A French property listing rarely mentions that a classified industrial plant sits a few hundred meters away. To find out before a viewing, you need the home's exact address, then France's public risk data: the Géorisques portal, the local prevention plan and the risk statement the seller must give you.
Quick Answer: To check whether a French home is near a Seveso site, enter its exact address on Géorisques, review the classified installations and the local PPRT, then ask the seller for the risk statement at the first viewing. Distance alone does not measure risk: only the official zoning sets the rules that apply.
What is a Seveso site, and how is it different from an ICPE?
An ICPE (installation classée pour la protection de l'environnement, a "classified installation") is any industrial, farming or workshop operation that may create hazards or nuisances such as noise, smells or pollution. Depending on its risk level, it falls under a declaration, registration or authorization regime (French Ministry of Ecological Transition).
A Seveso site is an ICPE that stores, uses or produces dangerous substances above thresholds set by the EU Seveso Directive. France uses two tiers based on the quantities on site:
- Upper tier (seuil haut): the largest quantities and the strictest obligations. The ministry counts 702 in France (2025 figures).
- Lower tier (seuil bas): smaller quantities and proportionate obligations. The ministry counts 597.
That makes 1,299 Seveso establishments in total, according to the ministry's Seveso Directive page (updated 9 February 2026, checked in October 2026). Most classified installations are therefore not Seveso sites: a garage or warehouse can be classified for its nuisances without any major-accident hazard.
What is a PPRT and what do its zones mean?
A PPRT (plan de prévention des risques technologiques, a "technological risk prevention plan") is a state planning document, created by a law of 30 July 2003, that controls building around upper-tier Seveso sites. As of 30 June 2025, the ministry counted 386 PPRTs in force covering more than 800 municipalities. Lower-tier sites do not have a PPRT.
The PPRT boundary is drawn from the site's hazard study: thermal effects (fire), overpressure (explosion) and toxic effects (gas cloud). The most common zones are:
| PPRT zone | What it means for an existing home |
|---|---|
| Grey | The industrial site's own footprint. |
| Dark red | Very high exposure. The state can compulsorily purchase properties. |
| Light red | High exposure. The owner can ask to be bought out (droit de délaissement). |
| Dark and light blue | Lower exposure. Building is allowed under conditions; protective works may be required. |
Zones vary from plan to plan: always read the approved PPRT regulations and map, published on Géorisques or by the prefecture (the state's office in each French department).
How do you check an exact address on Géorisques?
Start by finding the property's candidate address. With FindAddressNow, you paste the listing link and get an address and coordinates to confirm: it is a research lead, not proof. Cross-check it against the photos, then follow these steps. Géorisques is in French; a browser translation works well enough for these pages.
1. Open the "Connaître les risques près de chez moi" report
On georisques.gouv.fr, enter the exact address (or the cadastral parcel, the land registry plot) and click "Accéder à mes risques". The report lists the natural and technological risks known at that address and in the municipality.
2. Review the classified installations
The Géorisques Installations classées database lists sites under authorization or registration, operating or closed, plus some inspected sites. Search by municipality and open the nearby records: they show the installation's regime and, where relevant, its Seveso status.
3. Read the PPRT, if there is one
If the report mentions a PPRT, place the building itself, not just the street, on its zoning map. If a boundary is unclear, ask the town hall (mairie) or the prefecture.
4. Ask the town hall for its information documents
Géorisques advises residents of a major industrial risk area to ask the town hall for its leaflets on alerts and what to do, and for the DICRIM (the municipal information document on major risks) if one exists.
What must the seller give you, and when?
The état des risques (risk statement, often still called ERP from its former name "état des risques et pollutions") is the regulatory document that says whether the property lies within a prevention plan: a PPRT, or a natural or mining risk plan, whether approved or prescribed. It also covers seismic zones, level 3 radon and coastal erosion. The rules below come from Service-public.fr (the French government's official information site, page checked 28 September 2026) and article L125-5 of the Environment Code:
- In the listing: every advertisement must state that risk information for the property is available on Géorisques.
- At the first viewing: since 1 January 2023, the seller must hand the risk statement to a prospective buyer at the first viewing, if one takes place.
- At the preliminary contract and the deed: the statement, dated less than six months earlier, is attached. If it is handed over after the preliminary contract (promesse or compromis), the buyer's withdrawal period only starts the day after it is received.
- If it is missing: the buyer can ask a court to cancel the sale or reduce the price.
The seller can produce this document free of charge with the ERRIAL service on Géorisques. Keep one limit in mind: the risk statement describes regulated zones. It does not replace your own look at the list of nearby installations.
What other nearby hazards should you check?
Also check:
- Hazardous material pipelines: Géorisques counts about 51,000 km of buried pipelines carrying gas, oil products and chemicals (not local gas supply). Their easements target venues for more than 100 people and high-rise buildings, not a single-family house. The local urban plan (PLU), at the town hall or on the Géoportail de l'urbanisme, shows whether the municipality is affected (Géorisques page).
- Polluted land: the CASIAS map records former industrial or service activities (garages, filling stations, dry cleaners) without assuming actual pollution. A SIS (secteur d'information sur les sols, a "soil information area") is land where known pollution requires a soil study before any building project (Géorisques dossier).
- Natural hazards: for flooding, see our article on flood risk and the PPRi. For radon and clay soils, see the radon and ground risk page (in French).
- Noise and smells: see our guide to checking the surroundings and nuisances of an address.
For land in a SIS, article L125-7 of the Environment Code requires the seller to inform the buyer in writing. If pollution later makes the land unfit for its use, the buyer has two years from the discovery to take action.
What does distance to the site tell you, and what does it not?
Distance alone does not settle anything:
- Far away does not mean out of reach. According to Géorisques, an industrial accident can expose people to thermal, toxic or overpressure effects up to several tens of kilometers away.
- Close by does not mean inside a regulated zone. A PPRT boundary follows the site's modeled hazards, not a circle around the fence. One nearby home can be outside the zone while another, further away, is inside it.
- The type of site matters more than the meters. An upper-tier Seveso site with a PPRT, a lower-tier site and a simple declared installation are not regulated at the same level.
There is no single "safe distance": the reliable reference is the property's official zoning.
How should you decide based on what you find?
| What the check shows | What it implies | Next step |
|---|---|---|
| No classified site or PPRT in the municipality | No industrial planning constraint | Still check pipelines and soils |
| Nearby ICPE, not Seveso | Mainly a nuisance question | Compare noise and smells at different times |
| Nearby lower-tier Seveso site | No PPRT, information to obtain | Ask the town hall for its leaflets |
| Property in a PPRT blue zone | Protective works may be required | Read the regulations, price the works |
| Property in a PPRT red zone | Buy-out or compulsory purchase possible | Get professional advice before any offer |
| Land in a SIS or on CASIAS | Use and works need care | Ask for any existing soil studies |
What are the effects on works, insurance, mortgages and resale?
The only effect quantified by an official source concerns protective works required for existing homes inside a PPRT. According to the ministry, about 15,500 homes are affected. The obligation is capped at the lower of 20,000 euros or 10% of the property's market value. A 40% tax credit is combined with 25% funding from the operator and 25% from local authorities, covering 90% of the cost (checked in October 2026).
For resale, the buy-out right in light red zones lets the owner ask to be bought out. We found no official source quantifying the effect of a PPRT on insurance premiums, mortgage approval or sale prices. Ask your insurer and your bank, risk statement in hand.
Frequently asked questions
How can I tell if my home is near a Seveso site?
Enter the exact address on Géorisques in the "Connaître les risques près de chez moi" section. Then review the municipality's classified installations to spot Seveso sites, and check whether the building sits inside a PPRT zone.
Does the risk statement list every nearby industrial site?
No. It mainly states whether the property lies within a prevention plan, including a PPRT, and other regulated zones. To see nearby installations that do not create zoning, check Géorisques yourself.
Does a CASIAS listing mean the soil is polluted?
No. The CASIAS map keeps a record of former activities that could have caused pollution. It does not assume actual pollution. Ask the seller for any existing soil studies if the land or its surroundings appear on this map.
Can I look around the neighborhood myself?
Yes, public streets are open to everyone. Arrange any viewing of the property through the listing's official contact, and do not approach occupants or neighbors.
Key takeaways
Find the property's exact address, check it on Géorisques, then ask the agent or seller for the risk statement before or at the first viewing. For questions about a zone or a boundary, contact the town hall or the prefecture. To organize the rest of your checks, follow our pre-offer verification method.
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