The Italian National Environmental Protection Agency Network (SNPA) has published updated guidelines titled "Emissioni Odorigene: Elementi di Riferimento e Approcci Metodologici per il Monitoraggio" (Odour Emissions: Reference Elements and Methodological Approaches for Monitoring). This technical document, approved in January 2025, replaces the 2018 framework and introduces cutting-edge solutions to address one of Italy's most persistent environmental challenges: odour pollution.
Developed by specialists from 20+ regional environmental agencies (ARPA) and ISPRA, the guidelines reflect Italy's most comprehensive odour management strategy to date. Because this guideline is written mainly by regulators, it has an extensive chapter on the diferent regulations related to odour management nationwide and also at a regional and a local scale. There you will see Italy's fragmented regulatory landscape, with regions adopting different approaches to odour management ranging from composting regulations (Lombardy) to integrated prevention measures (Basilicata). The SNPA 2025 guidelines aim to harmonize these framework.
There is an interesting table with regional odour emission regulations.
| Region/Province | Sector-Specific Regulations | General Regulations |
|---|---|---|
| Piedmont | - | Regional Law (L.R.) 43/2000 Regional Government Resolution (D.G.R.) n.13-4554 (09/01/2017) Guidelines for the characterisation and containment of atmospheric emissions from odour-generating activities |
| Lombardy | Regional Government Resolution (D.G.R.) n.12764 (16/04/2003) Guidelines for the construction and operation of compost production plants |
Regional Government Resolution (D.G.R.) n.IX/3018 (15/02/2012) General determinations regarding the characterisation of gaseous atmospheric emissions from activities with significant odour impact |
| Autonomous Province of Trento | - | Deliberation n.1087 (24/06/2016) Odour Guidelines |
| Veneto | Regional Government Resolution (D.G.R.) n.568 (25/02/2005) Technical standards and operational guidelines for the construction and operation of organic waste recovery and treatment plants by means of composting, biostabilisation and anaerobic digestion |
Environmental Impact Assessment (VIA) Committee (08/11/2023) The MASE 2023 Decree is to be used as operational guidance for the assessment of odour impact in Environmental Impact Assessment procedures |
| Friuli Venezia Giulia | - | Regional Law (L.R.) 13/2022 and L.R. 3/2024 (Art. 88) Amendment to Article 4 of L.R. 13/2022: Regional guidelines for the prevention and limitation of odour emissions from industrial plants under Legislative Decree 152/2006, to be defined within 180 days of the entry into force of L.R. 3/2024 (by May 2024) |
| Liguria | - | Regional Government Resolution (D.G.R.) n.810 (05/08/2020) Guidelines for the definition of Odour Management Plans |
| Abruzzo | Regional Government Resolution (D.G.R.) n.400 (26/05/2004) Performance and management requirements for urban waste treatment plants |
- |
| Puglia | - | Regional Law (L.R.) 32/2018 Regulations on odour emissions Regional Government Resolution (D.G.R.) 805/2019 Operational protocol for the management of olfactory disturbance reports |
| Basilicata | - | Regional Government Resolution (D.G.R.) n.466 (11/06/2021) Guidelines for the prevention, mitigation and characterisation of odour emissions from plants subject to Integrated Environmental Authorisation (Legislative Decree 152/2006) L.R. 39/2021 Rules for the prevention and limitation of odour emissions |
| Sicily | Commissioner’s Ordinance 29/05/2002 Guidelines for the design, construction and management of composting plants |
Administrative Decree (D.A.) 16/12/2015 (Art. 5) Directives on the content of authorisations issued pursuant to Part V of Legislative Decree 152/2006 |
| Emilia-Romagna | Regional Government Resolution (D.G.R.) 1495 (24/10/2011) Technical criteria for mitigating environmental impacts in the design and management of biogas plants Regional Government Resolution (D.G.R.) 2347 (22/11/2019) Technical criteria for mitigating environmental and territorial impacts for new plants recovering organic fraction of municipal solid waste (FORSU) for biogas and biomethane production |
Determination 426/2018 Approval of internal circular containing Operational Guideline 35/DT “Operational guidance on the application of Article 272-bis of Legislative Decree 152/2006” |
| Sardinia | - | Regional Government Resolution (D.G.R.) n.9/42 (23/02/2012) Regional directives on atmospheric emission authorisations |
| Tuscany | - | Regional Law (L.R.) n.25 (03/07/2024) 2024 Regional Maintenance Law |
For detailed implementation, please consult the relevant regional environmental protection agencies (ARPAs).
The document begins with foundational concepts, detailing physiological odour perception mechanisms (Section 1.1) and the characteristic properties of odours, such as intensity, hedonic tone, and detectability thresholds (Section 1.2). It then outlines Italy’s national and regional regulatory landscape (Section 2), emphasizing the fragmented regional frameworks (e.g., Lombardy’s D.G.R. IX/3018 for odour-intensive activities and Veneto’s adoption of the MASE 2023 Decree) alongside national provisions like Article 272-bis of Legislative Decree 152/2006, which mandates harmonized odour impact assessments. The guidelines stress the need for standardized monitoring practices, including dynamic olfactometry (Section 3.3), chemical characterization via GC/MS and GC/O (Section 3.2), and instrumental odour monitoring systems (IOMS) (Section 3.4).
The technical standard UNI 11761:2023 represents a reference point for the use of IOMSs in Italy, providing guidelines on their design, installation, and operation. This standard establishes three measurement types:
- Presence/absence measurement (Type A) - Detects the presence or absence of odour without further detail.
- Odour class measurement (Type B) - Classifies odours into predefined categories, enabling qualitative assessment of odour types.
- Odour quantity measurement (Type C) - Quantifies odour on a scale correlated with odour concentration, determined according to EN 13725.
Within the national regulatory framework, the Ministerial Decree No. 309 of 28/06/2023 issued by the Ministry of Environment and Energy Security (MASE 2023) served as a key reference. Annex A.5 specifically addresses Instrumental Odour Monitoring Systems (IOMS) in the context of managing and controlling olfactory impacts from industrial activities.
The document also addresses modelling and mitigation strategies. Section 4 focuses on dispersion modelling for odour impact assessments, outlining criteria for atmospheric simulations and their role in authorization processes. Section 5 proposes integrated evaluation tools for odour nuisance, combining quantitative data (e.g., ouE/m³ thresholds) with qualitative assessments, such as community perception surveys and web-based reporting systems (Section 3.5). Finally, Section 6 details abatement technologies, including biofiltration, chemical scrubbing, and catalytic oxidation, with sector-specific applications for wastewater plants, refineries, and waste treatment facilities.
This guideline is available to everyone for free here: https://www.snpambiente.it/snpa/emissioni-odorigene-elementi-di-riferimento-e-approcci-metodologici-per-il-monitoraggio/
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- The Italian pilot for the HORIZON 2020 D-NOSES Project: combining citizen science and dispersion modelling to identify odour sources in the municipal area of Castellanza
