological weapons expert Jonathan B. Tucker publishes Toxic Terror: Assessing Terrorist Use of Chemical and Biological Weapons, which delves into the alarming potential for chemical and biological weapons (CBW) terrorism. The book addresses the concerns of policymakers, scholars, and the media regarding the global spread of knowledge and technology relevant to CBW terrorism. It assesses terrorist groups and individuals capable of acquiring and using CBW agents, their motivations, and the likely types of toxic agents and delivery methods. Through in-depth case studies of twelve such entities from 1946 to 1998, researched from primary sources, the book identifies patterns of behavior associated with CBW terrorism. These insights aim to inform prudent and cost-effective strategies for prevention and response.	United States
2001	Non-intentional	International policy	Persistent organic pollutants	The Stockholm Convention on Persistent Organic Pollutants is adopted and opened for signature at a Conference of Plenipotentiaries in Stockholm (22–23 May). Developed through a UNEP-led process since 1995, with negotiations completed in December 2000, the treaty targets an initial list of 12 POPs and set procedures to add more chemicals. The conference adopts resolutions on interim arrangements, the Secretariat (inviting UNEP to convene INC sessions), and liability and redress. Convention would enter into force on 17 May 2004.	United Nations
2001 (September 21)	Non-intentional	Industrial accident	Ammonium nitrate	The AZF industrial disaster occurs when 300–400 tons of ammonium nitrate explodes at the AZF fertilizer plant in Toulouse, France, killing 31 people and injuring over 2,500. The blast devastates the plant, destroys 25,000 homes, damages schools and businesses, and causes €2 billion in damages. Environmental pollution affects air and water quality, and thousands seek medical and psychological help. Investigations conclude the cause to be an accidental chemical reaction between ammonium nitrate and sodium dichloroisocyanurate.	France
2003	Non-intentional	International policy	Multiple	The United Nations adopt the Globally Harmonized System of Classification and Labeling of Chemicals (GHS), establishing standardized criteria for identifying health, physical, and environmental hazards. The system sets requirements for hazard communication through consistent labels and safety data sheets. The United States actively participate in its development and join UN bodies to coordinate implementation. The GHS aims to improve workplace chemical safety and harmonize regulations worldwide. Its adoption marks the foundation for later national regulatory changes, including OSHA’s efforts to align its Hazard Communication Standard with the GHS, a process initiated in subsequent years through formal rulemaking.
2006 (February)	Non-intentional	International policy	Multiple	The International Conference on Chemicals Management (ICCM) adopts the Strategic Approach to International Chemicals Management (SAICM) in Dubai. SAICM is a global policy framework aiming for the sound management of chemicals throughout their life cycle so that, by 2020, they would be produced and used with minimal harm to health and the environment. It includes the Dubai Declaration, Overarching Policy Strategy, and Global Plan of Action, covering areas like pesticide regulation, risk reduction, and waste management. The FAO Council endorses SAICM in November 2006, recognizing its alignment with FAO’s pesticide management work and its role in advancing sustainable agriculture.
2007	Non-intentional	International policy	Industrial chemicals	The European Union implements the REACH Regulation (EC 1907/2006), a major law aimed at protecting human health and the environment from risks posed by chemicals. REACH shifts responsibility to manufacturers and importers to assess and manage these risks, requiring them to register substances with the European Chemicals Agency (ECHA). The regulation introduces processes for evaluating, authorizing, and restricting substances of very high concern and emphasizes promoting innovation, non-animal testing methods, and consumer transparency. REACH also marks the beginning of a centralized EU framework for chemical regulation, with periodic reporting obligations for national authorities.	European Union
2007	Non-intentional	National policy enforcement	Mercury, VOCs, carcinogens	DuPont is fined $10.25 million by the U.S. EPA and DOJ for numerous chemical risk violations, including failure to report substantial risk information about perfluorooctanoic acid (PFOA) used in Teflon production.	United States
2008	Non-intentional	Industrial toxic exposure	Melamine	China’s melamine-tainted milk scandal erupts when 16 infants in Gansu are diagnosed with kidney stones linked to adulterated formula, chiefly from Sanlu. Within four months, an estimated 300,000 babies become sick and at least six die from kidney damage. The crisis quickly implicates multiple dairy firms, devastates confidence in domestic dairy, and damages China’s food-export reputation. The industry contracts through mergers and consolidation as consumers shift to foreign baby formula brands. The scandal exposed deep regulatory failures and catalyzes major reforms, paving the way for China’s 2009 Food Safety Law and, later, the creation of the China Food and Drug Administration in 2013.	China
2009	Non-intentional	International policy	Multiple	The CLP Regulation enters into force in the EU, aligning chemical classification and labeling with the GHS. It replaces previous EU legislation and becomes the basis for harmonized communication of chemical hazards.	European Union
2009	Non-intentional	Technological innovation	Multiple	The U.S. EPA launches the ToxCast program, using high-throughput screening and computational models to predict the toxicity of chemicals. This marks a shift toward integrating bioinformatics into regulatory toxicology.	United States
2010	Non-intentional	Industrial accident	Oil, dispersants	The Deepwater Horizon oil spill in the Gulf of Mexico becomes one of the worst marine chemical disasters. Massive amounts of crude oil and chemical dispersants lead to long-term environmental and human health concerns.	United States
2013	Non-intentional	International policy	Mercury	The Minamata Convention on Mercury is signed. It aims to protect health and the environment from mercury emissions and releases, inspired by the Minamata disaster and scientific understanding of mercury’s toxicity.	Global
2013	Non-intentional	National policy	Triclosan, microbeads	The FDA bans triclosan in consumer antiseptic washes due to evidence of endocrine disruption and bacterial resistance. This marks a major shift away from ineffective or harmful “antibacterial” chemicals.	United States
2013	Non-intentional	International policy	Endocrine-disrupting chemicals	The 2013 UN report State of the Science of Endocrine Disrupting Chemicals, published by UNEP and WHO, warns that many synthetic chemicals—especially those with hormone-disrupting properties—may pose serious risks to human and wildlife health. These endocrine disrupting chemicals (EDCs), found in everyday products like pesticides, cosmetics, and plastics, can interfere with hormone systems, potentially contributing to disorders such as reproductive issues, cancers, developmental and neurological problems. The report emphasizes the need for more research, improved testing, and better reporting to identify and manage EDC risks. It calls for international collaboration to reduce exposure and safeguard public and environmental health.
2014-2019	Non-intentional	Legal case / enforcement	Lead	The Flint water crisis occurs after a state-appointed manager switches the city’s supply to the Flint River without corrosion control. Lead leaches from pipes, exposing ~100,000 residents; a Legionnaires’ outbreak is suspected (12 deaths). Michigan and the U.S. declare emergencies in January 2016. Officials resign and later face charges; civil litigation yields a $641 million settlement, mostly for affected children. Extensive service-line replacements restore regulatory compliance, yet distrust persists and many residents would continue to avoid tap water.	United States
2015	Non-intentional	International policy	Multiple	The 2030 Agenda for Sustainable Development is adopted by the United Nations. It includes Goal 12.4, which emphasizes sound management of chemicals and waste to minimize their adverse impacts on health and the environment.	Global
2015	Non-intentional	International policy	Multiple	The United Nations adopts the 2030 Agenda for Sustainable Development, which includes a specific goal related to chemical safety. This agenda emphasizes the importance of ensuring the sound management of chemicals and waste to protect human health and the environment. By integrating chemical safety into broader sustainable development efforts, the agenda highlights the need for global cooperation in minimizing the risks associated with hazardous substances, promoting safe practices, and fostering a healthier, more sustainable future.
2015 (April 18)	Non-intentional	International policy	Lead paint	The Global Alliance to Eliminate Lead Paint—co-led by UNEP and WHO—announces at the Global Citizen 2015 Earth Day event in Washington, D.C., its goal to eliminate lead in paint worldwide by 2020. Actor Don Cheadle, UNEP officials, and the U.S. EPA emphasizes the health dangers of lead paint, especially for children and pregnant women. Despite existing alternatives, many countries still allow lead in paints. The Alliance calls for global regulatory action, drawing on the success of phasing out leaded gasoline. The announcement forms part of broader environmental and anti-poverty commitments made at the Earth Day celebration.	Global
2016	Non-intentional	National policy	Multiple	The Frank R. Lautenberg Chemical Safety for the 21st Century Act is signed into law, overhauling the TSCA by mandating EPA risk-based chemical evaluations and granting new regulatory authority.	United States
2016	Non-intentional	National policy	Microbeads	The U.S. Microbead-Free Waters Act is signed into law, banning plastic microbeads in cosmetics and personal care products due to their persistence in aquatic environments and potential for chemical accumulation in organisms.	United States
2018 (April 27)	Non-intentional	National policy	Pesticides	EU Member States vote to fully ban the outdoor use of three neonicotinoid insecticides—Bayer’s imidacloprid and clothianidin, and Syngenta’s thiamethoxam—within six months, following an EFSA assessment confirming their risk to wild and honeybees. A partial ban had been in place since 2013. The chemicals may sin then only be used on plants grown entirely in permanent greenhouses. Environmental groups welcome the move, though Greenpeace EU and others call for broader restrictions, noting other bee-harmful pesticides remain legal. The pesticide industry criticizes the decision and has three ongoing legal challenges against the European Commission over neonicotinoid restrictions.	European Union
2018	Non-intentional	Legal case / enforcement	Glyphosate	A San Francisco jury orders Monsanto to pay $289 million to Dewayne Johnson, a school groundskeeper with non-Hodgkin’s lymphoma, finding that glyphosate-based herbicides Roundup and RangerPro had substantially contributed to his illness and that Monsanto acted with malice by failing to warn consumers. The verdict—the first to try alleged glyphosate–cancer links—prompts Monsanto (by then owned by Bayer) to announce an appeal. The case would serve as a bellwether for thousands of similar U.S. claims amid continuing scientific and regulatory controversy.	United States
2018	Non-intentional	National policy	Asbestos	Brazil bans the use and commercialization of asbestos, becoming one of the largest developing nations to outlaw the substance due to its well-documented link to mesothelioma and lung disease.	Brazil
2019	Non-intentional	National policy	Glyphosate	Austria becomes the first EU country to vote in favor of a nationwide ban on glyphosate, citing cancer concerns and growing public demand for pesticide regulation.	Austria
2020 (May 7)	Non-intentional	Industrial accident	Styrene	The Visakhapatnam gas leak occurs at an LG Polymers Private Limited plant in Andhra Pradesh, leading to eight fatalities and over a thousand hospitalizations. Styrene is confirmed to be the leaked gas due to insufficient maintenance. LG Chem cites inadequate maintenance, stagnation, and temperature changes within storage tanks as causes. Styrene, widely used in resin and plastic production, poses health risks to the central nervous system. Despite dissipating from air within days, it persists in soil and water. The incident highlights the dangers of industrial negligence and underscores the need for stringent safety measures.	India
2020 (August 4)	Non-intentional	Industrial accident	Ammonium nitrate	A massive explosion in Beirut, Lebanon, kills over 200 people and injures more than 7,000. The blast is caused by a fire that ignites 2,750 tons of ammonium nitrate stored unsafely in a port warehouse since its confiscation in 2013. Despite repeated warnings, the government failed to act. The explosion devastated much of the city, prompting widespread protests and the resignation of Prime Minister Hassan Diab’s government. The disaster exposed deep governance failures and sparked calls for reform. International aid, including $300 million pledged by the UN, was mobilized to support the recovery and affected population.	Lebanon
2020				The European Union launches the Chemicals Strategy for Sustainability (CSS) under the European Green Deal, aiming to reduce chemical pollution, protect health and the environment, and boost innovation. To date, progress had been made, including updates to key regulations, but major actions like revising the REACH Regulation and banning hazardous chemical exports remain unfulfilled. Scientific evidence continues to highlight the dangers of chemical mixtures and persistent pollutants like PFAS. Despite new initiatives, fragmented implementation and lack of coordination risk undermining the EU's goals. A stronger focus on completing commitments and aligning strategies would be found to be crucial for achieving a toxic-free, sustainable chemical industry.
2021	Non-intentional	Scientific milestone	Microplastics	Scientists report the first detection of microplastics in human blood, with particles found in 17 of 22 healthy adult donors. Common plastics identified include PET (from bottles), polystyrene (from packaging), and polyethylene (from bags). The study reveals that these particles can circulate in the bloodstream and potentially lodge in organs, though health effects remain unclear. Experts express concern due to known lab toxicity and links to pollution-related deaths. The findings call for urgent further research, especially given growing plastic production and vulnerability in babies and children. Funding for health impact studies is sought.	Netherlands / Global
2022 (December 20)	Non-intentional	National policy enforcement	PFAS	American multinational conglomerate 3M announces it will cease manufacturing per- and polyfluoroalkyl substances (PFAS) and phase out their use across its product portfolio by the end of 2025. The decision follows growing regulatory pressure and changing stakeholder expectations regarding PFAS’s environmental and health risks. 3M agrees to discontinue producing all PFAS-based products, including fluoropolymers and fluorinated fluids, while supporting customer transitions. Financially, PFAS manufacturing represents about $1.3 billion in annual net sales; the exit would result in pre-tax charges of $1.3–2.3 billion. Despite PFAS’s utility in various technologies, 3M plans to innovate safer alternatives and maintain product performance without PFAS.	United States / Global
2023 (February)	Non-intentional	National policy	PFAS	The European Chemicals Agency (ECHA) publishes details of a proposed EU-wide ban on around 10,000 per- and polyfluoroalkyl substances (PFAS), aiming to prevent environmental contamination. Drafted by the Netherlands, Germany, Denmark, Norway, and Sweden under the REACH Regulation, this would be one of Europe’s largest chemical bans. PFAS are widely used in products like electronics, cosmetics, medical devices, and clothing. The proposal includes a transition period of 1.5 to 12 years, depending on the application and availability of alternatives. Formal consultations begin in March 2023, with the European Commission expected to decide on the proposal in 2025.	European Union
2023	Non-intentional	National policy	Bisphenol A (BPA)	France moves to reduce the acceptable daily intake of BPA by 20,000 times, following EFSA’s conclusion that BPA may pose significant immune system risks at previously accepted levels.	France / European Union

Numerical and visual data

Google Ngram Viewer

The Google Ngram Viewer chart below displays the frequency of the term chemical risk in books from 1900 to 2019. The graph shows that the term was virtually nonexistent before 1960 but began to rise steadily in the 1970s. This increase aligns with growing environmental awareness, industrial safety concerns, and regulatory developments, such as the formation of the United States Environmental Protection Agency (EPA) in 1970. The peak in the 1990s suggests heightened discourse on chemical hazards, possibly due to high-profile incidents and stricter regulations. After some fluctuations in the 2000s and 2010s, the term's usage slightly declines, indicating evolving language or shifts in focus.

Google Trends

The Google Trends chart for the term chemical risk shows its search interest from 2004 to the present. Initially, searches were relatively high but declined after 2005, remaining low until around 2016. From that point, interest gradually increased, with a noticeable surge after 2020. The recent rise may reflect heightened discussions on chemical safety in response to global industrial and environmental challenges.

Wikipedia views

The chart below displays Wikipedia page views for the article "Chemical hazard" from 2016 to 2025. Total views peaked around 2020-2021, likely due to the COVID-19 pandemic, before stabilizing. Post-peak, views returned to a baseline, with seasonal fluctuations evident. This analysis underscores the impact of global events on information-seeking behavior and the increasing reliance on mobile access for digital information.

Meta information on the timeline

How the timeline was built

The initial version of the timeline was written by Sebastian Sanchez.

Funding information for this timeline is available.

Feedback and comments

Feedback for the timeline can be provided at the following places:

• FIXME

What the timeline is still missing

• List of weapons of mass destruction treaties
• https://emergency.cdc.gov/agent/agentlistchem.asp

See also

• Timeline of biorisk
• Timeline of pollution