Oppy Wood, 1917, Evening (1918) by British artist John Nash. Nash fought in the war from November 1916 to January 1918.

Imperial War Museum

Chemical Warfare: From the European Battlefield to the American Laboratory

During World War I the effects of poison gas extended far beyond the battlefield to laboratories, factories, and government.

The Observer

One winter night in 1916 James Robb Church boarded the ferry Sussex, sailing from England to France. With war raging in Europe the journey was likely a tense one. The ship was so full that some passengers huddled on deck for the five-hour trip. Two months later the Sussex would be torpedoed by a German U-boat, but on that night the trip across the channel went smoothly.

The United States had so far stayed out of the conflict in Europe, so for an American like Church the war had remained a distant affair. But that winter he was sent to France to gather information on Allied hospitals, ambulance routes, and medical posts. Church was an experienced surgeon whose service in the Spanish-American War had earned him a Medal of Honor. The combat in Europe was different, though. Along the Western Front he encountered wounded men who suffered not only from bombs and bullets but also from chemicals that burned like fire in the lungs and on the skin.

Church arrived in Paris before daybreak, and his first direct encounter with the war came that evening. He went to see a moving picture, and when he left the theater, the city was cloaked in the protective cover of darkness. Everyone seemed to be waiting to hear the whistle of German bombs. “There were crowds of people in the streets, watching the skies,” Church wrote later. “Pencils of white streaked the heavens and there seemed to be a rapt attention in the air of the low-voiced French speaking people.”

On orders from his superiors Church soon went looking for the conflict. In the trenches near Verdun he came within 40 feet of German-occupied soil and heard shells explode nearby. One fell on a shelter he’d only just departed, killing the French doctor who had shown him around. Mostly, though, the hills of France were quiet. “It was very still, the stillness of the high places accentuated by the tension of ever waiting for the scream of shells and the scrambling rush of infantry attack. It seemed like Sunday: the Sunday hush.”

At the end of one trench Church noted a seemingly unimportant detail: a detached automobile horn. “When that squawked it was better to put on your mask,” he wrote, “for it meant that the deadly gray, green gas was coming.”

Toxic gases became an urgent field of scientific inquiry, a thriving industry, and, in the minds of some, a necessary and even humane reality.

This was one small signal of a pivotal shift in warfare. France had experimented with tear gases first, on a small scale; but it was Germany, the world leader in chemistry, that had taken up chemical weapons with fervor. International treaties outlawed poison-gas shells in 1899, but Germany argued that gas canisters were still permissible. Either way, once deadly gases entered the field of war, gas shells were adopted by both sides. Within a year of Germany first using chlorine gas, in April 1915 at Ypres, chemical weapons had become a key part of the arsenal for both the Allied and Central Powers.


Stories of gas warfare still manage to shock and astonish us. If war is hell, the chemical attacks of World War I have come to seem worse than hell. These weapons rarely killed—yet they seeped through a soldier’s clothing, coated his body with burning blisters, and seared and sometimes blinded his eyes. Church saw all this firsthand.

Chemical weapons are remembered for the fear and suffering they brought to the battlefields, but they deserve just as potent a reputation for their transformation of civilian science. The United States had only experienced chemical weapons secondhand, through the reports of such men as Church. Yet thousands of miles from the front lines these weapons prompted Americans to mobilize a sprawling apparatus of laboratory research, factory production, and military training. Toxic gases became an urgent field of scientific inquiry, a thriving industry, and, in the minds of some, a necessary and even humane reality. Their impact on the home front persists to this day.


In early 1917 Church and another observer were sent back to Paris to attend a French course on asphyxiating gases. Their reports described the structure of each “gas service” created by France, Germany, and Britain. “Present warfare is so different from former fighting that the directive principles of organization have to be absolutely different,” wrote Church’s colleague Charles Flandin. “As regards gas, it seems to me that the organization ought to be less military than industrial.” It would need not only military prowess but also chemical, medical, and commercial expertise.

When the United States finally entered the war in April 1917, Church and Flandin’s reports laid the groundwork for what gradually became the Chemical Warfare Service (CWS). In accordance with the recommendations of the two observers, the first agency placed in charge wasn’t a military organization. Most of its high-ranking employees were engineers and chemists.

The Director

By February 1917 American entry into the war seemed inevitable. President Woodrow Wilson sent a request for support to U.S. government agencies. This request reached the desk of Van H. Manning, an inventive and stubborn man who directed the relatively new Bureau of Mines.

Manning immediately called a meeting of his staff. In the previous year his bureau had worked on such problems as the determination of moisture in coke, the installation of electric lighting in mines, and the prevention of coal-dust explosions. It had also organized rescue operations after major mine accidents. At first glance these seem like the domestic concerns of a civilian agency—hardly relevant to a world war. At the meeting, however, an engineer named George S. Rice suggested that the bureau could build on its experience with toxic mine gases to counter the poison gases deployed against Allied troops.

In a way mines were the trenches of the home front. They were cramped, claustrophobic, and often deadly, causing an average of 2,000 deaths annually between 1900 and 1910. Many miners died not from structure collapse but from poisonous gases that seeped out of the sediment or billowed from mine fires.

In a way mines were the trenches of the home front. They were cramped, claustrophobic, and often deadly, causing an average of 2,000 deaths annually between 1900 and 1910.

Manning wrote to the secretary of the interior with his offer: the Bureau of Mines could immediately assist the military in developing defenses against toxic gases. For several years researchers at the Bureau of Mines had been developing gas masks that successfully filtered toxic air through porous activated carbon, at least for a few hours. In an era when miners still carried canaries into coal mines, these masks represented advanced technology. Manning’s proposal was quickly forwarded to military leaders in Washington.

Two months later, on April 2, President Wilson asked Congress to declare war on Germany. The Bureau of Mines was immediately placed in charge of gas defense. The National Research Committee created a special Subcommittee on Noxious Gases to consolidate military, medical, and chemical expertise. These were the seeds of an unprecedented partnership: vast swaths of civilian science were being mobilized in the service of war.

The Academics

Three of Manning’s first recruits were chemists from the American Sheet and Tin Plate Company, the Massachusetts Institute of Technology, and Johns Hopkins University. He sent each one to a different part of the country to rally support. In only two months the Bureau of Mines obtained offers of material and research support from 118 chemists at 3 corporations, 3 government agencies, and 21 universities. Steadily they would be drawn into the war effort.

Because the bureau was still seeking laboratory space, chemists began with independent research at their home institutions. At the University of Michigan researchers studied the effects of mustard-gas poisoning. Yale University built a toxicology laboratory beneath the bleachers of its athletic field. Elsewhere, scientists experimented with gas-mask design, mass-production techniques, and the synthesis of new toxic chemicals.

Independent projects were difficult to manage, however, and Manning’s team soon accepted an offer of space from American University in Washington, D.C., in order to centralize research. In June the War Department and navy paid $175,000 to convert classrooms into laboratories. Chemists hired by the bureau began to arrive even before the space was complete. They started their work surrounded by the racket of carpenters, plumbers, and electricians.

All this unfolded while the military pursued two other essential tasks. If chemical weapons were unfamiliar to chemists, they were even more unfamiliar to soldiers. The Corps of Engineers advertised for a new military unit, the First Gas Regiment, based at Camp American University. They sought an initial cohort of 250 privates, 30 fighting chemists, and various technical recruits. “The time has gone by for any ethical discussion as to the propriety of using gas and flames against the enemy,” one ad insisted. “Their fire must be fought with hotter fire.”

The troops, meanwhile, would need a reliable source of weapons, gas masks, and protective clothing. The army’s Ordnance Department began contracting with corporations for the production of toxic chemicals. In Long Island City millions of gas masks were produced, largely by female workers. Meanwhile, in Edgewood, Maryland, just 50 miles from American University, the army built several airtight buildings for filling shells with gas. It centralized operations even further with a cluster of massive plants that synthesized toxic gases, from chlorine and phosgene to the infamous mustard gas.

Washington was now the hub of American chemical warfare efforts, and the Bureau of Mines was the leading civilian organization in poison-gas research. Decades before the mid-20th century concept of the “military-industrial complex” and a quarter-century before the more famous nuclear bomb project, federal funding had brought together hundreds of scientists and soldiers on the campus of American University. At the end of 1917 the expanded Bureau of Mines employed 277 civilians. A year after establishing operations on the campus the payroll would include more than 1,000 scientists and technicians.

The Germans

There was an irony to the chemical army being assembled in the United States. On almost all fronts it followed in the footsteps of German chemists.

Even before the outbreak of war German chemists were trying to produce a key military substance: synthetic nitrates. Nitrates were the raw material of explosives and fertilizers, and Germany’s supply was too limited for long-term warfare. Some of Germany’s best chemists joined the nitrate effort, including Fritz Haber.

By the beginning of 1915 Haber was leading Germany’s poison-gas research. Like the network of American chemists that developed a few years later, the German war effort unified industrial and academic chemistry. Haber ran an academic institute in Berlin, while the Bayer dye factories and the Hoechst Color Works helped mobilize the German dye industry for chemical warfare.

Dozens of top chemists eventually joined the German gas project. Proposals, such as Haber’s plan for weaponizing chlorine gas, were reviewed by Walther Nernst, a University of Berlin chemist, and Carl Duisberg, the managing director of Bayer. When the proposals were approved, Haber recruited a team of scientists that included several future Nobel laureates. Like the factories in Edgewood, Maryland, Bayer produced toxic chemicals, including mustard gas.

The similarities between the German and American gas projects were no accident. At the time, Germany was the world leader in chemistry, and the United States was reliant on German manpower and machines. As late as 1917 the American instrument maker Chester Fisher was importing lab equipment from Bavaria—and shipping it to poison-gas laboratories in France.

The German American

Ties between German and American chemistry were even tighter in the industrial sphere. Many of the United States’ prewar dyestuff and pharmaceutical suppliers were actually branches of German corporations. Americans who wanted a competitive education often traveled to German universities to study chemistry, while German chemists who sought new opportunities came to America. During the war, however, the United States subverted and harnessed the resources of its German competition.

American tactics are brought to life in the odd case of William Beckers, who was born in the Ruhr, the heart of German industry and coal production. Beckers earned a doctorate in chemistry, served in the German military, and was hired by Bayer. The company sent him to the United States in 1902, while he was still in his twenties.

In retrospect, Beckers seems a very fortunate man. After nine years he became an American citizen. He left Bayer, and in 1912 he founded the Beckers Aniline and Chemical Company. When the war began, German-based companies suddenly seemed suspicious. As a citizen of the United States, however, Beckers no longer worked for a German company.

Rather than appear a threat, he made himself an asset. In early 1916 he argued for tariff protection against German chemicals before the U.S. House Ways and Means Committee. That was the only way, he said, that the United States could overcome its reliance on Germany.

Later that year, in a speech to American textile producers, he warned his colleagues about German industrial strength. “The same basic raw materials are used for both the manufacture of explosives and dyestuffs,” he remarked. This fact was well-known among chemists at the time: dye factories in Europe had rapidly adapted to the needs of munitions production. Even in the practice of peace commercial chemists—such as the mining engineers of the Bureau of Mines—had unwittingly crafted tools for war. “We American chemists,” Beckers went on, making no mention of his German origins, “are not as experienced in the manufacture of dyes as our German colleagues, who have been making these products for the last half century.”

Six months after war was declared, suspicious American authorities gained the legal power to act against German companies. Congress passed the Trading with the Enemy Act, and a man named Mitchell Palmer was appointed Alien Property Custodian. Palmer’s office began receiving thousands of reports of enemy-held property. Factories and businesses owned by German nationals were seized by the government, along with thousands of valuable chemical patents. Beckers’s former employer, the American branch of Bayer, was seized. Many of its employees were even imprisoned at Fort Oglethorpe, Georgia, an internment camp that today has been largely forgotten.

World War I helped erode the advantages of German chemistry. When hostilities in Europe finally ended in 1918, the United States was producing four times as much poison gas as Germany. Palmer, perhaps recognizing that his wartime powers would soon wane, quickly disposed of confiscated holdings worth millions of dollars. Bayer was sold at a public auction on the company steps.

When hostilities in Europe finally ended in 1918, the United States was producing four times as much poison gas as Germany.

Yet even in the midst of anti-German fervor, William Beckers dodged the bullet thanks to his careful alignment with the American war effort. In 1917 his company merged with four others, the most important of which had also been founded by a German immigrant. The result—the National Aniline and Chemical Company—produced mustard gas for the CWS. Beckers retired to upstate New York in 1919 and lived another three decades as a rich man.

The Troops

Soldiers from the First Gas Regiment shipped out of Washington on Christmas Day, 1917. Their vessel retraced the winter journey of James Robb Church, the medical observer whose reports had set all this in motion two years before.

It was already late in the war when the regiment reached the front lines in March. Their hasty training had given them almost no experience in the actual deployment of poison gas, but they carried mortar launchers specially designed for the task. By this time chemical weapons had become ubiquitous, and millions of soldiers on both sides were ready to slide on gas masks at the shortest notice. But because American soldiers entered late in the war, they suffered a greater number of gas casualties—one-third of a total 200,000—than any other nation.

The regiment fought its largest battle in April 1918, when German forces fired an estimated 80,000 mustard-gas shells in the course of only two days. The American gas troops fired back, deploying thousands of phosgene shells and canisters in support of French and British infantry offensives. Despite such numbers, the amount of gas used on European battlefields never matched the scale of gas production at home.

Three years earlier, at the Second Battle of Ypres, Germany had first used mustard gas. But despite years of gas and conventional warfare, the Central Powers and the Allies were still fighting over the same patch of land. Some called the April offensive the Fourth Battle of Ypres.

The Armistice

While American troops adopted chemical weapons, American chemists were adopted into the military. Chemical production and research had been scaled up tremendously, and military leaders wanted to centralize the diverse efforts of the Bureau of Mines. Director Manning argued that civilian chemists worked best under civilian control, but after a drawn-out administrative battle President Wilson ultimately decided otherwise. In June 1918, 1,700 American chemists were transferred to the newly established Chemical Warfare Service of the Army Department. They had volunteered to help the military but ultimately became part of it.

The end of war came five months later, with a whimper rather than a bang. As a chaplain in the First Gas Regiment put it, “For long it was hard not to feel that we were simply passing through a lull between fights.”

The future of the CWS was in doubt. The regiment’s commanding officer wrote to his men, “Whether the Chemical Warfare Service will be continued in peace remains to be seen.” No matter what, he wanted them to know that their work would be remembered. “It will be the guiding star for such work in any future war, should, unfortunately, our country ever again have to enter upon one.”

Some scientists in Washington slipped back to their universities and corporations. Others went looking for new work. Only a tiny group remained in the employ of the government, and they waited to see whether the CWS would be disbanded. The weapons the CWS had spent years developing were routinely attacked in the public sphere as cruel and unethical.

In 1919 the general in charge of the CWS gathered a group of his former officers. Recognizing that their profession and perhaps the dignity of the work they had completed was now at stake, they decided to launch a national publicity campaign. “Contrary to general opinion,” remarked one prominent chemist, Charles Herty, during a speech, “gas warfare has not proved inhumane.” All weapons are by definition destructive, he argued—yet proposals to outlaw guns or explosives are never seriously discussed. “The League of Nations has met. It has not agreed that this new method of warfare should be abolished and so we stand today faced with the fact that this new method is going to be developed, and that is the significance of our Chemical Warfare Service to this nation.”

Though the campaign’s success was mixed, the CWS was never disbanded—simply adapted to new military needs. Chemical weapons were denounced and outlawed by many treaties after World War I. But the peacetime CWS launched a series of odd research projects designed to improve its reputation, many of which used the very same toxic chemicals synthesized during the war. Researchers tried to produce barnacle-repellent paint for the sides of ships. The CWS built a bizarre defense device for banks that released mustard gas when a safe was forced open. In 1924 the CWS even tried to cure President Calvin Coolidge’s cold by sealing him in a chamber with low doses of chlorine gas. “One of the ways in which the ravages of war are going to be offset,” said the general in charge of the civilian CWS, “is by making use in peace of the knowledge of those poisonous compounds gained in the war.”

To this day two of the best-known war poisons—phosgene and chlorine gas—are used in agriculture and water systems, respectively.

The most lasting of the CWS’s civilian contributions was the development of new pesticides. In the 1920s CWS researchers tested the usefulness of tear gas in exterminating rats and boll weevils. In the decades that followed, CWS researchers repurposed military planes and sprayers for pesticide research. After the agency changed its name in 1946 to the Chemical Corps—which remains a branch of the U.S. Army—former CWS members even helped popularize DDT.

To this day two of the best-known war poisons—phosgene and chlorine gas—are used in agriculture and water systems, respectively. Farmers prospered from the same sorts of chemicals that caused the suffering of so many soldiers, and chlorine gas is the most widely used water disinfectant in America.

Science transforms war, and war transforms science. Chemical weapons are infamous for the suffering they caused on the front lines of World War I—but their effects reached far past the trenches into American laboratories and German factories, and even into our lives today.