22 Feb What employers can do to control industrial dust and fume hazards.
New dust & fume regulations are in effect, is your work site compliant?
In many cases, similar principles of control and suppression apply to welding fumes and other airborne pollutants, such as dust (dust is made up of solid particles ranging in size from 1 µm up to around 100 µm, which may be airborne). Unless dust and fumes and other airborne pollutants are removed from the air, they’ll move with the air and reach employees who are away from the source, this is called unexpected exposure and is a workplace hazard some work sites don’t consider. Damp materials are less likely to release airborne dust, but of course, this does not apply if they dry up later. Oil mist can carry pollutants in the air for quite some distance. Any airborne contaminants in the workplace constitute real health hazards for employees, and the possibility of a fire or explosion from the same contaminants makes this situation much worse than might be anticipated. As well, recently instituted regulations in Manitoba call for more stringent air quality control measures, particularly in welding shops.
The World Health Organization has recognized workplace dust and fumes as a significant hazard that all businesses should plan for and address in their safety and health planning. Specifically, OSHA in the US has produced recommendations for exposure limits, which were recently accepted and implemented in Manitoba by Workplace Safety & Health (the concern being primarily for welders and manganese in welding fumes). Section 17 & Section 36.5(1)a) of the regulations states “in the case of an airborne substance for which the ACGIH has established a threshold limit value, establish an occupational exposure limit for the substance that does not exceed the threshold limit value established by the ACGIH”.
It sounds confusing but it’s simply stating that exposure levels to certain pollutants need to be below defined limits. Or to put it another way, businesses are now required to provide acceptable levels of clean air, as free from pollutants and toxins as possible, in the workplace. So let’s get started on figuring out what that means for you and your business.
Examples of hazardous dust and fumes in the workplace
This is by no means an exhaustive list of potential dust and fume hazards but it does give you an idea what constitutes a dust/fume hazard and where they can develop. Chances are, if you’re reading this, you already realize your workplace has concerns and know what process is generating them. Of course, each work place should do their own evaluation to determine their own levels of dust/fumes/pollutants in the workplace. There is air quality testing firms that can help with this. This list might make you aware of other air pollutants and hazards you haven’t thought of:
- Mineral dusts from the extraction and processing of minerals (these often contain silica, which is particularly dangerous),
- Metallic dusts, such as manganese, lead and cadmium and their compounds,
- Other chemical dusts, such as bulk chemicals and pesticides,
- Vegetable dusts, such as wood or grains (this type of dust may also contain moulds and spores),
- Welding fumes,
- Grinding processes,
- Oil mist runoff.
Here is a list of some of the more common working environments where excess dust can create a real problem.
- Mines and quarries – dust from coal, flint and silica,
- Construction sites – dust from cement and asbestos,
- Welding – fumes from welders generate many toxic gases that need to be removed,
- Manufacturing processes – dust and air borne particles from fiberglass, metals, and ceramics,
- Farming and Agriculture – dust from grain,
- Carpentry and Joinery – dust from wood,
- Bakeries and mills – dust from flour,
- Textiles – dust from materials like leather or feathers.
Dangers of Dust and Fumes
Two primary dangers of dust and fumes in the workplace are explosions and prolonged exposure hazards. Control, preventative measures, and good housekeeping are required to diminish both of these dangers.
Occupational Health and Safety defines combustible dust as any fine particulate that has the ability to catch fire and explode when exposed to air. Dust that floats in the air has oxygen surrounding every particle, providing two of the three conditions necessary for fire, fuel to burn and plenty of oxygen. The third requirement, heat, can come in many forms but a single small spark is all that is needed to start a combustible dust fire. Explosions can have an additional element, confinement, where pressure builds, though that isn’t necessary for an explosion to occur, it will increase its severity.
Dust explosions may be classified as being either “primary” or “secondary” in nature. Primary dust explosions may occur inside equipment or similar enclosures and are generally controlled by pressure relief through purpose-built ducting. Secondary dust explosions are the result of dust accumulation inside a building being disturbed and ignited by the primary explosion, resulting in a much more dangerous uncontrolled explosion inside the workplace. Historically, fatalities from dust explosions have been the result of secondary dust explosions and not primary ones. Think of the primary explosion as the match that lights the much larger explosion. Neither is desirable.
In the air and on surfaces can result in allergies, intolerance, sickness from short-term exposure and disease from prolonged exposure to pollutants. OHS has a fact sheet here concerning the effects of organic dust on lungs of exposed workers that is worth a read. For air quality purposes we also need to consider chemical dust/fumes that can cause cancer or acute toxic effects found in manufacturing processes – these type of pollutant needs to be captured and controlled more rigorously than other pollutants and we’ll speak to specific methods later.
Welding fumes containing manganese have come under intense scrutiny lately and there are now regulations in place to greatly reduced exposure levels of manganese and many businesses are having to develop new air cleaning solutions. Adjusting to the new regulations have proven to be difficult as many people are unaware of the tools and products to retrofitting facilities with new air cleaning technologies. Some weld shops have adjusted their materials to reduce or eliminate manganese but that’s not a viable alternative for all businesses (particularly stainless steel shops).
What does this mean to the business owner?
The Canada Labour Code is designed to reduce all dangers to workers, including dust, in the workplace. Employers are required to eliminate or, at least, disperse the dust sufficiently so it doesn’t pose a hazard to employees. The level of control required is determined by the industry, the type of dust generated, and the work site. The onus is on the employer to provide a safe working environment, regardless of the industry, that doesn’t endanger the worker.
Proper exhaustion and filtration of the air is your best preventative measure for health related issues. In certain occupations where dust is a fundamental aspect, employers need to provide the correct personal protective gear and with breathing respirators if needed (dust masks have been proven to be largely ineffective at preventing exposure to dust hazards in the air).
As well, any manufacturing or industrial process that generates dust should be inspected often for dust build up and the dust removed properly with equipment built for that purpose. Manitoba businesses can be subject to costly “Orders to Improve” if regulations are not bring met, with operations being shuttered while improvements are made to the work site. Your best bet as a business to minimize disruptions and downtime is to plan ahead and invest in the necessary equipment. While the initial outlay for equipment may seem costly the long term health benefits to workers, regulatory compliance, and reduced sick days far outweigh the costs.
Another way to mitigate worker health issues is through health monitoring. Are your ensuring that workers undergo regular health checks from a doctor which might pinpoint any early signs of illness? If dust and fumes are a component of your work environment this is your way to catch, and possibly prevent, a major illness in your workers. The physician should be made aware of the profession of the worker and be aware of typical problems with the profession in question.
Upgrading your Ventilation System
Your current ventilation system may not have been built to accommodate the work you are currently doing or may be insufficient for growing firms or doesn’t meet the new regulations. Luckily there are many options and strategies you can implement to provide better air quality in a cost effective manner. Many measures can be applied to new OR existing buildings without extensive and expensive retrofitting. As well, workstation specific strategies may suit your operation better. In part two of this series of posts, we explore your many options for equipment to improve industrial air quality.