Perhaps one of the most fascinating, if lesser known, stories about the Japanese American wartime experience is that of the Manzanar Guayule Lab. In the weeks leading up to the incarceration of Japanese Americans in 1942, several scientists at the California Institute of Technology decided to start a research project at the Manzanar concentration camp (then known as Owens Valley Reception Center) studying the guayule plant—a desert shrub that when processed could produce a rubber latex similar to Hevea rubber. The study was initially proposed by Robert Emerson, a Quaker and a professor at Caltech, as a way to support his research assistant Shimpe “Morgenlander” Nishimura. It then grew into a larger project studying potential industrial applications of guayule.
Between 1942 and 1945, a team of Japanese American scientists, including Kenzie Nozaki and Masuo Kodani, worked at Manzanar to develop new methods of cultivating and extracting rubber from the guayule shrub. As I previously wrote in a journal article for Southern California Quarterly, the staff of the guayule project found ways to improve the extraction of guayule and to breed the plant so as to increase its yields. These findings were published in three scientific journals during and after the war, with each article discussing the nature of their work within the confines of Manzanar. To this day, the legacy of the guayule project can still be seen at Manzanar in the form of several shrubs planted at the historic site by Frank Akira Kageyama, one of several nurserymen who worked on the project.
Today, however, I would like to spotlight the contributions of Frank Nobuo Hirosawa, a chemist who got his start working on the guayule project, then continued his scientific research after the war. Working at the Manzanar lab, Hirosawa provided expert guidance on the chemical refinement of guayule and contributed to the scholarly literature produced by the scientists. While Hirosawa continued his scientific research on guayule after the war, he is perhaps more famous for his work with Arie Jan Haagen-Smit at the California Institute of Technology. There the two discovered the effects of smog on human health, resulting in the creation of the California Air Resources Board and the establishment of clean air standards in California and other places.
Frank Nobuo Hirosawa was born on September 4, 1915 in Seattle, Washington, to Kotaro and Natsu Hirosawa. His family originally came from Iwakuni, a city south of Hiroshima. He travelled frequently with his family to Japan during his childhood; according to the War Relocation Authority records, he spent 11 years in Japan for schooling, making him a kibei. At the age of 21, Hirosawa moved to Japan, where he spent the next three years. During his stay he studied at Ryojun Institute of Technology at Port Arthur, a city in the Japanese puppet state of Manchukuo (Manchuria). There he experimented with various synthetic rubber sources, using the poinsettia plant. He graduated with a degree in chemistry in 1935, and subsequently returned to Seattle. He enrolled in graduate courses in chemistry at the University of Washington, though he never completed his degree.
Hirosawa became active with the Japanese American Citizens League, and even participated in an art contest to design the JACL’s convention program for 1936. His submission received an honorable mention, while Tomio Itabashi of Auburn, Washington, won the contest.
He returned to the United States in 1938 and settled in Los Angeles. In November 1938, Hirosawa ran for the position of auditor in the JACL Los Angeles chapter. The Rafu Shimpo identified him as one of several kibei active in the organization.
After returning to Los Angeles, Hirosawa struggled to find work as a scientist. He instead found employment as an assistant to the actor Charlie Chaplin—one of several Japanese Americans who worked as staff at the actor’s mansion. As of March 1942, his address was listed as 1120 San Ysidro Drive in Beverly Hills, a house located next to the Chaplin residence.
The events after Pearl Harbor on December 7, 1941 changed the course of Hirosawa’s life. On March 31, 1942, just days before reporting to the Army-run Santa Anita detention center, Hirosawa married his sweetheart Sachiko Shimbo—one of many couples who married before embarking on the uncertain journey to camp. Hirosawa and his family then reported for detention at Santa Anita detention center, where they were held from April to June 1942. The Army would have likely sent the Hirosawas to Heart Mountain concentration camp in Wyoming like other Santa Anitans, but Robert Emerson, a botanist and professor at the California Institute of Technology, asked that Hoirosawa be sent to Manzanar to join the lab he had organized with Shimpe Morgenlander Nishimura. Before leaving Santa Anita, Hirosawa told the staff of the camp’s newspaper The Santa Anita Pacemaker, “If guayule is successfully raised at Manzanar, the Japanese evacuees from the West Coast can utilize their talent in worthwhile work.”
The Hirosawas left for Manzanar on June 9, 1942. One confined there, they lived at Block 31-10-3. At Manzanar, Hirosawa put his chemistry skills to use. Aside from his work at the guayule lab, Hirosawa also worked as Manzanar’s chemist for sewage and sanitation. Robert Emerson also advised Project Director Ralph Merritt to employ Hirosawa as a science teacher in the adult education department.
The guayule team soon developed a process by which the guayule shrub could be shredded and then filtered in a chemical solution to produce latex rubber. Once the guayule grindings were removed from a processor (engineered using old car parts), the scientists submerged the plant’s particles in a solution where latex rubber surfaced at the top. After washing out excess debris, the scientists found ways to mold the rubber into various products. As a part of the lab, Hirosawa developed the double solvent used to extract rubber from the shredded guayule plant.
Along with other scientists, Hirosawa assisted in the publicizing of the guayule project. On November 13, 1943, Hirosawa and Masuo Kodani, a lab physicist, gave a talk to the people of Manzanar about their work on guayule and its potential uses. The guayule lab successfully developed several products using their rubber, such as spatulas and stoppers for the mess hall, to show to the inmates during presentations.
Hirosawa became the “face” of the Manzanar Guayule Project once Dorothea Lange and Ansel Adams each photographed him at work. Lange photographed Hirosawa along with several other scientists, in July 1942, during the early days of the guayule project. Ansel Adams then made Hirosawa famous when he took a series of photos during his October 1943 visit to Manzanar, showing Hirosawa in the lab extracting guayule from the solvent. Adams depicted Hirosawa as a loyal American scientist contributing his research to the war effort, like the various nisei soldiers whom he photographed at Manzanar. Adams’s photos of Hirosawa later appeared in his 1944 book Born Free and Equal, which included Adams’s Manzanar photos along with an accompanying essay praising the loyalty of Japanese Americans.
While at Manzanar, Frank and Sachiko Hirosawa had two children: a daughter, Julia Sayako, born on February 1, 1943, and a son, Ronald, born in July 1944. The Hirosawas left Manzanar on November 13, 1945 for Chicago, Illinois, but soon returned to Los Angeles, where the family settled in the Boyle Heights neighborhood. The final achievement of the guayule lab was the publication of three academic articles that demonstrated how guayule could be bred to produce more rubber and how Hirosawa’s techniques extracted rubber from the plant. Hirosawa collaborated with Dr. Robert Emerson and Shimpe Morgenlander Nishimura on an article outlining their extraction methods, which appeared in the November 1947 issue of the journal Industrial and Engineering Chemistry.
After the war, Hirosawa followed up on his work at the Manzanar Guayule lab by working at a lab run by Desert Rubber Inc. at Beaumont, California. Desert Rubber Inc. was founded by Hugh Anderson, a Quaker civil rights activist and supporter of the Manzanar Guayule project, and Frank Kuwahara, the head of Poston’s guayule farm, both of whom believed in the potential of guayule as a replacement to Hevea Rubber. Anderson and Kuwahara hired Hirosawa to be their Research Director of Extraction and Purification of Guayule Rubber. With a $250,000 contract from the Wrigley Chewing Gum, Anderson and Kuwahara supported many of the Manzanar scientists after the war by providing employment. The Rafu Shimpo reported in their December 21, 1946 issue on the efforts of Hirosawa and other guayule scientists to synthesize guayule for Wrigley Chewing Gum, to replace chiclets. Although Wrigley eventually backed out of the contract, Hirosawa, the Manzanar scientists, and Hugh Anderson remained steadfast in their belief that guayule could be an excellent source of rubber.
Starting in 1947, Hirosawa embarked on a graduate degree in Advanced Organic Chemistry at the California Institute of Technology. In order to help support his family and his studies, in 1948 Hirosawa took a job with the Los Angeles-based rubber company Coast Pro-Seal and Manufacturing Company. The lab employed several nurserymen from Los Angeles, such as horticulturalist Frank Akira Kageyama, who nurtured the guayule seedlings under the direction of the scientists. As part of his work for the company, Hirosawa developed various liquid polymers for industrial purposes, such as new epoxy sealants for fuel tanks that could withstand high temperatures from jet fuel. Hirosawa’s research intrigued the United States Air Force, which applied Hirosawa’s sealants to the fuel tanks on their jet aircraft.
In addition to his interest in rubber, Hirosawa also began contributing during this time to studies on air pollution. While at Cal Tech, Hirosawa became the lab assistant to famed scientist Arie Jan Haagen-Smit. In 1948, Haagen-Smit had begun studying the negative effects of smog upon Los Angeles’s air quality for the city’s Air Pollution Control District. Over the course of several years of research, Haagen-Smit discovered that emissions from automobiles and petroleum refineries contributed extensively to poor air quality in Los Angeles and damaged human lungs. In 1950, Hirosawa began working with Haagen-Smit as his assistant for several studies on air pollution. As part of the experiment, Haagen-Smit and Hirosawa studied fractionation caused by smog—the process by which materials decay due to carbon emissions.
Here, Hirosawa’s rubber expertise came into play: using rubber straps as test samples, Haagen-Smit tested the rubber to identify the extent of ground ozone caused by smog. In cases when smog reached its peak during the afternoon (and rush-hour traffic), the rubber reacted with the ozone and started to crack. The research established the need for better air quality control in Los Angeles. Both Hirosawa and Haagen-Smit were pictured on the cover of Cal Tech’s magazine Engineering and Research in May 1952, with Haagen-Smit’s accompanying article titled “Smog Research Pays Off.” Haagen-Smit used their findings to lobby the California government to create the California Air Resources Board. In recognition of his efforts, Haagen-Smit was appointed the first president of the board in 1968.
Ironically, it was an article about wine on which Hirosawa collaborated with Haagen-Smit that would become their most cited work. The article discussed the volatile compounds found in Zinfandel grapes during the winemaking process. (Before studying smog, Haagen-Smit had initially researched the compounds found in pineapples!)
Hirosawa stopped his graduate work in 1952. After working for several years with Coast Pro-Seal, Hirosawa found employment with Furane Plastics, Inc. as their chief chemist and director of research. When he retired from the company in 1970, he became a part-time consultant. His son Ronald worked as his correspondence secretary.
In his spare time, Hirosawa enjoyed listening to classical music and repairing electronics. He won $15 in the Los Angeles Times’s Name of Games contest in 1955 (unfortunately, another Angeleno took home a $10,000 prize in the same contest). He also worked with Boy Scout Troop 197. His wife Sachiko served on several schoolboards, such as the Hollenbeck Jr. High School PTA.
Frank Nobuo Hirosawa died on August 31, 1987. As one of several scientists who contributed to the groundbreaking research on guayule at Manzanar and smog control at Caltech, Hirosawa leaves behind an important scientific legacy.
© 2025 Jonathan van Harmelen
