This post covers two regions at very different stages of odour regulation. Africa’s frameworks are mostly young, general-purpose environmental laws that mention odour in passing rather than regulate it in depth — several are still in draft form years after being proposed. Europe, by contrast, has some of the world’s oldest and most technically detailed odour regimes — but even here, the picture most published reviews describe is now out of date, because European Union law itself changed in a way that matters directly to odour in 2024.

A shared starting point

The five African frameworks below all share a family resemblance worth naming up front: most name odour explicitly within a broader environmental or air-quality act, but none has a binding odour-concentration standard in odour units — Nigeria comes closest with pollutant-specific ambient limits; elsewhere the details are left to future regulations, ministerial notices, or case-by-case enforcement. That’s not necessarily a design flaw; it’s a common and defensible first stage for a young regulatory system, and in several cases (Uganda, Mauritius) the enabling legal language is already in place for numeric standards to be added later without needing entirely new legislation. What’s largely still missing across the continent is the second stage — the actual technical standards, accredited measurement capacity, and enforcement funding that turn an enabling clause into something a regulator can act on. That’s a genuinely useful parallel to keep in mind heading into the final post of this series, since India’s own starting point looks strikingly similar to several of these African frameworks.

Africa

Uganda

Regulatory mechanism: ambient air quality standards in development, with odour named as one parameter (not yet in force).

Kampala was selected as one of ten cities worldwide to pilot a community-engagement-based approach to odour pollution (the D-NOSES pilot), and that experience has fed into Uganda’s first dedicated Air Quality Regulations and Standards, now being developed jointly by the National Environmental Management Authority and the Kampala Capital City Authority. This follows the 2019 National Environment Act, which replaced a 24-year-old predecessor law. The draft standards would set health-based ambient air quality requirements, cover indoor air and worker protection, restrict emissions from industrial sources and vehicles, and establish a permitting and compliance system — odour is explicitly named as one of the parameters to be regulated once these are finalised.

Mauritius

Regulatory mechanism: general enabling law (Environment Act 2024) — odour named explicitly as a standards topic, numeric criteria not yet issued.

Mauritius replaced its 2002 Environment Protection Act with the Environment Act 2024 (in force August 2024), and the odour hook survived the rewrite: Part VI empowers the Minister to issue national environmental standards on a list of topics that still explicitly includes odour (s. 80), alongside water, air and noise. In practice, odour criteria can be set by ministerial standard rather than fresh legislation, and the Act’s enforcement-notice machinery (s. 110) is available where a breach appears likely — making Mauritius the one framework in this section that has already been modernised end-to-end.

Botswana

Regulatory mechanism: ambient/pollutant-specific — defines “noxious/offensive gases” generically, with no odour-unit metric.

Botswana’s Atmospheric Pollution (Prevention) Act (Chapter 65:03) defines “noxious or offensive gases” and “objectionable matter” in detail — an extensive list running from hydrocarbons and aldehydes to specific sources like tar works, cement works, glue factories and meat or fish processing — but the law is framed around named pollutant categories rather than a measurable odour standard.

Nigeria

Regulatory mechanism: hybrid — dedicated odour-nuisance clause plus specific ambient thresholds for hydrogen sulphide, ammonia and mercaptans.

Nigeria regulates odour under Part VII (‘Control of Odour’) of the National Environmental (Air Quality Control) Regulations (S.I. 64 of 2014, as amended in 2020), issued under the NESREA (Establishment) Act, 2007. Its nuisance threshold is unusually precisely worded: it may not result in annoyance to more than 5% of the local populace more than 5% of the time in any month, for up to three continuous months. It also sets air-quality limits for named malodorous substances — hydrogen sulphide at 5 ppmV, ammonia at 5 ppmV, and the notoriously low-threshold mercaptans at 0.0001 ppmV (the H₂S figure, notably, sits far above the gas’s odour threshold — the regulation’s own choice) — and separately defines ‘odour’ and ‘odour detectability’ in its interpretation section, which is more definitional precision than most countries in this survey manage.

South Africa

Regulatory mechanism: hybrid — a “reasonable person” nuisance test for odour specifically, plus national VOC/pollutant emission limits by industry.

South Africa handles odour, noise and dust together under the National Environmental Management: Air Quality Act, 2004, administered nationally by the Department of Forestry, Fisheries and the Environment (formerly Environmental Affairs), with real authority devolved to local government. The Act’s test is deliberately subjective — any smell “considered to be malodorous or a nuisance to a reasonable person” qualifies — and is paired with a national list of industrial activities and emission limits covering more than eight sectors, including specific references to VOCs and biofiltration-relevant compounds. Property occupiers carry an explicit legal duty to take reasonable steps to prevent offensive odours escaping their premises.

Europe

There is no odour law at the level of the European Union itself in the way there is, say, for water quality — but there doesn’t need to be, because most large industrial installations in the EU — those meeting the IED’s Annex I activity thresholds — already operate under a permit governed by the Industrial Emissions Directive (IED), and that permit can carry odour conditions.

The EU framework — and a 2024 update worth knowing about

Regulatory mechanism (EU-wide floor): ambient/BAT-based emissions framework — not odour-specific until the 2024 recast explicitly added “olfactory pollution” language.

Since 2010, the IED (Directive 2010/75/EU) has set the umbrella framework: large industrial installations across energy, waste management, mining, chemicals and intensive pig and poultry rearing may only operate with a permit, and that permit must reflect the “Best Available Techniques” (BAT) for the sector, as defined in reference documents called BREFs. The Waste Treatment BREF — whose revised BAT conclusions were published in August 2025 — remains the only instrument with an explicit odour limit, for certain biological-treatment processes; everything else is left to member states to fill in. A further test case is already underway: landfills were carved out of the 2025 waste-treatment revision so a dedicated Landfill BREF could be written — the first BREF to be drafted from scratch with IED 2.0’s ‘olfactory pollution’ language on the books.

The bigger shift came in 2024. The EU adopted a recast of the IED — Directive (EU) 2024/1785, informally “IED 2.0” — which entered into force on 4 August 2024, with member states required to transpose it into national law by 1 July 2026. It is the first time that ‘olfactory pollution’ has been explicitly mentioned in EU environmental law; it must be taken into account when defining Best Available Techniques (BAT) and when issuing or re-examining permits. It’s a modest textual change — odour appears in only a few places in a long directive — but it’s a meaningful one: for the first time, an EU-wide instrument gives national regulators an explicit legal hook to fold odour into BAT conclusions and permit conditions, rather than leaving it entirely to whichever member state or region happens to have built its own odour policy. Any published account of “EU odour regulation” that only cites the 2010 IED, without this 2024 update, is now out of date.

Why the UK’s permitting-led approach works without a national law

The UK case is a useful reminder that the absence of a national odour statute doesn’t necessarily mean the absence of effective regulation. Because most facilities with material odour potential need a permit or planning permission to operate, the H4 Horizontal Guidance framework achieves much of what a dedicated law would, simply by being baked into that existing permitting gateway. The trade-off is flexibility versus consistency: local authorities can set tighter standards where conditions warrant, producing better-tailored outcomes — but also meaning two similar facilities in different regions can face different odour requirements.

United Kingdom

Regulatory mechanism: dedicated, but non-statutory — Environment Agency guidance applied through the environmental permitting system (H4 Horizontal Guidance until Dec 2025; now ‘Odour management: comply with your environmental permit’).

Historically, UK odour assessments were benchmarked against the Environment Agency’s H4 Horizontal Guidance, which ranked activities by offensiveness (98th-percentile exposure benchmarks of 1.5, 3 or 6 ouE/m³, depending on offensiveness). The EA withdrew H4 in December 2025 and replaced it with ‘Odour management: comply with your environmental permit,’ which moves away from fixed numeric bands toward BAT- and ‘appropriate measures’-based judgment — worth flagging for anyone still citing H4 in a live permit application, and noting this is an Environment Agency (England) change: Natural Resources Wales has said it will keep using H4 until it publishes its own guidance.  

Germany

Regulatory mechanism: dedicated odour-specific standard (GIRL “odour hour”).

Germany’s system is arguably the most mature and heavily standardised in Europe. Its centrepiece, the Guideline on Odour in Ambient Air (GOAA/GIRL), spent two decades as a Länder guideline before being written directly into the federal Technical Instructions on Air Quality Control (TA Luft) as Annex 7 in December 2021 — making it binding nationwide under the Emission Control Act (BImSchG), supported by a dense library of VDI technical standards covering everything from biofilter design to how to run a neighbour-complaint survey. GIRL’s central idea is the “odour hour” — a threshold for how often, over a year, odour may be recognisable in a given area, with only limited weighting for certain agricultural odours. In residential areas, industrial odour may not be recognisable more than 876 hours a year (10% of the time); in commercial and industrial zones, the ceiling rises to 1,314 hours (15%). GIRL is used in day-to-day land-use planning, complaint investigations and facility licensing alike, with measurements carried out by accredited labs under the European standard EN 13725 and the newer EN 16841-1.

The rest of Europe: a mixed picture

Regulatory mechanism: Greece and Hungary — no dedicated standard, case-by-case under general IED/ambient permitting. Spain — ambient/BAT-based via IED transposition, no fixed national decision criteria.

Several European countries illustrate just how uneven implementation still is, even under a shared EU framework. Greece has no odour rules for industrial sources at all — odour gets a passing mention in national legislation on urban activities, but no binding limits — even though EU-standard measurement tools (EN 13725, EN 16841) are technically available, and any specific restrictions that do exist apply only on a case-by-case basis through IED permitting. Hungary similarly has no officially recognised National Odour Impact Criteria; the informally used benchmark (a 98th-percentile concentration of 3–5 odour units per m³) is a recommendation, not a binding rule. Spain applies general IED-based odour control (transposed via Law 5/2013 and Royal Decree 815/2013), with its autonomous regions handling implementation — and even Spain’s own guidance concedes there are no formal national decision-making criteria once an odour assessment comes back. But the regional layer has started to move: in December 2025 the Canary Islands became the first Spanish region to gazette numeric odour limits (Decree 185/2025), classifying odour-generating activities into three levels with ambient target values of 3, 6 and 9 ouE/m³ under EN 13725 — a Lombardy-style regional move that may not stay unique for long.

Netherlands

Regulatory mechanism: dedicated odour-specific standard (odour units + hedonic tone), set at provincial and municipal level rather than nationally.

The Netherlands has deliberately chosen not to set a single national odour number. Under the Environment and Planning Act (Omgevingswet), which replaced the old Activities Decree framework in January 2024, odour rules for most sources are set locally: provinces publish odour policies and municipalities embed thresholds in their environment plans, so local tailoring is now built into the legal architecture itself. National guidance (originally developed under the former environment ministry, VROM) still shapes these local policies heavily: as a rule of thumb, concentrations below 0.5 odour units per m³ at the 98th percentile are considered unlikely to cause nuisance, while readings above that — especially combined with an unpleasant “hedonic tone” score below −2 — typically indicate a real problem. In practice, thresholds are tailored by activity and context: new wastewater treatment plants near housing are held to roughly 0.5 odour units, existing plants to 1.5; livestock operations range from 2 to 14 units depending on whether the site sits inside or outside a designated agricultural concentration area; bakeries are allowed up to 5 units, slaughterhouses 1.5, and so on.

Italy

Regulatory mechanism: dedicated regional standard (Lombardy’s odour-unit and iso-concentration-map approach, since adopted elsewhere).

Italy has no binding national odour limits, but the national layer has thickened: Article 272-bis of the Environmental Code (2017) gives odour an explicit statutory hook, a 2023 ministerial decree (MASE Decree 309/2023) addresses industrial odour management and instrumental monitoring, and the SNPA agency network issued updated national monitoring guidelines in January 2025. However, the numerical tone was set by the Region of Lombardy in 2012, when it published the “General determinations regarding the characterisation of atmospheric emissions from activities with a high odour impact” (which built on a now-retired 2003 compost-facility guideline that had attempted a mandatory threshold of 300 ouE/m³). The 2012 approach requires any facility with an odour impact to model its own annual peak concentrations at the 98th percentile and draw impact maps showing 1, 3 and 5 ouE/m³ contour lines around the site. Trento and Piemonte adopted Lombardy-style rules early, and a growing list of regions — Puglia (a general regional odour law, L.R. 32/2018), Liguria, Basilicata and Friuli Venezia Giulia among them — now run their own frameworks.

France

Regulatory mechanism: dedicated, sector-specific odour standards (odour impact criteria in ouE/m³, set by decree per industry).

France doesn’t have one general national odour law either, but it has built some of the most specific, sector-by-sector odour rules anywhere in the world, on top of general IED coverage. Two examples stand out. For animal by-product processing plants (under an order dating to February 2003), the odour impact criterion is set at 5 ouE/m³ within a 3 km radius of the site fence, for no more than 175 hours a year (the 98th percentile) — checked either through on-site measurement or dispersion modelling, with quarterly olfactometric testing required if a plant’s stack concentration exceeds 100,000 ouE/m³ (continuous electronic sensors can reduce that to annual testing). Composting plants, under a separate 2008 order, work almost identically — same 5 ouE/m³, same 3 km radius, same 175-hour ceiling — but sites emitting under 20 million ouE per hour, or sited where odour impact is judged unlikely, are exempt from further action; sites that do exceed the standard must submit a formal Odour Management Plan. The food and beverage industry, meanwhile, is governed by a sliding scale of emission limits tied directly to stack height — the taller the stack, the higher the permitted emission rate, on the logic that height itself provides dilution before the odour reaches ground level.

Why the EU’s patchwork persists despite a shared directive

It’s worth dwelling on why Greece, Hungary and Spain look so different from Germany and the Netherlands, given that all five operate under the same overarching EU framework. The IED (both the 2010 original and the 2024 recast) deliberately sets only a floor — it requires permits to reflect Best Available Techniques, but it doesn’t mandate a specific odour number, leaving that entirely to national or regional discretion. Countries that already had strong domestic environmental-technical institutions before the IED existed — Germany’s VDI standards body, the Netherlands’ provincial environmental agencies — simply built odour-specific rules on top of the EU floor. Countries without that pre-existing institutional depth have tended to rely on the IED’s general permitting process alone, handling odour case-by-case rather than through a published national standard. IED 2.0’s new “olfactory pollution” language may narrow this gap over time, since it gives regulators in lagging member states a clearer legal basis to demand odour-specific BAT conditions as transposition beds in through 2026–27 — but it doesn’t by itself force any country to adopt a Germany-style numeric framework, so the gap described here is likely to persist for some years yet.

Germany and the Netherlands compared

Germany and the Netherlands both count as European success stories, but they arrived from opposite design philosophies. Germany chose national consistency: GIRL sets the same odour-hour framework nationwide, with technical detail supplied by a single, centrally maintained library of VDI standards, so a facility in Bavaria and one in Hamburg are assessed the same way. The Netherlands chose local flexibility: no fixed national number exists at all, and provinces and municipalities set their own thresholds calibrated to local land use and community expectations, with national guidance offering a shared toolkit rather than a hard limit. Both systems are mature and effective; the difference is really whether a country’s political culture favours uniform national standards or locally tailored ones — a genuinely useful choice-point for any government designing a system from scratch, including India’s.

What Africa and Europe show, side by side

The gap between these two regions is really a gap in regulatory age and enforcement capacity, not intent — most African frameworks reviewed here name odour explicitly as something worth regulating; they just haven’t yet built out the technical infrastructure (accredited labs, standard measurement protocols, enforceable numeric limits) that Germany or the Netherlands built up over decades. That’s a genuinely useful frame heading into the rest of this series: Part 3 turns to Asia and Oceania, where population density has pushed several countries toward strict source-level controls that neither Africa nor Europe generally uses; Part 4 pulls together a global comparison of how different measurement approaches actually perform in practice; and Part 5 asks what all of this means concretely for India — a country whose regulatory maturity on odour currently sits closer to Botswana’s or Nigeria’s than to Germany’s, despite an odour-complaint burden far larger than either.

If one idea from this post is worth carrying forward, it’s this: a shared legal framework doesn’t produce shared outcomes. Greece, Hungary, and Germany all sit under the same EU directive — what separates them is decades of institutional investment in measurement standards, accredited labs, and an enforcement culture. Keep that in mind as this series moves east.

Over to you

Are you working under any of the frameworks covered here — GIRL assessments in Germany, H4 guidance in the UK, provincial odour policies in the Netherlands, or the IED permitting process anywhere in the EU? We’d genuinely like to hear how these rules work (or don’t) in day-to-day practice, especially now that the July 2026 IED 2.0 transposition deadline has passed (and, as usual, many member states are running late) — drop a comment or get in touch. Subscribe to follow the rest of the series, and share this with colleagues in EU environmental compliance before their next permit review: the “olfactory pollution” language in IED 2.0 is going to show up in their permits sooner than most expect. Next up: Part 3 — Asia and Oceania, where three of the world’s densest economies decided that measuring odour at the receptor wasn’t enough.