Fritz Haber: The Jewish Scientist Who Accidentally Murdered a Million Jews

On Holocaust Remembrance Day, when we honor the six million Jews killed, the story of Fritz Haber comes to mind. This brilliant Jewish scientist, who converted to Christianity, saved countless lives with his discoveries but unknowingly laid the groundwork for one of history’s darkest chapters. His invention of a gas for agriculture was twisted into a tool of mass destruction.

Here’s a look at Haber’s life and the haunting legacy he left behind.

Who Was Fritz Haber?

Born on December 9, 1868, in Breslau, Haber was a gifted chemist with a sharp mind and a lively personality. Friends described him as impulsive, quick thinking, and a captivating speaker who could talk about anything. Coming from a merchant family, he studied chemistry at the University of Berlin, earning his doctorate in 1894. As a Jew in Germany’s restrictive society, Haber faced barriers to advancement. To break through, he converted to Christianity, following a path taken by other Jewish intellectuals who believed patriotism and assimilation would lead to acceptance.

Haber’s career took off quickly. By 1906, he was a professor in Karlsruhe, and in 1910, he became head of an institute and professor at the University of Berlin. He joined Germany’s prestigious Prussian Academy of Sciences and earned a high salary. His greatest achievement was the Haber Bosch process, a method to produce ammonia from nitrogen in the air, essential for chemical fertilizers.

This breakthrough boosted food production worldwide, helping to reduce hunger. In Germany, it was called “making bread from the air,” and it earned Haber the Nobel Prize in Chemistry in 1918, a recognition of its immense value to agriculture and humanity.

The Dark Side of His Work

But Haber’s story has a grim side. During World War I, he became known as the “father of German chemical warfare.” He developed methods to use chlorine gas as a weapon, which caused the agonizing deaths of thousands of French soldiers by suffocation. Haber even supervised these experiments on the battlefield himself. His work on chemical weapons drew widespread public outrage and criticism from fellow scientists, many of whom called him a war criminal who deserved prison.

The consequences hit closer to home, too. His wife, Clara, also a converted Jew and a chemist, took her own life in front of their son after learning the deadly impact of Haber’s chemical weapons. Their son, Hermann, later died by suicide as well, adding to the personal tragedy surrounding Haber’s choices.

Haber’s institute, the Kaiser Wilhelm Institute for Physical Chemistry, also played a role in darker developments. Around 1915, it tackled pest control issues, like lice and warehouse insects. Under Haber’s leadership, the institute worked on chemical weapons and, after the war, shifted to pesticides. In 1917, it joined forces with the Degussa company to form a pest control committee, using hydrogen cyanide (known as Blauzäure) to kill lice.

In 1919, Haber helped found the German Pest Control Company, or Degesch, in Berlin to distribute gas based pesticides. While he left Degesch in 1920, his ammonia synthesis process set the stage for the creation of Zyklon B, the gas later used to murder over a million Jews, including Haber’s own people, in Nazi gas chambers.

A Tragic Turn Under the Nazis

Haber’s life took another painful twist when the Nazis rose to power in 1933. Despite his lifelong dedication to Germany and his contributions to its war efforts, Nazi race laws didn’t spare him. He was forced to fire all Jewish staff at his institute, then had to resign himself and flee the country. His belief that “in peacetime, a scientist belongs to the world, but in wartime, to his country” offered no protection. Haber wandered Europe, struggling to find an academic position, his reputation overshadowed by his past.

In a bittersweet twist, a lifeline came from his own Jewish community. Chemist Chaim Weizmann offered him a role leading the Ziv Institute in Rehovot, in what was then Palestine.

Near the end of his life, Haber began to reconnect with his Jewish roots and reflect on his choices. In letters to Weizmann, he called himself “bankrupt” and praised the Jewish settlement efforts in the land. Haber died in January 1934, his legacy a mix of brilliance and sorrow.

Zyklon B and Degesch’s Role

Degesch, the company Haber helped start, became infamous during the Holocaust. Founded in 1919 as a subsidiary of the pest control committee, it was backed by Haber’s institute and Degussa. By 1942, as the Nazis implemented the “Final Solution,” Zyklon B became a tool of mass murder in gas chambers at camps like Auschwitz, Majdanek, and Buchenwald. SS officer Karl Fritsch reportedly first tested it on Russian prisoners of war in August 1941. Distribution companies Testa and HeLi, sometimes directly from producers, supplied the camps.

Between 1942 and 1944, the camps received 56 tons of Zyklon B, about 8% of the 729 tons sold in Germany. That amount was enough to kill over a million people, mostly Jews, though the gas was also used for disinfection. The SS tightly controlled the gas chambers, with “doctors” overseeing the process.

After the war, company leaders faced justice. Testa’s owner Bruno Tesch and manager Karl Weinbacher were executed in 1946. Degesch’s Gerhard Friedrich Peters was convicted of aiding murder but acquitted on appeal. I.G. Farben, a major Degesch partner, was dismantled, with its assets split among companies like Bayer and Hoechst. Degesch itself continued, sold in 1986 to Detia Freyberg, and operates today as Detia Degesch GmbH.

A visit to Degesch’s website (now Detia Degesch) shows a historical timeline that skips over World War II, resuming with a “new beginning” afterward. A brief note condemns “serious crimes against humanity” but avoids mentioning Zyklon B or the genocide of Jews, a silence that feels striking given the company’s past.

A Story of Contradictions

Haber’s life is a painful reminder of how genius can lead to both progress and destruction. His work fed millions, transforming agriculture and earning him global acclaim. Yet, his innovations in chemical weapons and pest control were twisted into tools of unimaginable horror.

As a Jew who sought acceptance through conversion, his story carries an extra layer of tragedy, rejected by the country he served and linked to the suffering of his own people.

Haber's contributions saved lives, but his discoveries also enabled atrocities, leaving a mark that’s hard to reconcile.