From 1,000 to 325,000 Substances: The 1994 Article That Introduced DOHS-Base

In 1994, a two-page article appeared in Arbeidsomstandigheden — the leading Dutch journal for occupational health and safety at the time. Written by Leendert Meijers of TNO and Theo Scheffers, it announced the release of DOHS-Base 2.0: a database of chemical substance information for occupational hygienists, now extended with company-specific limit values (bedrijfsgrenswaarden).

The article, titled “DOHS-Base 2.0 opengesteld voor bedrijfsgrenswaarden”, was published in volume 70, number 3 (pages 149-150). We recently rediscovered this publication on the TNO publications archive, and it provides a fascinating window into the origins of what is now DOHSBase Online.

DOHS-Base 1.0: February 1992

The article reveals that DOHS-Base 1.0 was released in February 1992 — confirming DOHSBase’s founding year. The initial version was developed in collaboration with the NVvA’s Werkgroep Grenswaarden en Meetmethoden (Working Group on Limit Values and Measurement Methods). It was presented on CD-ROM — the standard distribution medium of the early 1990s.

Even in that first release, the core mission was clear: bring together scattered occupational exposure data into a single, structured, searchable resource.

What DOHS-Base 2.0 Contained

By the time version 2.0 was announced in 1994, the database had grown to contain approximately 1,000 chemical substances with:

MAC values (Maximaal Aanvaarde Concentratie) — the Dutch occupational exposure limits of the era
Company-specific limit values (bedrijfsgrenswaarden) — a new addition in version 2.0
Measurement methods for workplace air monitoring
CAS and EC numbers for substance identification
Data sourced from Dutch national standards (Staatscourant, P-145 lists) as well as international references

The article emphasized that DOHS-Base drew from both Dutch and international sources, with coverage of limit values from multiple countries — a design principle that remains central to DOHSBase today.

The Problem It Solved

Meijers and Scheffers described a challenge that occupational hygienists of the 1990s will recognize — and that still exists today without tools like DOHSBase:

“Het beheersen van belastende factoren is een dynamisch proces met terugkoppelingen.”

Managing exposure factors is a dynamic process with feedback loops. Limit values change, new substances enter the workplace, measurement methods evolve. Without a centralized, maintained database, professionals had to consult dozens of separate publications, regulatory lists, and scientific reports for every single substance assessment.

The article noted that even by 1994, Dutch companies struggled to maintain proper documentation of workplace exposure standards. The accompanying photograph — captioned “Nederlandse fabrieken hebben van enkele honderden stoffen goed gedocumenteerde bedrijfsnormen” — showed that only a fraction of substances in use had well-documented company standards.

The People Behind It

The 1994 article was co-authored by:

Leendert Meijers — advisor at TNO (the Netherlands Organisation for Applied Scientific Research), bringing the scientific and institutional backing
Theo Scheffers — who would go on to lead DOHSBase for over three decades and remains active today as one of its principal occupational hygienists

The update to version 2.0 was presented by Marius Heijster, then director-general of the Arbeidsinspectie (Labour Inspectorate) — an early sign of the regulatory recognition that would later extend to DOHSBase’s kick-off values methodology in 2012.