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Toxipedia was launched in June 2006 and has steadily grown, now offering more than a thousand pages of information on toxic chemicals, ethical considerations, laws and regulation, the history of toxicology, green chemistry, and much more. 

Our goal is to provide scientific information in the context of history, society, and culture so that the public has the information needed to make sound choices that protect both human and environmental health.

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Lessons Learned: Looking Back to Go Forward

#11: Thomas Midgley, Jr.: Developed Tetraethyl Lead for Gasoline


Thomas Midgley, Jr. (May 18, 1889 - November 2, 1944), an American chemist, developed the tetraethyl lead (TEL) additive for gasoline and chlorofluorocarbons (CFCs) and held over a hundred patents. While lauded for his discoveries during his time, today his legacy is seen as far more mixed considering the serious negative environmental impacts of these innovations. One historian remarked that Midgley "had more impact on the atmosphere than any other single organism in Earth's history."

Midgley tried hundreds of compounds to control engine knock. On December 9, 1921, a chemist delivered a small amount of tetraethyl lead, or TEL, and when Midgley added the TEL to the fuel and started the one-cylinder test engine, the engine knock was gone. GM and Standard Oil of New Jersey (forerunner of Exxon) formed the Ethyl Corporation shortly thereafter to produce TEL. The company's name was carefully chosen to avoid the use of the word "lead," but safeguards at the factory weren't as effective. Not long after it opened, workers at the Ethyl plant began suffering from lead poisoning. Two workers died from exposure to what the press called "loony gas." Midgley himself suffered from lead poisoning and took a vacation to "get a large supply of fresh air." Ironically, Midgley would later develop freon, a refrigerant that cooled indoor air for nearly half a century.

In 1922, the US Public Health Service warned of the dangers of lead production and leaded fuel. However, these precautionary warnings went unheeded, and the primary phase-out of leaded gasoline in the US was not completed until 1984. The World Bank called for a ban on leaded gasoline in 1996 and the European Union banned leaded gasoline in 2000. It is estimated that 7 million tons of lead were released into the atmosphere from gasoline in the United States alone.

Learn more on Toxipedia:

Environmental Health Effects of Marijuana Cultivation

Following the legalization of recreational marijuana in Washington and three other states, questions are arising about the environmental health impacts of marijuana cultivation, particularly in terms of energy and pesticide use. We are pleased to present a new article exploring the topic! Learn more about marijuana's environmental health impacts here!

Toxic Chemicals in Food Packaging


Various chemicals used in food storage and handling materials can leach into foods and be ingested. In recent years there has been particular focus on bisphenol-A, found in plastic bottles (such as water bottles and baby bottles) and food can liners; phthalates, found in materials made of flexible vinyl plastic (PVC or polyvinyl chloride plastic); and perfluoroalkyl and polyfluoroalkyl substances (PFASs, also known as PFCs), applied to some paper food wrappers and boxes to impart stain-resistance.

Learn more in our new article, which includes information on health effects, regulation, reducing exposure, and more! 

Toxic Pollution and Climate Change


The problems of toxic pollution and climate change have traditionally been explored and addressed as separate issues. However, these phenomena interact and overlap in various ways: activities and industries that release greenhouse gases into the atmosphere often also release toxic chemicals, and climate change can change the activity of toxic chemicals in the environment. Our new article provides an outline of some of these intersections, with the goal of spurring a more holistic understanding of these critical issues. Read the article here!

New Resource: A Global Bibliographic Perspective of Toxicology


Toxipedia is pleased to host A Global Bibliographic Perspective of Toxicology, a website devoted to the history of toxicology and allied sciences. Based on an article published in the International Journal of Toxicology in 2006, the bibliography contains over 2,500 searchable references compiled by Dale A. Stirling, an environmental and public health historian.

Topic areas include Informatics, Bibliometrics, and Scientometrics, the Toxicology Profession, Global Practice of Toxicology, and Toxicology Concepts, Disciplines, and Theories.

To access the bibliography, please visit or!

Facts on Crumb Rubber 

We are excited to announce, our new page on crumb rubber, the controversial material used as infill in artificial turf fields. Content includes ingredient information, exposure routes, health hazards, overviews of scientific studies, position statements, alternative materials, and more! Warm thanks to Laura Johnson of the Washington Alliance for Non-toxic Play and Athletic Fields for authoring this page. Visit the page here!


Milestones of Toxicology Poster Translated into Serbian Cyrillic and Latin!

The translation of the Milestones of toxicology poster into Serbian Cyrillic and Serbian Latin was coordinated by Danijela Đukić-Ćosić PhD, Department of Toxicology "Academic Danilo Soldatović", University of Belgrade – Faculty of Pharmacy. Danijela is currently working to translate "A Small Dose of Toxicology" into Serbian. A PDF file of the Serbian Cyrillic version of the Milestones of Toxicology poster can be downloaded HERE. A PDF file of the Serbian Latin version of the Milestones of Toxicology poster can be downloaded HERE. The Latin alphabet poster will be understood in Croatia and Montenegro, and the Cyrillic alphabet poster in Bosnia and Herzegovina, Montenegro, Macedonia, all former Yugoslav republics, and in Bulgaria, because the Bulgarian and Serbian languages are similar. Thank you Danijela! 


New Resource: A Story of Health

Case-based learning has long been used in medical education. A Story of Health is an eBook that grounds the science of health in stories of fictional people, their families, and communities to enable readers to explore the risk factors for disease as well as how to prevent disease and promote health and resilience. Using the setting of a family reunion as a backdrop, the book explores how multiple environments influence our health across the lifespan.

The stories are accessible to an educated lay audience with more technical sections for scientists and medical professionals who can access free continuing education credits through the eBook. A Story of Health was developed by the Agency for Toxic Substances and Disease Registry (ATSDR); the Collaborative on Health and the Environment (CHE); the University of California, San Francisco, Pediatric Environmental Health Specialty Unit (UCSF PEHSU); the Office of Environmental Health Hazard Assessment, California EPA (OEHHA); and the Science and Environmental Health Network (SEHN).

"Scientists must make both science education and community outreach a much more central part of the scientific culture."

-Bruce Alberts, Editor-in-chief, Science magazine (Dec 3, 2010 editorial)