Dust suppression is an essential practice to safeguard health and the environment. Our resource guide covers everything that you need to know about dust suppressants and dust abatement products.
Silica dust consists of tiny particulate matter of crystalline silica, a common mineral found in rock, sand, and concrete. When these materials are disturbed, the silica particles become airborne and create hazards.
Silica dust is fugitive dust and should be suppressed to minimize risks.
Fugitive dust is created from many sources, including construction sites, mining, unpaved roads, and agriculture. It can carry a variety of pollutants, including heavy metals and organic compounds. These pollutants pose health risks to humans and animals and contribute to environmental issues like soil degradation and water contamination.
The negative impacts of fugitive dust make it necessary for industries to adopt effective dust control measures.
Neglecting to implement dust suppression product measures on your gravel roads and work sites can lead to various hazards.
Health
Workers who are exposed to dust over a prolonged period are at risk of developing health issues. Issues may include respiratory problems like coughing, shortness of breath, asthma, and, in severe cases, lung cancer and disability.
To ensure the well-being of workers, OSHA in the US and COHSR in Canada has implemented regulations that require employers to implement effective dust suppression measures. It is important to understand that compliance with these rules is mandatory, not optional. Failing to comply can lead to substantial fines.
Review the OSHA standards at the following link: https://www.osha.gov/silica-crystalline.
Each province in Canada has its own set of regulations. Visit the following link for a general guideline: https://www.ccohs.ca/oshanswers/chemicals/chem_profiles/quartz_silica.html#section-10-hdr.
Erosion
The loss of fine particles results in the instability of gravel roads, causing them to fail, resulting in rutting, potholes, and costly gravel replacement.
Equipment DamageDust's abrasive nature can gradually damage equipment. The abrasiveness can compromise the equipment's structural integrity and operational functionality, leading to potential performance issues and the need for repairs or replacement. Dust accumulation can also clog up filters and requires regular cleaning causing increased maintenance cost.
Reduced Visibility
Dust accumulation on roads can severely diminish visibility, making it challenging for drivers to see clearly around hills, curves, and junctions. This hazard becomes particularly concerning in areas where fugitive dust is generated frequently, potentially hindering safe navigation.
Environment
Wind can migrate dust into the surrounding environment and nearby waterbodies, impacting water quality and aquatic communities. Fugitive dust also settles on nearby vegetation, reducing crop yields, and weakening plants.
What is hygroscopic?
Hygroscopic refers to the property and ability to absorb and hold onto water from the surrounding atmosphere.
Magnesium and calcium chloride are the preferred dust suppressant liquids because they are hygroscopic. They act like sponges, attracting moisture from the air and bind water to the fines, which prevents dust particles from becoming airborne.
The two chlorides' hygroscopic nature allows them to remain effective for an extended period, continue to attract moisture and maintain dust suppression even in dry conditions.
Which dust suppressant product is best for gravel roads?
According to a 2013 survey conducted by the Federal Highway Administration, magnesium and calcium chloride are the most common choices to suppress dust.
The main driver behind this choice is the economics of the product's effectiveness, longevity, and availability.
Both magnesium and calcium chloride are hygroscopic and have similar properties. Calcium is a 35% contributor to dust suppression chemicals, and magnesium chloride is 30%. Due to their molecular weight, the two are equivalent, and there is no difference in how they perform despite their different concentrations. Both are important ingredients of dust suppression products.
What is the correct application rate when using calcium or magnesium chloride as a dust suppressant?
The application rates for calcium and magnesium chloride are the same for both products. The correct rate for both products is between 0.25 and 0.3 gallon per square yard / .95 and 1.1 liter per kilometer.
Before applying calcium or magnesium, pre-wet the road with water. This will draw the dust suppressant liquid into the gravel to form a tighter surface bond and allow you to achieve long-lasting performance.
It's essential to follow best practices to achieve effective road dust suppression. Here are our top ten tips to help you succeed in your road dust suppression program:
Preparation
Application
