Propagating brush discharge has sufficient energy to ignite fuel-air mixtures of any kind. Since several conditions are required for the occurrence of this discharge type, its probability of occurrence is relatively low. If in doubt, consult an expert. Since propagating brush discharge only occurs in insulation material surfaces, use of conductive or electrostatic conductive transport or conveying systems is also adequate protective action in this case.
Electrostatics and its ignition risks is a very complex issue. Requirements are well regulated for parts and components in so-called Ex-ranges, i. In sections with high levels of air change and lower solvent volumes, which are not defined as ex-zones, it must also be ensured there is no electrostatic ignition source in the area of emissions or in the area where solvents are handled in the open.
Any electrostatic discharge occurring in such an area would automatically cause an ignition of the mixture and, in the worst case, cause the canister to explode. Such an emission should be avoided, for example, by using appropriate filter systems. If this is no possible, it must be ensured that at the place of solvent emission or the area of open handling of such substances for example, waste solvent collection places no electrostatic risk can develop.
This TRBS describes risks and specifies protective action. Therefore, the contents of the Technical Rules TRBS are useful here as an source of information and can be referred to if you have any questions.
How ignition hazards can be avoided due to electrostatic charge in the lab? Here you will find support and recommendations for your safety more. It features useful information about markets, trends and innovations. Our advertising formats support you in getting your message across to a clearly defined target audience. Deutsch English. Explanations of different possibilities of electrostatic charging and avoiding ignition risks Kurt Moritz.
Share on. Request information now. More about SCAT. Most read white papers. Topics A-Z. All topics. Electric charges can build up on an object or liquid when certain liquids e. This charge can occur when liquids are poured, pumped, filtered, agitated, stirred or flow through pipes.
This buildup of electrical charge is called static electricity. Even when liquids are transported or handled in non-conductive containers, something rubbing the outside surface of the container may cause a static charge to build up in the liquid.
The amount of charge that develops depends, in part, on how much liquid is involved and how fast is it flowing or is being agitated or stirred. Depending on circumstances, static electricity can be a nuisance or a hazard.
Static cling in your clothes can be a nuisance but a spark that has enough energy to cause a fire or explosion is a definite hazard. To decide if static electricity is likely to be a hazard, you must consider several factors:. Be aware that when a person walks around, there is a redistribution of the static electric charge on their body as they get close to or leave an area where there is a charge. This change is also related to any items the person may have on their body, such as clothing, tools, flashlights, pens, etc.
Flammable and combustible liquids can present a static electricity hazard depending on their ability to generate static electricity, how well they conduct electricity conductivity , and their flash point.
Solvents and fuels produced from petroleum e. They tend to hold a charge because they cannot conduct electricity well enough to discharge when in contact with a conducting material, like a metal pipe or container, that is grounded. When enough of a charge is built up, a spark may result. If the vapour concentration of the liquid in air is in the "flammable range" and the spark has enough energy, a fire or explosion can result. Examples of such liquids include alcohols and ketones like acetone.
However, when liquids are transferred into non-conductive containers e. The flash point and vapour pressure of the liquid and the temperature are other factors to consider. People also generate static as they go about their work moving equipment, materials or simply walking about; remember the elevator button or shock from your car?
Powered machinery and equipment can also generate charge on the equipment or processed materials. There are things going on here that are common to all.
In most cases there is movement with c ontact and separation of surfaces. Powder movement, liquid flow, machinery with moving part and people are ALL subjected to surface contact and separation in some form. But charge generation is not enough to create the effects described in our table. We do need that generated charge to build up accumulate on something if we are to see an effect. Charge can build up on people and plant — fixed or mobile, conducting or insulating.
It can also build up on the process materials — usually low conductivity liquids or insulating powders. In fact, charge can accumulate pretty much wherever there is no direct conducting path to ground along which the charge may flow.
Sparks: Static builds up on conductors that are not grounded. Sparks of these types will typically jump a few millimeters. They can be seen from metal drums during filling or emptying, from isolated metal plant such as pipes or conveyors and they are normally discrete events one at a time.
Sparks can also be experienced by operators that have become charged. In all these cases, the sparks are energetic enough to ignite gases, vapors, and dust clouds, and if detected must be investigated immediately.
This can cause a huge spark to form between the ground and the cloud. This causes lightning — a flow of charge through the atmosphere. Here are some examples of dangers associated with static electricity:.
Refuelling aircrafts and tankers also poses a particular danger.
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