Prevention of occupational risks in the logistics and port sectors.
In mainland France, there are 7 major seaports: Marseille-Fos, Le Havre, Dunkirk, Nantes Saint-Nazaire, Bordeaux, Rouen and La Rochelle. There are also 71 river ports, as well as 8 ports in the DROM-COM. Today, several hundred thousand people work in the logistics and port handling sectors. Each year, more than 5 million containers pass through French ports, half of which are shipped through Le Havre and a quarter through Marseille-Fos. The containers are then unloaded at one of the 5,000 warehouses and logistics platforms.
Source : INRS
The journey of a container
A container will travel a long way, sometimes between several continents. It may be in transit for a long distance until it arrives, and not be opened for several days or weeks.
The journey of a container will have several stages:
- loading on a transport ship
- the journey by sea
- arrival at the port
- opening of the container and its possible fumigation
- after opening the container, the loading of its goods on truck, train, etc.
The regulatory context
When a container is being fumigated, one might think that it is forbidden to transport it. Well actually no, according to the regulations issued by the IMO (International Maritime Organization), it is not completely forbidden. However, in this case, it is mandatory to warn the personnel in charge of the container and its transport. Indeed, this presents a certain number of dangers, and it is necessary to be prepared in case of incident.
The container must then be identified by the code UN3359, class 9 in the documents concerning it. In addition, a document must be in place, in which the conditions for handling the fumigation residues are indicated. The date of fumigation must be indicated, as well as the product used and whether or not the container was ventilated. In order to be visible to anyone who opens the container, this mark must be placed in every place with an opening.
Fumigation consists of using a toxic gas to destroy harmful organisms that may be present in the container. It takes place in 3 steps: gassing, exposure to the gas, and natural or mechanical ventilation of the container. The fumigants used are generally phosphine, carbon dioxyde, methyl bromide and le hydrogen cyanide.
Fumigants are generally toxic and the last ventilation step is not always effective or too short. The dockworker (or other people handling the containers) are exposed to serious irreversible disorders. Even at low doses, if exposure to the product is repeated, signs of eye, skin or respiratory irritation, nausea and vomiting, consciousness disorders, etc., may appear in the worker. This is why it is important to perform a detection measurement in the container.
The emission of gases and vapors
The container and the goods in it can emit other types of toxic gases and vapors such as CMR (Carcinogenic-Mutagenic-Reprotoxic). Depending on the type of manufacture and the components used, the gases and vapors emitted will not be the same.
> The dangers
For the docker, several risks are present. We will find :
The risk of falling: fall on the same level, because of slipping or tripping, or fall from a height, following the absence or failure of a guardrail)
Thermal risk: as the docker works mainly outside, he will be exposed to UV rays, bad weather, temperature variations, etc. This can lead to health problems, for example due to heat and prolonged exposure to the sun on the head (sunstroke, dehydration, etc.). The docker may be confronted with a risk of general malaise, muscle cramps, loss of consciousness, etc.
Chemical risk: after opening a container, the toxicity of the air can be very dangerous for the docker. Indeed, as previously mentioned, containers contain dangerous chemicals, such as fumigation products, gases and vapors. These fumigation gases, disinfectant (sanitation) or toxic (pest control) vapors are very harmful. They can cause problems for the docker: headaches, nausea, vomiting, dizziness, etc.
For all these reasons, it is very important that the docker respects collective and individual safety instructions.
In order to protect the workers as much as possible, it is necessary to determine the presence of toxic gases.
We will distinguish 3 categories of containers, defined according to several criteria (country of departure, supplier, fumigation or not, goods transported, gases present):
- A - Containers assumed to be "unpolluted
- B - "Uncertain" containers: the quality of the air inside is variable.
- C - "Polluted" containers: toxic gases are present.
For categories B and C, a gas detection process must be set up. The categorization must be updated at least once a year, when the single risk assessment document is updated.
In the case of a confirmation of the presence of a dangerous gas, it is imperative to set up a measurement system. There are several detection technologies. They are generally embedded in portable detectors. The most frequently encountered devices are photoionization detectors (PID), single or multi-gas detectors with electrochemical cells and/or infrared cells. The colorimetric tubes, on the other hand, allow an almost instantaneous detection once the sample is taken.
Many manufacturers have developed multi-gas detectors (up to six sensors): this solution allows, for example, to have, in theory, electrochemical sensors (PH₃, HCN, CO, H₂S, etc.) and PID in the same device.
It is strongly recommended to regularly check the operating condition of your detector. The best way to evaluate the condition of a detector is to expose it to a known gas at a known concentration. Then, a maintenance operation and a calibration may be necessary.
> Container ventilation
Natural ventilation: this is the simple act of opening a door or window. It is recommended to open for at least 30 minutes for ventilation to be effective. The efficiency varies according to the environmental conditions (wind, etc.). It is important to remain vigilant because when the door is opened, there is a risk of exposure to pollutants.
Mechanical ventilation: In mechanical ventilation, the container remains closed and is ventilated through the presence of a vent system. The speed of remediation is proportional to the ventilation rate.
Mechanical ventilation is generally recommended, although natural ventilation may be sufficient.
> Individual protection measures
During the activity, certain phases do not allow the implementation of collective protection, such as during the measurement of a pollutant concentration or the installation of a ventilation device. In these cases, the use of a respiratory protective device (RPA) is recommended. The table opposite gives you information on the type of cartridge to use depending on the gas present. This information varies according to the manufacturer. Respiratory protection against certain gases will require the use of a Self-Contained Breathing Apparatus (SCBA).
> Additional measures
In addition to protective measures, it is important to implement preventive measures. In order to ensure that personnel are vigilant when opening containers, they must be trained in manual and mechanical ventilation as well as in gas detection.