Table of Contents
- What to Know About Dust Control & Regulatory Compliance
- What Causes Dust in Aggregate Operations?
- Types of Dust Suppression Systems
- Dust Suppression Equipment Options
- How Mobile Dust Cannons Work
- Site-Specific Dust Suppression Application
- Six Questions to Ask to Get the Right Dust Suppression Solution
Let’s talk dust control. Dust affects visibility, worker exposure, neighboring properties and the way the whole site runs. It comes off haul roads. It kicks up around stockpiles. It shows up at crushers, screens, transfer points and anywhere dry material is being moved.
Dust suppression systems are a key part of any aggregate operation, as they protect workers from airborne particles, help keep sites clean, and reduce concerns about dust leaving the site. Also, new MSHA regulations have recently come into effect, reducing the silica dust exposure levels allowed for worker safety. You may be wondering what this means for your day-to-day operations.
Here at Thompson Equipment, we help producers stop guessing at dust control and start matching the right suppression system to the site and the conditions driving the problem. Before getting into equipment options, it helps to understand why MSHA’s silica rule has put dust suppression in focus for aggregate operations.
What to Know About Dust Control & Regulatory Compliance
Aggregate materials often contain silica, and operations such as crushing and screening can generate silica dust, a long-term hazard to worker health. Suppressing silica dust and preventing workers from inhaling it are primary safety and health issues for operators. In addition to protecting workers, dust suppression methods improve site visibility and are now being driven by stricter regulatory requirements.
Aggregate producers have always dealt with dust. That part is not new, but recent interest in dust suppression has grown in an effort to protect employees and comply with these important regulations. MSHA’s 2024 respirable crystalline silica rule increased attention on exposure levels, monitoring and dust control. The rule set a permissible exposure limit of 50 micrograms per cubic meter of air and an action level of 25 micrograms per cubic meter, both calculated as an 8-hour time-weighted average.
In April 2026, MSHA announced that enforcement of the rule was stayed by a federal court order while legal challenges continue. As a result, operators should monitor ongoing court proceedings and review the latest MSHA guidance around the rule’s enforcement timeline.
Even with this recent enforcement status, the direction is clear: dust is a site issue producers need to take seriously.
What Causes Dust in Aggregate Operations?
Dust can come from almost every part of an aggregate site. Some sources are tied directly to production, while others come from traffic, weather and exposed material, including:
- Rock crushing (primary, secondary, and tertiary)
- Screening operations
- Transfer points and conveyors
- Stockpiles (wind erosion)
- Haul roads and mobile traffic areas
Because airborne and fugitive dust can be generated throughout the aggregate mining process, aggregate dust control usually takes more than one tool.
Types of Dust Suppression Systems
There’s a wide range of dust suppression systems, from engineering controls integrated into equipment to mobile dust cannons and wet suppression systems. As each site is different, your system should be customized to meet the specific needs of the operation.
The following suppression system types can be mixed and matched to help improve dust control:
- Spray-based dust suppression systems - These systems use water spray nozzles to help prevent dust from becoming airborne and can be added to conveyors and crushing stations to help control dust at its source.
- Mobile dust cannons – Dust cannons use a fan, a pump, and a fine mist of water to dampen dust in the air. The water attaches to dust particles and helps pull them out of the air.
- Fogging or misting systems – Similar to other dust control spray equipment, they spray a fine mist of water at specific production points. For example, a misting ring can be attached to discharge points on conveyors or chutes.
- Chemical dust suppression solutions - Chemical dust suppression solutions break the surface area of water droplets, allowing them to trap more dust with the same amount of liquid. They also create a microscopic film that covers the dust and the ground, helping prevent dust from becoming airborne in the first place.
- Dry dust collection systems - These systems focus on physically containing dust at its source and can be added to or may be an integral part of a piece of equipment. An example is a dust cover that blocks dust from becoming airborne.
Dust Suppression Equipment Options
In the New England region, late spring and summer are when site dust suppression is most needed due to hot, dry, and windy conditions. Spray systems, such as mobile dust cannons, are most effective at containing dust during aggregate operations in this area.
How Mobile Dust Cannons Work
Dust cannons work like snow-making equipment for ski resorts. A large fan projects fine mist or atomized water, which attaches to airborne dust, weighs it down, and causes it to fall to the ground.
Most cannons can oscillate or sweep side to side to cover a wider area (up to 350 degrees) or focus on a specific location or process. By adjusting elevation, oscillation, and spray size, operators can target specific processes or stages in aggregate production.
Source: ScreenPod
Pro Dust Cannon Tip: If there’s a crosswind, operators should position the unit to take advantage of the wind's direction. Knowing your site’s prevailing wind patterns can help you position them in the best location for wider coverage, but adjustments may be needed if conditions change.
On an aggregate site, this flexibility matters. A dusty environment is not static. One hour, the issue may be around a stockpile. Later in the day, a crosswind may start carrying dust from a different area. That’s why dust cannons are a practical option, with features that make them well suited for changing site conditions:
Trailer-mounted units can be moved around as the dust source, production activities, traffic routes, and wind direction change. This is crucial when working on aggregate sites where conditions are fluid.
Integrated water tanks allow for mobile deployment without a constant water source. Tanks can be filled off-site from nearby resources.
Self-powered equipment has on-board diesel power designed to run the pumps and generators, so you don’t need to worry about separate power sources.
Thompson Equipment works with 3R Machinery to provide ScreenPod dust cannons. These cannons are portable, trailer-mounted, self-powered, and equipped with integrated water tanks. The double-axle trailer units connect with a pintle hitch and can be pulled by a commercial truck, such as a 550-class, backed into position, and filled with water. These units enable you to harness the wind to your advantage and don’t lock you into a single fixed coverage pattern.
ScreenPod offers a deep catalog of different site dust suppression solutions, including the following:
| Equipment Type | Best Fit |
| Static dust cannons, such as ScreenPod S45 or S65 units | Fixed dust areas where the site layout is steady and the unit can become part of the daily startup routine |
| Telescopic dust cannons, such as the ScreenPod S45 Telescopic | Areas that need extra height or reach to cover a defined dust zone |
| Tracked dust cannons, such as the ScreenPod S65 Teletrack | Sites that need a self-contained unit to move across uneven ground without being towed |
| Trailer-mounted dust cannons, such as the ScreenPod S45T 2000L or S45RT 6000L | Quarries, pits and aggregate sites that need portable coverage, onboard water and flexible placement |
For many aggregate producers, trailer-mounted units are a practical starting point. They let crews test where the cannon works best, move it around the site and adjust based on wind, water access and production activity.
If you're not sure which approach makes the most sense for your site, reach out to our team. We can help you look at your operation, talk through the dust challenges you're dealing with and figure out what equipment is likely to work best in the field.
Site-Specific Dust Suppression Applications
Every site is different, but most aggregate operations deal with a few common dust zones. Here are some suggestions to help you choose the right dust suppression system for your needs:
Quarry Dust Suppression
Dust suppression for quarries includes using dust cannons or fixed misting rings to help control dust during specific processes, such as crushing, material transfer, and screening, where large amounts of dust are created.
Stockpile Dust Control
For active stockpiles, atomized mist cannons with chemical wetting agents help the water and dust bind more effectively. Storage stockpiles can use chemical crusting agents to create a hard shell over the materials.
Haul Road Dust Control
Haul roads are one of the most obvious dust sources on an aggregate site. Rubber tires moving across dry, unpaved roads can kick up a lot of dust fast.
Water trucks are a common solution. Many quarries already have them running during dry weather to wet down commonly used roads. Depending on the site, chemical dust suppression may also be considered to help bind fine particles or hold moisture longer.
A dust cannon will not replace every haul road control, but it can support broader dust control measures where traffic, wind and material handling are all contributing to airborne dust.
Safety Tip: Keeping haul road dust down also supports the bigger safety picture on site, especially where trucks, loaders and crews are moving through the same work areas. For more info, read our guide to quarry heavy equipment safety.
Crushing & Screening Dust Control
Crushing and screening create dust because the material is being reduced, sorted, dropped and transferred. Dust control spray equipment may be used at crushers, screens, conveyors, chutes and transfer points. Covers, curtains, skirting and containment can also help keep dust from escaping.
Mobile dust cannons can support those systems by reducing dust that becomes airborne around the processing area. The best setup may use sprays at the source and a mobile cannon where dust is traveling.
Six Questions to Ask to Get the Right Dust Suppression Solution
Choosing dust suppression equipment should start with the site, not the spec sheet. When choosing the right dust suppression solution, consider the following:
What is causing high dust levels?
Identify the specific processes or locations that are creating airborne dust.
Where is the dust going?
Wind, truck traffic and site layout can carry it into work zones, across roads or toward neighboring properties.
Is the dust source fixed or moving?
If the source is moving, you’ll need mobile suppression equipment, either trailer-mounted or tracked.
What does the wind usually do?
The wind may not come from the same direction every day, but many quarries have a prevailing wind most of the time.
Is water available?
Some sites have clean water available from wells, ponds or other sources. Others rely on water trucks.
Is power available?
If the equipment needs to work away from the plant or fixed infrastructure, self-powered operation may be the better fit.
For aggregate producers, dust suppression is part of the larger equipment conversation.
As your trusted supplier of aggregate processing equipment, Thompson is here as your partner in dust suppression system selection and implementation. Contact our team of experts for help selecting and buying the right equipment for the job.