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Summary: To assess a Belgian workplace you need a limit value per substance, and as in the Netherlands there is not one limit value but a whole landscape. For legal compliance the first source is the Belgian statutory limit value from the Codex on well-being at work, book VI, title 1 — specifically the list in annex VI.1-1. For actual health protection you look at the purely health-based values — but this is where the Belgian difference lies: Belgium has no national scientific committee that derives health-based limit values itself (no equivalent of the Dutch Gezondheidsraad or the German DFG MAK Commission), so that underpinning comes by definition from outside Belgium (European RAC/SCOEL values, the Dutch Gezondheidsraad, the German DFG MAK, the ACGIH). For substances with no formal limit value you use a DNEL or, if that is missing too, a kick-off value. This piece walks that decision path, with the Belgian source and what to watch for at each step.
For the Belgian workplace. The concrete sources and legal references in this guide — the Codex, book VI, the FPS Employment — apply to Belgium. The approach itself, choose the best available limit value per substance according to the quality hierarchy, is universal and identical to the one for the Dutch workplace; only the national sources and legal references differ. For anyone working on both sides of the border, that difference is exactly the point.
The practical question in an exposure assessment is almost never “what is the limit value of this substance?”, but “which limit value do I use, from which source, and how good is it?” In Belgium there is an extra layer: the statutory value is a Belgian matter, but the health-based underpinning comes from abroad. That makes the distinction between “do I meet Belgian law?” and “am I really protecting the worker?” even more explicit in Belgium than in the Netherlands.
A terminology bridge up front: agens = substance
Belgian regulation consistently speaks of an agens (plural agentia, “agent”) where English and Dutch practice would say substance/stof. It means the same thing. The Codex book and annex titles carry that term (“chemical agents”, “carcinogenic … agents”), so anyone searching the Belgian texts for “substance” alone will miss most of the regulation. In this guide we say substance in our own prose and agents/agentia where we quote a Belgian legal category directly.
The decision path: which value do you use?
1. Is there a statutory limit value? → the Codex, book VI, title 1
For legal compliance with Belgian well-being legislation the statutory limit value governs. The binding source is the list of limit values for exposure to chemical agents, annex VI.1-1 to book VI, title 1 of the Codex on well-being at work, maintained by the FPS Employment, Labour and Social Dialogue. If the substance is listed there with a limit value, that is the value the Belgian workplace must at least meet.
For each substance the list gives the EINECS number, the CAS number, the name, the eight-hour limit value (time-weighted average) in ppm and mg/m³, the short-term value for normally fifteen minutes in ppm and mg/m³, and an additional classification column whose notations matter in practice:
| Notation | Meaning |
|---|---|
| A | Asphyxiant gas or vapour: not toxic in itself, but displaces oxygen. Below 17 to 18 vol% asphyxiation occurs without prior warning. |
| D | Uptake through the skin, mucous membranes or eyes can contribute substantially to the body burden. The Belgian equivalent of the Dutch H notation (skin). |
| F | Exposure is in fibre form; the concentration is expressed in fibres per volume, not mg/m³. |
| M | Above the limit value irritation occurs or acute poisoning threatens. Functions in practice as a ceiling-type requirement: the work process must be designed so the value is never exceeded. |
| VI.2 | The substance falls under title 2 of book VI (CMR and endocrine disruptors). See step 3. |
What to watch for: the Belgian list puts announced changes inline in the table, with the effective date. For acrylonitrile, for instance, both the value up to and the value from 5 April 2026 sit in the same cell, and there are values that only take effect in 2027. So for a Belgian substance check not only what the value is now, but also whether a stricter value with a future date is coming.
2. No statutory value, or extra protection needed? → health-based advice from outside Belgium
If there is no statutory limit value, or you want to test whether the Belgian value protects adequately, you look at the purely health-based advice. This is where Belgium differs from the Netherlands. Where a Dutch assessor can turn to the Gezondheidsraad (committee DECOS) for a national, purely health-based value, no such scientific committee exists in Belgium. Belgium does have a national advisory body — the High Council for Prevention and Protection at Work — but it is a social-dialogue body advising on the draft decrees (feasibility, support), not a committee that derives the health-based value itself. Belgium does not do that health-based derivation nationally; the chain therefore starts a level up:
- At European level, the opinions of RAC and the former SCOEL (via ECHA);
- From the neighbouring countries, the Dutch Gezondheidsraad (DECOS) and the German DFG MAK values;
- Internationally, the ACGIH TLVs (US).
A convenient way to see those international values side by side is the GESTIS database of international limit values from the German IFA/DGUV.
What to watch for: an advisory value is not a statutory limit. Use it to assess and substantiate, not as proof of compliance. And because the underpinning comes from abroad by definition, transparency about provenance matters all the more here.
3. Does the substance fall under the strict CMR regime? → book VI, title 2
This is the step where Belgium diverges most clearly. The question “does this substance fall under the strict CMR regime, with its substitution duty, exposure registration and closed systems?” is answered in Belgium by title 2 of book VI, and the limit-values list flags it with the notation VI.2. That notation has two variants, and the difference is set out explicitly in the legend:
- VI.2 — the substance falls under title 2 on the basis of its harmonised classification (Annex VI of the CLP Regulation);
- VI.2 (N) — the substance falls under title 2 on the basis of its notified classification (the classification companies have themselves notified to ECHA’s C&L Inventory).
A substantial share of the VI.2 entries are of the (N) type. The consequence: a substance can fall within the Belgian CMR regime while having no harmonised CMR classification — and so would not appear as CMR on a list that follows only the harmonised classification. On top of that, Belgian title 2 explicitly also covers agents with endocrine-disrupting properties. For the Dutch system by comparison, see CMR substances.
4. No value at all? → DNEL and kick-off values
For substances with no official limit value there is often a DNEL (Derived No-Effect Level) available through the REACH registration — usable as an interim step, with the familiar limitations (derived in a product-safety context, variable quality); see DNEL versus limit value. If a DNEL is missing too, you fall back on hazard banding: a kick-off value as a conservative starting point, derived from the distribution of existing limit values for substances with a comparable hazard classification. These layers are not Belgian or Dutch in nature — they apply across borders.
Two questions, two kinds of value — the Belgian version
The trap is to treat “the limit value” as a single number. For a Belgian workplace the two questions look like this:
| Your question | Which value | Where |
|---|---|---|
| Do I meet Belgian law? | Statutory limit value | Codex book VI, annex VI.1-1 (FPS Employment) |
| Am I really protecting the worker? | Health-based advisory value (non-Belgian) | RAC/SCOEL, NL Gezondheidsraad, DFG, ACGIH — via e.g. GESTIS |
| Does the substance fall under the strict CMR regime? | Title 2 / VI.2 (incl. VI.2 (N)) | Codex book VI, title 2 |
| No OEL — what do I use then? | DNEL/DMEL, otherwise kick-off value | REACH dossier; DOHSBase |
| Which value takes priority if there are several? | See the precedence rule | Hierarchy of limit values |
The role of DOHSBase
Looking all these sources up separately — the Codex table, the European and neighbour advice, the REACH DNELs, the kick-off values — takes time and is error-prone, and for Belgium there is the added hurdle that the health-based underpinning has to come from several foreign sources. DOHSBase Online brings this together: the Belgian Codex values and the CMR classification of title 2 are included, and the BE profile tunes the source order to Belgium. That order runs from near to far — Belgium → Europe → immediate neighbours (the Netherlands, France, Germany) → the rest of Europe → everywhere else — and is walked twice: once for the legal values and once for the health-based ones. Because Belgium does not derive health-based limit values itself, that second chain starts at European level. So for each substance you see both the binding Belgian value and the best available health-based value, with the provenance shown alongside. The background to this release is in the blog post Belgian limit values in DOHSBase.
The Belgian data is in fact visible from all European profiles, including the Dutch one; only the BE profile itself, with the Belgian source order, is switched over on request through support in the portal.
Frequently asked questions
Why does Belgium not derive health-based limit values itself? Belgium has not set up a national scientific committee that, like the Dutch Gezondheidsraad (DECOS) or the German DFG MAK Commission, derives health-based advisory values from toxicological assessment itself. The statutory limit values are set nationally (in the Codex, by royal decree, with the High Council for Prevention and Protection at Work advising on feasibility), but the underlying health-based value relies on European and foreign advice.
Which source is binding under Belgian law? The list in annex VI.1-1 to book VI, title 1 of the Codex on well-being at work (FPS Employment). Those are the binding Belgian limit values.
Can the same substance have a different limit value in Belgium and the Netherlands? Yes. The two countries set their statutory values separately and have not harmonised them. Assess a Belgian workplace against the Belgian value, even if you know the Dutch one.
What is the difference between VI.2 and VI.2 (N)? Both mean the substance falls under the Belgian CMR regime (title 2). VI.2 rests on the harmonised CLP classification, VI.2 (N) on the notified classification in ECHA’s C&L Inventory. The (N) variant makes the Belgian CMR scope broader than the harmonised list alone.
Want the Belgian and international values per substance on one screen — the statutory Codex value, the health-based values and the CMR classification, each with its source and ranked by quality? See DOHSBase Online or create a free trial account and look up ten substances at no cost.