C-DRONE GUIDE · 25 AUGUST 2026
Drone and Industrial Flour Mill: ICPE Heading 2260, Dust Explosion Risk and Prices
A thirty-metre elevator tower squeezed between two neighbouring buildings, a roof covered in dust-extraction ducting and cyclones that nobody climbs willingly, and a risk the trade knows by heart without ever quite being able to show it : the fine layer of flour that settles everywhere and, in quantity and suspension, becomes an explosive. At an industrial flour mill, a rice mill or a semolina mill, most of what an operator needs to check — roof condition, explosion vent clearance, dust deposits at height, how the grain intake yard is used — is visible from the air and poorly checked from the ground or from a lift that cannot reach everywhere. Here is what the drone documents on this kind of site, what it does not replace, and the prices.
Published on 25 August 2026, reviewed on 26 August 2026 — regulations in force as of August 2026.
Flour mills, rice mills, semolina mills: ICPE heading 2260 and the dust explosion risk
An industrial flour mill grinding wheat, a rice mill hulling and polishing rice, a durum wheat or maize semolina mill, or an animal feed compound plant all fall in France under the same regulatory family : ICPE heading 2260, which covers grinding, crushing, screening, sifting, bolting, mixing, peeling and hulling of plant substances and any natural organic product. These activities are named explicitly. A quirk of the heading : the applicable regime — declaration, registration or authorisation — is set by the installed power of the fixed machines doing mechanical grain work, a criterion specific to this heading and quite different from the storage volume that governs the neighbouring silo heading, 2160. General requirements are set by three texts depending on the regime : the order of 23 May 2006 for declaration, the order of 22 October 2018 for registration, and the order of 18 February 2010 for accident-risk prevention under authorisation.
The risk shaping everything else comes down to one word : dust. Flour, semolina, bran, rice dust — suspended in air, in sufficient concentration and with an ignition source present, these organic particles become explosive, a phenomenon long known in the milling trade. A landmark review by T. Abbasi and S. A. Abbasi, published in 2007 in the Journal of Hazardous Materials, surveys dust explosions across the process industry and highlights a central mechanism of milling risk : an initial, often limited explosion lifts, with its blast wave, dust deposits accumulated on surrounding surfaces — roofs, beams, ducting —, creating a second cloud that ignites in turn and propagates the event in a cascade through the whole building (see the study on Google Scholar). It is precisely this secondary-explosion mechanism that means a visible dust deposit on a roof or a wall cladding is never treated as a cosmetic detail.
Elevator tower and roof: what the orthophoto and 3D model document
The most distinctive building on a flour mill site, the elevator tower or headhouse, concentrates every access difficulty : often twenty to forty metres tall, squeezed between neighbouring buildings or a manoeuvring yard, it suits neither scaffolding nor, in most cases, a lift that cannot reach the façade. A photogrammetric flight produces a 3D model and an orthophoto of the whole — roof, façades, dust-extraction ducting, cyclones, external pneumatic pipework — without stopping production. The reading is direct : a rust spot on a duct, a loose cladding sheet, a degraded roof seal, a blocked gutter likely to cause water ingress above a flour stock or an electrical panel. This service falls under our drone façade inspection and surveying and photogrammetry offers.
At the foot of the tower, the grain intake yard — trucks queuing to unload, temporary windrows during peak intake, bulk bags of bran or middlings — lends itself to the same counting and volume measurement as neighbouring cereal silos : our guide to thermal monitoring of grain silos details the method, directly transposable to a flour mill's yard during peak intake. Repeated on an identical flight plan from one campaign to the next, this coverage becomes a comparable series, useful for a registration renewal file, a stock count or an insurance declaration.
Relief vents and dust deposits: what an overflight checks
Explosion protection at a flour mill relies heavily on relief vents : panels or surfaces designed to give way on purpose, sized to vent an explosion's overpressure outward before it bursts the structure, fitted on silos, cyclones, bag filters and certain sections of the elevator tower. Their effectiveness depends on a condition that is simple to state and regularly compromised in practice : the discharge path must stay entirely clear. Yet a lean-to roof added later to shelter an electrical panel, a service walkway fitted without revisiting the original layout, equipment stored against an outside wall, or scrub growing under a ground-level vent can obstruct that path without anyone noticing from inside the building. A manual-flight pass, aimed specifically at each vent listed in the prevention plan, produces a dated image that shows whether the path is clear — or is not — far more reliably than a ground patrol that does not always see what happens on the roof or high up a façade.
The same pass documents visible dust deposits : flour or bran built up on a flat roof, a cornice, the top of a cladding panel or the outside of a dust-extraction duct — exactly the kind of deposit that makes the secondary-explosion mechanism described by Abbasi and Abbasi critical. None of these observations replaces the periodic cleaning schedule required by the explosion protection document, but a dated photographic report, flagging each point, helps prioritise action and document how it is tracked over time.
Thermal patrol: real value and limits at a flour mill
The thermal camera has a targeted but limited use on this kind of site. It effectively spots a surface hot spot : a conveyor bearing or an elevator boot running abnormally hot as seen from outside, a friction zone on a duct, a temperature difference revealing insulation failure on an external steam line where the site has one. It is, however, blind to what happens deep inside a mass of grain or bagged flour : a self-heating pocket starting deep inside an adjoining silo, a phenomenon covered in detail in our guide to thermal monitoring of grain silos, generally takes several days to show at the surface — when it does before reaching a critical stage. No serious operator would base fire detection on this periodic pass alone ; it complements fixed sensors, silo probes and human patrols, and never replaces them.
The flight protocol itself draws on a method already proven for this kind of building. A study by Javier Gómez and Alberto Tascón, published in 2021 in the journal Informes de la Construcción, developed and validated a drone inspection protocol for a tall agro-industrial building, structured into successive flight plans tailored to each façade and to the roof (see the study on Google Scholar). It is this logic of dedicated flight plans — one per tower façade, one for the roof, one for the yard — that structures an effective mission at a flour mill.
Method, ATEX flight framework and prices
The mission runs half a day to a full day depending on the tower's height and the number of buildings. It starts with a briefing with the QHSE or maintenance manager : the list of relief vents to check, ATEX-classified areas to avoid flying low over or during an active production phase, truck traffic in the intake yard, a take-off point set well clear. The flight then runs a photogrammetric pass over the tower and adjoining buildings for the orthophoto and 3D model, close manual-flight shots of each vent and each notable roof point, a thermal pass if included, and a survey of the intake yard if a volume count is requested. As with any mission on an industrial site, the prevention plan and coactivity with staff are settled before the flight, not on the day itself.
Two precautions frame the mission. On the airspace side, a flour mill often sits in a business park or a historic town centre — many flour towers date from the 19th century and have stayed at the heart of the village — which requires checking the zone on Géoportail before any quote and can call for particular organisation under the open category, as detailed in our guide to flying a drone in French cities. On the insurance side, up-to-date professional liability insurance is a non-negotiable prerequisite for a contractor working on this kind of sensitive site.
2026 prices (excl. VAT) : €500 to €1,000 for an orthophoto and photographic report campaign on a typical flour mill (tower and adjoining buildings) ; €1,200 to €2,200 for a full campaign combining orthophoto, relief-vent clearance checks, a thermal pass and intake-yard volume measurement ; €300 to €600 per visit for recurring monitoring on the same flight plan ; €350 to €700 for a standalone thermal patrol. A travel charge applies beyond a 30 to 50 km radius. Request a quote stating the elevator tower's height, the number of vents to check and the goal (regulatory file, stock count or fire prevention).
Frequently asked questions
Can drone imagery replace the explosion protection document (DRPCE)?
No. The DRPCE is a statutory risk assessment — ATEX zoning, ignition sources, organisational measures — drawn up by the operator and its engineering consultant, who remain responsible for it. The drone analyses nothing : it produces a dated picture of the site's outward condition — roof, cladding, vents, visible deposits — which can feed into updating the document or prepare an environmental inspectorate visit, but never substitutes for it.
Can a drone fly near explosion relief vents safely?
The flight is a remote observation : the drone never hovers directly above a vent or generates a shock on a relief panel ; the aim is to visually check that nothing obstructs the discharge path (an added lean-to roof, vegetation, stored equipment), not to work on the equipment itself. The briefing with the site's QHSE manager sets the distances and the areas where the aircraft stays on wide observation, particularly above equipment in operation.
Does a thermal patrol detect early self-heating inside an adjoining wheat silo?
It reads a surface temperature : cladding, roof, external pipework. A self-heating pocket starting deep inside a grain mass, several metres from the wall, often takes days to show at the surface, and may never do so before reaching a critical stage. As detailed in our guide to thermal monitoring of grain silos, a drone patrol complements the silo's fixed temperature probes ; it never replaces them.