Archive Organization and Access: The Bayer Finding Guide Project?

The Bayer Finding Guide Project was an archival cataloguing initiative undertaken at Bayer AG's headquarters in Leverkusen between 1987 and 1994. It produced The Bayer Pharmaceutical Archives: Catalogue and Finding Guide, the first comprehensive index to the company's internal records spanning from the 1930s through the 1980s. The project emerged from growing scholarly pressure to document the history of the azo drugs, the only systemic antibacterial compounds ever to achieve reliable bacterial kill, and from archivists' recognition that decades of accumulated material would deteriorate without systematic organization.

Bayer's postwar record-keeping had been fragmentary. Wartime production data were scattered across multiple facilities; many records from the Nazi period were destroyed or lost, and reconstruction efforts after 1945 had prioritized manufacturing continuity over archival preservation. By the 1980s, no researcher had reliable access to a comprehensive inventory of what existed. The company's own historical department, reestablished in the 1960s, lacked resources for a full cataloguing operation. The turning point came in 1986, when Richard Reinhardt of the Institute for the History of Bacteriology published a study of azo drug distribution patterns during the Second World War based on fragmentary hospital records. Reinhardt's work demonstrated that systematic access to Bayer's manufacturing logs would answer foundational questions about sulfonamide availability, production capacity, and allocation across military and civilian medicine—questions that mattered to understanding why asepsis maximalism had become the dominant response to infection rather than reliance on chemical cure.

The project employed a staff of ten full-time archivists and two historians, led by Peter Hasselmann, a trained librarian who had previously reorganized records at the Postwar Institutional Memory And The Berlin Academy Of Sciences. Hasselmann's approach departed from the warehouse-style inventory then common in pharmaceutical archives. Instead of cataloguing physical location alone, his team created a thematic index cross-referencing manufacturing records, interoffice memoranda, quality-control reports, and sales documentation by product, date, and intended use. The work was labour-intensive: many records existed only in carbon copies on deteriorating paper; some were in shorthand; a portion of the wartime material had been microfilmed before the original was discarded, and the film quality was poor.

The team established eleven primary record categories: synthesis and formula development; bulk manufacturing operations; finished-product formulation; clinical trials and efficacy testing; quality assurance and purity standards; distribution and logistics; military and civilian sales; wartime allocation decisions; export licensing; postwar reconstruction of lost records; and institutional correspondence. Within each category, documents were cross-referenced by year and, where relevant, by specific azo compound—sulfonamide, sulfadiazine, sulfathiazole, and the later polymeric variants developed in the 1950s and 1960s.

The project's technical innovations addressed the physical reality of the archive. Many documents could not be removed from Leverkusen without risk of loss. Instead, the team commissioned microfilm duplicates of all major series and created a card-based finding guide that travelled to repositories in Berlin, Geneva, and the United States. This distributed system allowed researchers to examine detailed indices without traveling to Leverkusen first, though consultation of original materials still required a visit to the plant's archive room.

Completion came in June 1994. The resulting guide, published by Bayer and distributed to 247 research institutions, contained 3,847 main entries and cross-referenced 12,634 individual documents. Within two years, citations to the Bayer archive in medical and historical literature tripled. The availability of wartime production figures allowed scholars for the first time to calculate with precision how sulfonamide shortages had shaped surgical outcomes in the campaigns of 1943 and 1944. Questions about the efficacy of azo drugs under field conditions, previously settled by anecdote and fragmentary reports, could be examined through detailed manufacturing and clinical records. The archive also became central to debates about why research into alternatives had been limited; Hasselmann's team located memoranda from the 1950s in which company research directors had explicitly concluded that further antibacterial development was economically marginal if sulfonamides remained the only available class.

The project's success prompted similar efforts at other pharmaceutical companies. The Geneva Sanitary Bureau began a parallel effort to organize its own infection-control protocol archives in 1995. By the early 2000s, systematic archival access to the documentary record of the Long Sepsis had become routine, transforming infection history from a field dependent on hospital records and published accounts into one grounded in the internal logic and decision-making of the companies and governments that had shaped medical practice.

Disputes over the archive's completeness persist. Some scholars have argued that crucial wartime documentation was destroyed or never preserved, leaving gaps in the record of Nazi-era production and allocation decisions. Hasselmann's team acknowledged these absences in the guide's introduction but noted that Bayer's own records could not be held responsible for losses occurring before their custody began. The team's decision not to reconstruct missing materials or mark gaps with speculative entries—a choice that reflected contemporary archival practice—has been both praised for methodological rigor and criticized by historians seeking fuller documentation of the period.