In environments where barley, corn, maize, wheat, rye, and oats are processed, a coarse, fibrous dust is generated with the potential to create explosive atmospheres. Dust control is essential to ensure the health and safety of the employees and the environment as well as preventing dust explosions.
All types of dust collectors from cyclones to cartridge or fabric filters can be applied to capture dust from the milling process. Dust can be returned to the process or removed from the process as completely as possible. The effectiveness of the systems can drop significantly if you introduce irregular elements such as wet compressed air or a change in the process.
Damaging Effects Of Grain Dust
The dust generated by milling, storage and transportation can build in large amounts. When a minimum explosive concentration is reached after mixing with the air, ignition can occur if it makes contact with a fire source, causing severe economic loss, injury or loss of life. Risk of explosive combustion differs with the size of the dust particles. Finer dust will catch fire easier, and will result in a more explosive atmosphere. There are four main requirements for the explosion of grain dust.
The dust is combustible.
Airborne dust concentration is greater than the minimum explosion concentration.
The energy of the source of ignition is sufficient to ignite the combustion wave.
A sufficiently closed-off area with enough oxygen to maintain combustion.
Dust diffusion leads to a greater size of dust particles in the air, which will affect the production operation of the workers. Production machinery and equipment may be corroded and fail through dust adsorption and flutter, resulting in the cost of production increasing and working efficiency being reduced.
How Can Grain Dust Harm Your Health?
Grain dust is a respiratory sensitiser and, when inhaled, can cause an allergic reaction in the respiratory system. Any subsequent exposure, may cause respiratory illness, even in very small amounts.
Short-term effects can include:
watery/prickly eyes (conjunctivitis);
runny/stuffy nose (rhinitis);
grain fever/organic dust toxic syndrome (a short-lived ‘flu-like’ illness).
Long-term effects may lead to more serious respiratory problems, such as:
asthma (coughing, wheezing, chest tightness);
chronic bronchitis (cough, phlegm production);
chronic obstructive pulmonary disease(COPD, a long-term illness making breathing difficult);
farmer’s lung (increasing shortness of breath and weight loss).
What Are The Exposure Limits Of Grain Dust In The Workplace?
The Control of Substances Hazardous to Health (COSHH) Regulations 2002 require that you protect workers from the hazards of grain dust due to the health dangers. The long-term Workplace Exposure Limit (WEL) for grain dust has been set to 10mg/m3 (averaged over 8 hours) with a short-term limit of 30mg/m3 (averaged over 15 minutes). The employee’s exposure to grain dust must be reduced to ‘as low as reasonably practical’ due to chronic health effects associated with it.
Control Of Exposure To Grain Dust
In the event that it is impossible or impractical to fully prevent exposure to grain dust, you must follow these good practice principles in order to effectively control exposure. Grain dust exposure can be controlled through a variety of methods, which may include:
reducing grain dust at the source by making changes to processes and activities;
enclosing the process;
Local Exhaust Ventilation (LEV);
good general ventilation;
minimising the number of exposed employees;
minimising the duration, frequency and level of exposure;
handling materials properly;
maintaining plant and equipment properly;
good housekeeping principles (don’t use a brush or compressed air, and never use compressed air to remove dust from clothing);
employee training on the use of control measures.
Dust clouds, settled dust on floors, ledges and machines, or machinery leaking dust would indicate a problem that requires action to be taken to reduce dust at source. The fine dust which will cause most harm, and that you can breathe into the deep recesses of your lungs, is usually imperceptible to the naked eye.
What Can RCS Do For You
RCS's engineers will endeavour to provide you with the most effective and cost-efficient solution for grain dust extraction and filtration in partnership with Donaldson. Call us on +44(0)1563 546807 or click here to contact us for more information.