The risk of explosion is present in many sectors where hazardous substances are handled on a daily basis. These include flammable liquids such as paints or solvents as well as their vapours - but also flammable dusts. Whether processing, transporting or storing, the right measures must be taken to protect employees and equipment.
Below you will find out what you need to know about the risks of explosion and how to protect your facilities and employees against them.
What are the common errors made when it comes to protecting against explosions in the workplace? Which guidelines and operator obligations must be taken into account? And what do you have to pay attention to when classifying the ex-zones? Bastian Bröhenhorst is a DENIOS expert on explosion protection and answers these questions.
Mr. Bröhenhorst, where are the uncertainties with respect to explosion protection?
The moment an explosion occurs, the potential consequences are devastating and can lead to death. This is frightening for a lot of people which often means they do not address the topic properly and try to pass the responsibility onto someone else. This can therefore me be very dangerous but there are enough guidelines, guides and experts to guide people through this problem and ensure the right measures are put in place.
How is an explosion created?
An explosion occurs when there are three components present: oxygen, a flammable substance and an ignition source. If a spark occurs and hits a mixture of oxygen and combustible material (gases or dusts), it will explode. The prerequisite for an explosion is a suitable concentration of the substance. If too much oxygen is present and very little of the flammable substance, it will not explode because the concentration of the flammable substance is much too low. Alternatively, when the air is completely saturated with the combustible matter and no oxygen is present, there is no explosion. This is described with lower and upper explosion limits. The mixing ratio can therefore be used to prevent an explosion.
Which directives must be taken into account for explosion protection?
Both of the European community explosion protection directives (ATEX equipment directive 94/9/EC and ATEX workplace directive 1999/92/EC) oblige all persons, from suppliers to company management, to use corresponding best practise methods and equipment to protect the workforce.
As a manufacturer of products for use in areas with an explosive atmosphere we are obliged to safely develop and market these products accordingly, and this is regulated by the ATEX equipment directive 2014/34/EU which came into force to harmonise national regulations within the EU. Caution is required as products with a potential source of ignition need to be marked and as a result, ATEX is deeply rooted in our processes, especially when developing new products. We use a number of tried and tested templates and checklists to ensure right from the start that our products are suitable for use in potentially explosive atmospheres.
For the customer, the operator is responsible for avoiding or limiting the formation of explosive atmospheres, avoiding effective sources of ignition and limiting the effects of any explosion to a safe level and this is regulated by the ATEX company directive 1999/92 / EC. It is their responsibility to perform a risk assessment and put the right protective measures in place to protect workers from explosions.
What measures can be taken for explosion protection?
There are three steps that should be followed. The first step is to try to prevent the formation of an explosive atmosphere by controlling the ratio between oxygen and fuel. But this first step is the hardest and cannot always be guaranteed as most companies store hazardous materials because they need them. This automatically creates an explosive atmosphere. You can however still ensure that the mixing ratio is changed by installing technical ventilation systems in your room system.
The next step would be to prevent the ignition source becoming effective. If this cannot be achieved, the third step would be to control or limit the explosion to an safe level. An example here would be to install a pressure relief hatch. These pressure relief hatches are mounted on the roofs of room systems, where usually no one can be harmed.
What do you have to consider when purchasing products for hazardous areas?
Labelling is very important. Firstly, there are three ex-zones: Zone 0, Zone 1 and Zone 2 and some products are designed for use in different zones. In addition, users sometimes think that products may only be used in potentially explosive areas if they have a label and that is not always the case. Only products that fall under the ATEX Directive are subject to labelling and this is. among other things, when the products have a potential source of ignition. If the product does not have this ignition source, then it can bu used in an Ex zone and does not require labelling.
What do you need to know about classify ex zones?
The environment around the combustible substance is divided into three different zones, both spatially and in terms of time, taking into consideration any outgassing. Zone 0 is located directly in the hazardous area where there is a potentially explosive atmosphere, Zone 1 is located in the area around it and Zone 2 is located in the area around that. In addition, there is the temporal aspect to consider. To clarify, consider the example of a tanker with a petrol mixture on board. Inside the tank, above the surface of the liquid is the highest concentration explosive atmosphere. Here it’s Zone 0. When the tank is unloaded, the direct vicinity of the pumping nozzle, or hose connection, is Zone 1. In this zone, the likelihood of a dangerous explosive atmosphere being created is lower. As the distance from the pumping nozzle increases, the concentration of the substance and also the likelihood of an explosive atmosphere being created gets smaller, so this is classified as Zone 2. Depending on the zone, various safety precautions must be taken to prevent explosions.
We have it covered when it comes to explosion protection. Our huge range of products for use in potentially explosive areas covers all 3 levels of explosion protection. From extraction tables for removing hazardous fumes, to non-sparking products that avoid effective ignition sources. In addition, if your ATEX assessment does not prevent an explosive atmosphere or prevent the complete avoidance of sources of ignition, we will equip your hazardous goods warehouses with pressure relief flaps that limit explosions to a safe level.
Our expert team will be happy to advise you on the right solution for you.
EX Protection for your technical room system
Your operational, legal and insurance requirements will determine the safety measures required for the equipment of your technical room system. On the basis of your ATEX assessment and your individual risk assessment, we will work with you to determine the best explosion protection equipment package for your needs.
If your ATEX rating indicates an Ex zone, we can offer Ex products for installations that represent a potential source of sparks in the Ex zone. Grounding equipment is also available which allow electrical charges to be effectively and reliably dissipated away from an explosive atmosphere, therefore avoiding spark discharge.
For active safety in the event of an explosion, pressure relief hatches can be installed in the roof area to control the pressure. After the pressure wave has been removed, the pressure relief device becomes self-sufficient and seals the room system. Fire protection properties are retained. Request consultation now!
Detection of explosive emissions
DENIOS extraction tables effectively and safely remove explosive emissions that can arise during welding, soldering or gluing work. DENIOS extraction tables are available as ex-protected versions for Ex-zones 1 and 2. Here they offer the user maximum security. The installation of electrical equipment in accordance with Directive 94/9 / EC effectively reduces the risk potential.Request consultation now!!
Using commercially available steel tools can cause sparks - for example, by hitting or dropping the tool on the ground. Non-sparking tools for hazardous areas are made of special copper-based alloys and are softer than traditional tools, minimizing the risk of sparking. They are certified for use in areas where sparks cause a potential explosion hazard. Important to know: The use of non-sparking tools must not be the only protective measure in fire or explosion-prone areas. Please observe the regulations of your professional association.
Pumping and mixing in hazardous areas
To pump or mix flammable liquids, electric pumps and agitators must meet the requirements of the ATEX Directive. The motors are designed so that the devices can be safely operated. To dissipate static electricity, our electric pumps for hazardous areas are already supplied including equipotential bonding cables. Our hand pumps for hazardous areas are DEKRA approved and can be grounded with separately available grounding cables or anti-static kits.
Avoidance of ignition sources when lifting and transporting
Not only with the use of electrical equipment can ignition sources arise. When moving drums with mechanical tools, sparks can be created. Static electricity must also be excluded in hazardous areas as an ignition source. Products such as Secu Ex drum lifter are therefore completely dissipative, so that they do not have to be earthed by a directly connected equipotential bonding.
When filling or mixing flammable substances, the risk of static charge increases with the flow or bulk rate of the medium. This is true when filling by pouring into a funnel. With the help of earthing cables, users avoid the danger of explosion due to electrostatic charging
Floor marking hazardous areas shows employees which areas of the workplace are at risk of explosion. We offer a comprehensive range of labels.
Steel Spill Pallets
Products that do not have a potential source of ignition that can become an effective source of ignition are not covered by the ATEX Directive and can therefore be safely used in potentially explosive atmospheres even without labelling. This includes our steel spill pallets. They are therefore ideal for the safe storage of flammable liquids in drums or IBCs. Electrostatic charges can be prevented by effective grounding. For the storage of flammable liquids in small containers, we also offer a large selection of small containers made of steel.
Further products for use in hazardous areas:
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