Haber, a known German nationalist, is also considered the "father of chemical warfare" for his years of pioneering work developing and weaponizing chlorine and other poisonous gases during World War I.

His work was later used, without his direct involvement,[10] to develop the Zyklon B pesticide used for the killing of more than 1 million Jews in gas chambers in the greater context of the Holocaust.

[13] Haber's father Siegfried was a well-known merchant in the town, who had founded his own business in dye pigments, paints and pharmaceuticals.

[12]: 19 In the summer of 1889, Haber was conscripted and left university to perform his one-year volunteer service in the Sixth Field Artillery Regiment.

[12]: 30–31 Haber had received a PhD in chemistry by this time, but his father required him to take handwriting courses and become a salesman to learn more about the company.

[12]: 32  During his time in Jena, Haber converted from Judaism to Lutheranism, possibly in an attempt to improve his chances of getting a better academic or military position.

[12]: 40 Haber was appointed a Privatdozent in Bunte's institute, taking on teaching duties related to the area of dye technology, and continuing to work on the combustion of gases.

Haber's 1898 book Grundriss der technischen Elektrochemie auf theoretischer Grundlage (Outline of technical electrochemistry based on theoretical foundations) attracted considerable attention, particularly his work on the reduction of nitrobenzene.

[12]: 61 During his time at University of Karlsruhe from 1894 to 1911, Haber and his assistant Robert Le Rossignol invented the Haber–Bosch process, which is the catalytic formation of ammonia from hydrogen and atmospheric nitrogen under conditions of high temperature and pressure.

Nitrogen bacteria teach us that Nature, with her sophisticated forms of the chemistry of living matter, still understands and utilizes methods which we do not as yet know how to imitate.

[25] Haber played a major role in the development of the non-ballistic use of chemical warfare in World War I, in spite of the proscription of their use in shells by the Hague Convention of 1907 (to which Germany was a signatory).

[12]: 133  In addition to leading the teams developing chlorine gas and other deadly gases for use in trench warfare,[26] Haber was on hand personally when it was first released by the German military at the Second Battle of Ypres (22 April to 25 May 1915) in Belgium.

A special troop was formed for gas warfare (Pioneer Regiments 35 and 36) under the command of Otto Peterson, with Haber and Friedrich Kerschbaum as advisors.

Future Nobel laureates James Franck, Gustav Hertz, and Otto Hahn served as gas troops in Haber's unit.

[12]: 136–138  In 1914 and 1915, before the Second Battle of Ypres, Haber's unit investigated reports that the French had deployed Turpinite, a supposed chemical weapon, against German soldiers.

[34] Haber received much criticism for his involvement in the development of chemical weapons in pre-World War II Germany, both from contemporaries, especially Albert Einstein, and from modern-day scientists.

[12]: 169 During the 1920s, scientists working at Haber's institute developed the cyanide gas formulation Zyklon A, which was used as an insecticide, especially as a fumigant in grain stores.

[37] From 1919 to 1925, in response to a request made by German ambassador Wilhelm Solf to Japan for Japanese support for German scholars in times of financial hardship, a Japanese businessman named Hoshi Hajime, the president of Hoshi Pharmaceutical Company, donated two million Reichsmark to the Kaiser Wilhelm Society as the 'Japan Fund' (Hoshi-Ausschuss).

[38] In the 1920s, Haber searched exhaustively for a method to extract gold from sea water, and published a number of scientific papers on the subject.

The directorship of the Kaiser Wilhelm Institute for Physical and Electrochemistry was given to the Jew, F. Haber, the nephew of the big-time Jewish profiteer Koppel".

)[12]: 277–280  Haber was stunned by these developments, since he assumed that his conversion to Christianity and his services to the state during World War I should have made him a German patriot.

According to this view, her suicide may have been in part a response to Haber's having personally overseen the first successful use of chlorine gas during the Second Battle of Ypres, resulting in over 67,000 casualties.

When Germany invaded France during World War II, Hermann and his wife and three daughters escaped internment on a French ship travelling from Marseilles to the Caribbean.

[12]: 182–183  His oldest daughter, Claire, committed suicide in 1949; also a chemist, she had been told her research into an antidote for the effects of chlorine gas was being set aside, as work on the atomic bomb was taking precedence.

Several members of Haber's extended family died in Nazi concentration camps, including his half-sister Frieda's daughter, Hilde Glücksmann, her husband, and their two children.

Brigadier Harold Hartley, Sir William Jackson Pope and Frederick G. Donnan arranged for Haber to be officially invited to Cambridge, England.

Thiessen describes Haber as a tragic figure who strives unsuccessfully throughout his life to evade both his Jewish ancestry and the moral implications of his scientific contributions.

After Hitler's rise to power, the government forced Haber to resign from his professorship and research jobs because he was Jewish.The second play was titled The Greater Good and was first broadcast on 23 October 2008.

It explored his work on chemical warfare during World War I and the strain it put on his wife Clara (Lesley Sharp), concluding with her suicide and its cover-up by the authorities.

[71] Haber's life and relationship to Albert Einstein was portrayed in Genius which aired on National Geographic Channel from 25 April to 27 June 2017.