DOHSBase Knowledge Base
Background articles on limit values, kick-off values, substance classification and the historical development of DOHSBase
The DOHSBase Knowledge Base is a collection of background articles for occupational hygienists, safety professionals and anyone working with chemical exposure limits. The articles explain the concepts, sources and methods underpinning DOHSBase Online: from statutory limit values and their hierarchy, through kick-off values for substances without formal OELs, to GHS/CLP classification and the historical development of the database itself. All available articles are listed below.
Occupational Exposure Limits
Limit-Value Hierarchy: Which OEL Takes Precedence?
Understanding the DOHSBase limit value hierarchy
Occupational Exposure Limits: TWA, STEL, Ceiling & Biological Limits
Legal limit values, 8-hour TWA, STEL, ceiling and biological exposure limits for hazardous substances at work
The Methodological History of DOHSBase: from 1992 Diskette to Limit-Value Hierarchy
How the DOHSBase methodology evolved since 1992: NVvA brochure, TOX/TIX/RAS (2006), SER decision scheme (2007), and today's hierarchy
TWA, STEL and ceiling limit: the three types of occupational exposure limit compared
The difference between the 8-hour time-weighted average, the short-term exposure limit (STEL) and the ceiling limit, and when each one applies.
Kick-off Values
Hazard banding methodologies compared: COSHH, EMKG, IFA, ECETOC and kick-off
Comparing five hazard banding methodologies on origin, output, validation and regulatory standing
Kick-Off Values: Exposure Benchmarks for Substances Without OELs
A short introduction — what kick-off values are, why they exist, and how to use them
Kick-Off Values: How They Are Calculated and Why They Work
The peer-reviewed methodology behind 100,000+ exposure benchmarks for substances without formal limits
DOHSBase Compare
DOHSBase Compare: methodology and application
An overview of the TOX, TIX and RAS scores, EN 689 compliance testing and the scientific validation behind DOHSBase Compare
DOHSBase methodology: scientific validation and regulatory recognition
How the DOHSBase methodology is peer-reviewed, how it compares to international hazard-banding systems, and why the Dutch Labour Inspectorate names it as an acceptable source for private OELs
EN 689 compliance assessment: testing TWA measurements against OELs with UTL statistics
How Upper Tolerance Limit with Monte Carlo simulation incorporates measurement uncertainty into compliance verdicts — implemented in DOHSBase Online
Risk-first vs disease-first: where OELs, DNELs and kick-off values fit in proactive substance screening
How the RIVM risk-first programme reframes occupational chemical safety, and where curated hazard and exposure data fits in
TOX, TIX and RAS score: the methodology behind DOHSBase Compare
How DOHSBase Compare ranks substances by health risk — published in the NVvA Newsletter of April 2006, and still the calculation core in 2026
Substance Classification
Australian GHS Classifications
GHS classification data from Australia in DOHSBase
CMR Substances: A Complete Guide for Occupational Hygienists
Carcinogenic, mutagenic, and reprotoxic substances — classification, obligations, and data sources
DNEL vs OEL: Understanding the Difference
Two exposure benchmarks, different origins, complementary roles
GHS Hazard Pictograms: Complete Reference Guide
All 9 GHS/CLP pictograms explained for occupational health professionals
H-Statements: Complete Reference for Occupational Hygienists
Understanding hazard statements under GHS/CLP and their role in risk assessment
How to Find and Apply a DNEL: A Step-by-Step Guide
From 'no legal OEL exists' to a defensible exposure benchmark, in six steps
Substance Classification: hazard classification of chemicals
An overview of GHS/CLP classification, H-statements, CMR categories, SVHC and the sources classifications rest on
SVHC and the REACH Candidate List: What Occupational Hygienists Need to Know
Understanding Substances of Very High Concern and their workplace implications
Why a substance has hazard classifications beyond the harmonised list — and your duty to assess every source
The legal obligation under CLP and the Dutch Working Conditions Decree to evaluate all classification sources, explained using xylene (H361d).
Other articles
Choosing sampling methods for a substance: all methods and methods per limit value
Why the right air sampling method depends on the limit value you are assessing against, and how to find both all methods for a substance and the methods per limit value in DOHSBase Online.
DOHSBase in the Literature
External publications and sector arbocatalogi that use DOHSBase as a source or working method
DOHSBase Capabilities
Overview of the functionalities in DOHSBase