Combustible Dust Remediation with Encapsulating Foam


Our specialized and enhanced DEFA foaming process can safely remove combustible, explosive, and fugitive dust.


The Process

The Dust Encapsulating Foaming Agent (DEFA) process propels a relatively low pressure, copious stream of nearly-dry foam onto hard to reach interior walls and ceilings of industrial facilities including coal-fired power plants. After it’s applied, the DEFA foam travels down from the walls, ceiling, girders and framework while attracting dust like a magnet. It then carries the dust deposits directly to the floor. After the foam dissipates, it is swept away.

Ideal for Coal Dust

DEFA is ideal for cleaning any kind of coal dust, especially PRB, which can be exceptionally explosive under various conditions. Routine cleaning around volatile coal dust areas such as the tripper room is an important safety precaution and provides peace of mind to your company and employees. Safely and cost-effectively mitigate dust to comply with NFPA and OSHA regulations and directives.

The Reach

The DEFA foaming process offers a remarkable spray and coverage range. Assuming the unit is positioned in the middle of the cleaning area, up to 150 lineal feet of area and 35-50’ in height is reached without moving the unit. Should the unit need to be re-positioned, it is portable and on pneumatic wheels.

This process delivers a relatively low pressure, copious stream of nearly-dry foam to hard to reach walls and ceilings.

View OSHA’s Standards for Combustible Dust
View NFPA’s Standard for the prevention of fire and dust explosion

Safely and cost-effectively mitigate dust.


  Portable and Ultra Efficient

  Safely Removes Combustible, Explosive and Fugitive Dust

  Will significantly help achieve NFPA and OSHA Compliance

  Reaches High/Remote Areas of Removal

  Environmentally friendly foaming agent


  Coal Fired Electric Generation

  Chemical Manufacturing

  Fibrous Material Manufacturers

  Industrial Inorganic Chemicals

  Manufacturing Industries

  Mechanical Rubber Goods



  Motor Vehicle

  Manufacturing Facilities



  Refuse Systems


  Soap and Detergents

  Tire Manufacturers

  Wood & Reconstituted

  Wood Products


  Extruding Manufacturers

Case Study


A western Kentucky utility plant was exploring alternative options to cleaning their tripper room. Historically they had utilized a traditional combination of routine sweeping and industrial vacuuming to mitigate the combustible dust hazards present. Cleaning the ceiling and supports of the tripper room roof also presented a superior challenge as this area was not accessible by man-lift and scaffolding costs were extreme. These methods of cleaning were highly labor intensive and time consuming for an area that needed daily attention. This facility needed a safe and efficient way of getting the combustible dust hazard in this area under control.


Utilizing Thompson’s unique and custom-designed, proprietary foaming equipment and dust-encapsulating foaming agent, the Thompson 3-man crew was able to clean all of the tripper room walls, supports, and 30’ ceiling with never having to lift their boots off the tripper room floor.


Thompson’s Combustible Dust Remediation Services (CDRS) freed up 96 man-hours of in-house labor with just one cleaning. Additionally, Thompson’s CDRS crew was able to safely remove combustible dust from areas of the tripper room that had been traditionally “un-reachable” and completed this task without the use of scaffolding, ladders, or a man-lift.

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