Today we are talking about major infrastructure works in relation to the portable chemical toilet sector. The first thing to consider is that, in this case, the logistics of sanitary facilities becomes a technical chapter in its own right. Placing a chemical toilet on an urban building site is one thing; guaranteeing it along dozens of kilometres of motorway, in the heart of a tunnel or alongside a railway line in service is quite another.

As the spaces change, so do the risks, and above all so do the rules to be followed. In this article we will discover what these sites have in common, and what instead makes them profoundly different.

The regulations on portable chemical toilets that apply to every site

Before getting into the specifics, let’s start with the basics. When it comes to chemical toilets on construction sites, the regulatory references are:

• The Legislative Decree 81/2008 (D.Lgs. 81/2008) 81/2008, in particular Annex XIII, referred to in Article 96. Here we find the minimum figures: washbasins must be provided in a minimum ratio of one for every 5 workers and one toilet for every 10 workers employed on the site. The same rule specifies that, when portable chemical toilets are used for particular needs, they must have characteristics such as to minimise the health risk for users. Moreover, in the event of a breach of the measures set out in the Annex, Article 159 even provides for imprisonment from 3 to 6 months, or a fine from 3,000 to 12,000 euros.
• UNI EN 16194:2023, which applies to mobile toilets not connected to the sewage network and specifies the requirements for installation services, sanitary products, cleaning and the number of cabins, taking into account hygiene, health and safety. The same standard classifies the fields of use and keeps distinct, for example, construction sites (type D) from industrial construction such as ports, refineries and power plants (type F). For construction sites the operating criterion is clear: one mobile toilet for every 10 users, with an indicative maximum distance of 100 metres from the workplace and, on multi-level sites, at least one toilet every two floors.

But how does this regulatory baseline apply to major works, and what are the differences?

Chemical toilets for motorways and major roads: what does the standard require?

On motorways and major arteries, the site is of the road type. Its distinguishing feature, which sets it apart from a traditional site, is that it is long and it moves. Crews work on positions kilometres apart, often for just a few days at each point, and returning to the base camp every time is not practical.

The legislator anticipated this. The use of caravans or trailers as sanitary and welfare facilities is permitted on road sites of significant length and with short working times on individual positions that are very far apart, in addition to the ordinary sanitary and welfare facilities located at the site areas or base camps. In these cases, therefore, the mobile solution becomes an integral part of the logistics, and is not a secondary measure.

In practice, on a motorway site what matters most is:

• Distribution along the route, because the 100 metre limit from the workplace set out in UNI EN 16194 must be rethought over a linear development of kilometres.
• Speed of installation and relocation, given that the work fronts advance continuously.
• Total independence from the water and electricity networks, since connections along the carriageways simply do not exist.
• Safety with respect to vehicle traffic, with positioning in protected and signed areas.

Chemical toilets for tunnels and underground works: what changes?

In a tunnel it is not only the Consolidated Act that applies. A historic but still current decree comes into play, Presidential Decree no. 320 of 20 March 1956 (D.P.R. 20 marzo 1956 n. 320) 320which lays down the rules for accident prevention and occupational hygiene underground and applies to the construction, maintenance and repair of tunnels, caverns, shafts and similar works.

A useful threshold to remember: for tunnels no longer than 50 metres only certain chapters of the decree apply, whereas for more extensive works the full framework is in force.

Compared with an ordinary site, underground there are additional elements that must necessarily be taken into account, which change how the regulations are applied. One of these is the nature of the environment: the tunnel is often a confined space, with everything that this entails in terms of ventilation, access and emergency management. For this reason the positioning of the facilities should generally be studied at the entrance or in dedicated areas, away from the excavation face. What to keep in mind in a tunnel:

• A dedicated regulatory reference (DPR 320/1956), which is added to Legislative Decree 81/2008. 81/2008.
• A more “diluted” ratio of latrines compared with a building site, but with strict hygiene and construction constraints.
• The need for robust, ventilated solutions that can be managed in spaces where humidity and dust are the norm.

Chemical toilets on railway sites: safety on the tracks

On the railway front the dominant issue is coexistence with train traffic. The operational reference, in this case, is the Instruction for the Protection of Construction Sites (IPC) issued by RFI, a railway regulation that protects, through behavioural and organisational measures, the safety of operations and the wellbeing of the personnel working on mobile and temporary sites along the lines and in the stations. At European level the UNI EN 16704 series is added, which defines a common approach to the safety of workers with respect to railway risks for work on or near the tracks.

The detail that most affects the logistics of sanitary facilities is the safety distances. The regulation sets the occupation by men only up to precise distances from the nearest rail: 1.50 metres for speeds not exceeding 140 km/h, up to 2.15 metres for speeds not exceeding 250 km/h. There is then the construction constraint of DPR 753/1980, which along railway routes generally prohibits buildings and structures at a distance of less than 30 metres from the limit of the occupation zone of the nearest rail.

For site toilets this means no cabins inside the clear transit gauge or in the safety zones, positioning in the base camp and accessibility without crossing tracks in service. The priorities become:

• Placement in protected areas, outside the critical distances from the track.
• Quick and safe reachability for the crews, without interference with trains.
• Coordination with the working regimes (track interruption, protection of the adjacent track) provided for by the IPC.

The regulations compared, in summary

To sum up, then, here is how the main reference changes against a shared common baseline (Legislative Decree 81/2008 and UNI EN 16194:2023):

• Motorways and roads: Annex XIII point 6.2, mobile and distributed solutions along linear routes, attention to traffic.
• Tunnels: DPR 320/1956, latrines at least 1 for every 20 workers, specific construction requirements, management of the confined environment.
• Railways: IPC RFI and UNI EN 16704, safety distances from the track, positioning in the base camp.

How to choose the right chemical toilet solution

The common thread running through all these works is one: you need reliable units that are independent of connections, easy to move and robust enough to withstand difficult environments. For those managing toilets intended for sites of this kind, modularity makes the difference, both during transport to remote sites and in field maintenance, where being able to intervene without bringing the toilet back to base means saving time and downtime.

Tblustar, a leader in the portable chemical toilet sector, designs solutions conceived precisely for the most demanding professional contexts, from long-duration sites to logistically complex situations. If you are planning the sanitary facilities for a major work and want to understand which configuration is best suited to your site, contact the Tblustar team, always available for a dedicated consultation.