Dangers of Paper Dust
Paper dust is another one of those dusts that the dangers can be more from the combustibility and explosive risk than just breathing the dust in. As we have discussed before in this blog, many times in fact, breathing in foreign bodies, like any type of dust, can pose health risks over time. Repeated exposure at some where like a work place, where you may breathe in the dust day after day, can lead to a gradual build up of these dusts in your respiratory system and could potentially cause long term health effects.
Paper Dust Combusts
We all now how well paper burns. Paper contains carbon, hydrogen and oxygen. Like many flammable materials paper can struggle to burn in large lumps, but spread it out, increase its surface area and increase the surfaces exposed to the air and then it becomes highly combustible.
Dust clouds are small particles of dust suspended in air. Each particle has a large surface area relative to its size. When the cloud reaches and optimal mix of air and dust it can become highly combustible and potentially explosive. Small dust particles will burn very quickly and release energy very quickly once ignited. If there is enough, then the conflagration pulls in more air, increasing the rate of reaction. The energy release is so fast it results in an explosion.
The explosion can shake loose settled and solidified dust layers or cakes, adding to the fuel mix and burning or smouldering embers can be thrown out by the explosion, landing in other areas and creating secondary fires or explosions.
Paper dust as an explosion risk tends to be found in certain industries, paper mills Tissue Mills, large scale printing presses like newspaper presses. Paper mills tend to be primary danger areas and the Health and Safety Executive (HSE) has documentation and guidelines on general fire control in Paper Mills which can be downloaded for free from their website.
There is a link at the bottom of the article.
Wider controls and considerations are always needed when it comes to protecting against the risk of fire and explosions. Good housekeeping, proper risk assessment and management and effective controls on plant are among some of the things needed to prevent fire and explosions.
As with all of our blogs, we focus primarily on extraction – official called Local Exhaust Ventilation (LEV)
In the example of a paper mill, paper dust can build up during the manufacturing processes – such as the web running over rollers, slitting and cutting, sheets hitting stops and more. Where areas of dust build up are identified then a LEV system to remove the dust is required. The dust should be extracted as close to the source as possible and removed by suitable duct work to a dust extractor/ collector. The entire LEV system needs to allow for explosion relief and possible fire control. The collector should be away from buildings and also make considerations for fire control and explosive relief.
The LEV itself could also potentially be an ignition source. Fans can run hot and if there are in the contaminated air stream then they could pose a risk. Additional controls such as spark proof fans should also be considered.
The HSE recommend that such systems be designed and built by experts.
For more advice give us a call on 01489 899070 or Contact Us. We are happy to talk to you about your application and offer advise and services for your extraction.
HSE Documenation: Paper Mills. Guidance on Fire Risk
