Where is Dust Likely to Occur?
Dust can be a problem in almost any industry. The hazards of dusts like silica and wood are well recognised, but there are many more substances that generate dusts which are hazardous to health. Exposure to all such dusts needs to be prevented or, where this is not reasonably practicable, adequately controlled.
Many work activities can create dust. Some examples are:
filling bags or emptying them into skips or other containers
weighing loose powders
cutting, eg paving stones
sieving and screening operations
conveying materials by mechanical means or by hand
stockpiling large volumes of processed materials
crushing and grading
milling, grinding, sanding down or other similar operations
cleaning and maintenance work
feeding livestock from bags or conveyor systems
clearing up spillages
Do You Have a Problem With Dust at Work?
Some simple checks may help in identifying whether a problem exists:
Is the material naturally dusty?
Does the work you do create dust by mechanical or other means?
Is dust liable to be disturbed?
Visible dust on pipes, surfaces, ledges etc. may indicate the presence of airborne dust. However, many dust particles are too fine to be visible under normal lighting conditions. A dust lamp, which provides a powerful beam of light, can be used as a quick method to show whether a fine dust is present, and helps to pinpoint the sources and movements of such dust.
What Are the Effects on Health?
Exposure to any dust in excessive amounts can create respiratory problems.
The harmful effects of dust can vary, from skin irritation to lung cancer, depending on the composition of the dust and the type and degree of exposure.
Dust is not always an obvious hazard because the particles which cause the most damage are often invisible to the naked eye and the health effects of exposure can take years to develop.
Dust that can enter the nose and mouth during breathing is referred to as ‘Total Inhalable Dust’. Some dust may consist of larger or heavier particles that tend to get trapped in the nose, mouth, throat or upper respiratory tract where they can cause damage.
Dust particles that are small enough to be breathed into the lungs are called ‘Respirable Dusts’; these dusts can build up in the air spaces in the lungs and can lead to lung damage.
The build up of any dust in the lungs could produce lung damage with inflammation and eventually fibrosis (scar tissue). This could lead to breathing impairment. These conditions usually develop slowly, so symptoms may not appear until severe irreversible changes have taken place.
Some dusts can cause ulceration of the skin, and irritation, skin sensitisation and dermatitis can be caused by dusts such as epoxy resins, rubber processing chemicals, wood dust and fibreglass.
Dust particles produced during the cutting, grinding and drilling of materials can cause eye damage/irritation, and some dusts may cause eye damage/irritation due to their chemical nature.
Some inhaled dusts can become trapped in the mucus that lines the respiratory tract. This mucus tends to be either spat out or swallowed.
Inhaled dusts can get into the digestive tract, where they can cause local effects such as gastrointestinal tract irritation. Alternatively, they can enter the bloodstream and produce effects in other organs and tissues.
Prevention and control of exposure
Never assume that any dust is safe. All uncontrolled dusts are potentially hazardous. In particular, any uncontrolled dry process or dusty work activity, especially in an enclosed environment, is likely to create a dust problem.
Dust Exposure Prevention
Prevention of exposure to dust should be the first objective. Many forms of dust can be eliminated from the workplace. Examples of how this can be done include:
eliminating dust by using special cutting techniques rather than by grinding or sawing, or by using wet-cutting processes
using less toxic materials, eg powdered alumina instead of flint or quartz as in the pottery industry
using pellets rather than dusty powder
using dust-suppressed materials and emulsions or pastes rather than mixing dry constituents
Where substitute materials are used, employers need to ensure that these pose less of a health risk and that exposure is controlled in accordance with the provisions of COSHH.
Control measures usually involve a combination of equipment and ways of working to reduce exposure. In order of priority the right combination of control measures could include:
Eliminate the use of a harmful product or substance and use a safer one.
Use a safer form of the product, eg paste rather than powder.
Change the process to emit less of the substance.
Enclose the process so that dust does not escape.
Extract dust emissions near the source.
Minimise the number of workers that are at risk.
Apply suitable administrative controls, such as reducing the length of time that workers are exposed to dust.
Provide personal protective equipment (PPE) such as gloves, coveralls and a respirator.
Remember that PPE should only be considered as a control measure as a last resort. Other control measures should always be given priority.
Control of Exposure
Where it is not reasonably practicable to prevent exposure to dust, a combination of engineering and process controls may be appropriate. These include:
segregating the dusty processes
providing extraction by LEV
using mechanical handling systems and closed containers
damping down materials
providing a good standard of ventilation
using a vacuum cleaner or a wet method to keep floors and surfaces clean. Avoid using compressed air or dry sweeping
Local Exhaust Ventilation (LEV)
LEV systems should be built into, and designed for, the process that creates the dust.
If you use LEV to control exposure, it needs regular checking and Thorough Examination and Testing at least once every 14 months. Whoever does the work must be competent, i.e. have the necessary skills, knowledge and experience.
What Can RCS Do For You?
RCS's fully qualified and experienced engineers can design, install, test and maintain your LEV extraction systems.
RCS's engineers will endeavour to provide you with the most effective and cost-efficient solution for dust extraction, fully COSSH compliant, following current HSE guidelines and your own individual requirements. Call us on +44(0)1563 546807 or click here to contact us for more information.