Most common problems and defects of fume and dust extraction systems

Top 5 defects of fume or dust extraction systems, more commonly known as Local Exhaust Ventilation (LEV).

Effective LEV can carry away airborne contaminants before they can be breathed in. The LEV system removes air from the area of work, whether that is a school laboratory, or a factory. It then filters the air to remove contaminants before expelling the air outside or recirculating it back into the working environment.

The air quality in these areas can be contaminated by a range of airborne contaminants that are hazardous when breathed in. Airborne contaminants may occur as vapours, dust particles, fibres, fumes or gases or combinations of these. Breathing in high levels of contaminants or low levels over a long period of time can overwhelm the human body’s defence system resulting in disease. Exposure to certain airborne contaminants has the potential to cause or worsen a wide range of serious respiratory diseases including:

  • Asthma
  • Cancers of the respiratory system
  • Chronic obstructive pulmonary disease
  • Mesothelioma
  • Silicosis

Thurra’s engineers will conduct a thorough examination and test the LEV system against the commissioning report (or equivalent). At their disposal they have a comprehensive range of examination and test methods which they can use to establish the efficiency of the equipment.

All workplaces have the responsibility to ensure that the LEV systems installed are working efficiently and are keeping employees and visitors safe. Whether it is chemical fumes in laboratories or dust fumes in workshops, they all present a potential risk to personnel.

Here are the 5 most common problems we encounter when inspecting LEV:

  1. Blocked filter. Blockages in the LEV filtration system can occur because of many different reasons. The main reason generally happens as a result of poor maintenance. In such circumstances the effective extraction capability becomes less and less. Thereby not removing the required contaminated air from the area where people are working. At every scheduled inspection, Thurra’s engineer will measure the efficiency of the filter and visually inspect the filters condition. On completion, Thurra’s engineer will discuss their findings, whilst bringing any areas of concern to attention.
  1. Obstruction in the extraction ducting. Wood working workshops are notorious for collecting heavier particles at certain parts of the system. At such points in the extraction ducting the efficiency of the system will be reduced and thereby have the knock-on effect of not extracting all the dust particles that it was designed to do. In this condition the system would not remove the contaminated air from the designated place of work. Thurra’s engineer will study the results of their examination and using a logical approach identify the location of the blockage / restricted flow and inform the owner of the extraction system where the blockage is. All conversations with the system owner are supported by a report of examination which would identify any areas of concern.
  1. Extraction hood incorrectly positioned. The positioning of the extraction hood can have a very significant effect on the operation of the LEV system. If the system is not correctly positioned, the system could be extracting air from the work area less efficiently than necessary, leaving contaminants to continue to circulate around personnel and inhaled without knowledge. The physical positioning of extraction hoods is assessed at every visit with all concerns brought to the attention of the on-site representative.
  1. Holed / damaged extraction hood. All extraction systems are designed to remove contaminated air from the area of work. If the system is damaged and has holes in the trunking, the efficiency of the system will be reduced. The physical integrity of the system is assessed at every examination with damaged areas including holes reported to the customer. Such holes reduce the efficiency of the system and increase the risk to those working in the environment.
  1. System not appropriate for the removal of all contaminants. Having the appropriate system in place to remove contaminants from the workplace is an essential requirement. In the majority of cases, the original systems fitted are appropriate. However, over time additional extraction points are quite often added and in doing so the capability of the system is compromised. At every thorough examination a ‘fit for purpose’ assessment is conducted and the results are communicated to the customer. Additional extraction points in a LEV system reduce the efficiency to remove contaminants and increase the risk to the personnel in the vicinity.

Thurra’s team of experienced engineers will assess the condition of LEV systems advising on the condition of the equipment and whether or not any remedial action is required to ensure that they continue to operate safely and effectively. A formal written report will be sent which should be kept as confirmation of the equipment’s status and if required it should be presented to your maintenance contractor.

If you require advice or help on any of the above, please speak to your Insurance Broker or get in touch with us for advice or to arrange a visit by an experienced engineer.

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