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How It Works

How FumoFlow grain shed fumigation works

The recirculating and ventilating system designed to make grain fumigation faster, safer, easier – and more effective.

The patent-pending FumoFlow grain shed is a purpose-built concrete panel grain shed that uses a tarp on a pulley system to seal the shed, and a recirculation duct and fan system to recirculate fumigant and then vent post-fumigation.

The system can be used by growers and by licensed fumigation contractors.

Tarped grain stack in FumoFlow shed

FumoFlow Grain Shed Fumigation

How it works, step-by-step.

1. Grain is stored on the shed floor

Grain is handled like in a standard Action grain shed, loaded and stacked on the concrete floor.

2. The shed is sealed for fumigation

A custom fumigation tarp is pulled across the grain stack using a pulley system. The tarp seals to custom flashings at the top of the wall panels.

3. Fumigant is released through designated entry points

Fumigant is released using the method growers already use, such as blankets or tablets. Cylinderised gas can also be used by licensed fumigation contractors such as Grain Protect.

4. Recirculation moves gas through the grain stack

Recirculation boxes and fan inlets on the side of the shed blow Phosphine out over the top of the grain, under the tarp.

The fans continuously draw gas from vents in the lower part of select wall panels and push it back through ducts in the upper part of the concrete panels, and under the tarp.

As a result, the fumigant is quickly and evenly distributed through the grain bulk. The fumigant reaches required concentration levels faster and consistently across the stack, helping avoid dead zones.

5. Concentration is held for the required exposure period

Once the required concentration level is reached across the stack, the fans are switched off and the grain held in the shed for the required exposure period.

6. Venting is managed after fumigation

Once fumigation is complete, the same fan system is used for controlled venting to reduce residual gas and help meet exposure limits faster.

What Is Included In A FumoFlow Grain Shed?

A FumoFlow grain shed includes:

Action grain shed design with concrete panels, a 21-degree roof pitch and adequate height for tipping inside the shed if required.

Recirculation boxes with fan and duct system installed to custom concrete panels

Overhead tarp pulley system with custom sized tarp

Custom panel flashing and sealing system for safer, easier and quicker tarping.

Developed By Action Steel

Patent-pending FumoFlow grain sheds are designed, manufactured and installed by Action, your trusted farm shed company. 

How Was The Grain Shed Fumigation System Tested?

FumoFlow grain shed testing began in February 2026 after more than 18 months of R&D, and is ongoing.

The testing includes two stages:

Fumigation with cylinderised gas
Fumigation with solid form phosphine

The purpose of the two stages is to test the effectiveness of the FumoFlow system using different methods and provide meaningful data for growers and fumigation contractors.

The tests measure the time the FumoFlow system to reach:

  • Required concentration levels when fumigating
  • Compliant exposure limits when venting

Monitors in multiple locations in and around the shed record the data. 

The testing is conducted in conjunction with the grower, Kerry Miles of Grain Protect, and Chris Warrick of Primary Business, to ensure unbiased and professional testing conditions, and therefore accurate and meaningful test results.

FAQs

How Does FumoFlow Work? Your Questions – Answered

A FumoFlow grain shed is designed to support the main fumigants used in grain storage, subject to the grain type, market requirements and label directions. Phosphine remains the main on-farm fumigant, while sulfuryl fluoride may also be used in some cereal grain applications by licensed fumigators.

Where sulfuryl fluoride or methyl bromide are used, active gas recirculation becomes especially important. These fumigants typically require stronger recirculation performance than phosphine to achieve even gas distribution through the grain mass, and FumoFlow is designed to provide that capability.

Test results show that the FumoFlow system reaches required concentration levels and compliant exposure levels faster, reducing the time to treat grain by as much as 50%. Data is still being collated for the white paper – signup via the Enquire form to be notified when this is released.

Recirculation speeds up the fumigation process by reaching the required phosphine gas concentration (required to control pests at all life stages and prevent resistance) faster – in some cases as much as half the time.

No, Action is a farm shed company that designs, manufactures and installs FumoFlow grain sheds. Fumigation is either conducted by the grower or a licensed fumigation contractor such as Grain Protect.

A FumoFlow grain shed consists of a heavy-duty, hot-dip galvanized Action shed frame, which requires little to no maintenance.

The main maintenance consideration is the tarp and the panel flashing.

For example, the tarp lifespan depends on how often it is deployed and how it has been handled over time, particularly whether it has been cut and taped during fumigation and stored correctly.

Routine maintenance typically includes:

  • Inspecting tarp for wear or damage before and after fumigation
  • Checking panel flashing remains intact, sealed and safe to walk on
  • Ensuring fans, ducts and vents are clear and operating correctly

Overall, maintenance is comparable to a standard Action grain shed, with additional checks focused on the tarp and components used during fumigation.

Being purpose-built for treating grain, the FumoFlow system makes the process quicker and easier for both growers and contractors. The most time-consuming task is in tarping the shed, however, once the system is set up, this can be completed in about 30 minutes (the more times you do it, the quicker it becomes!). This does depend on the size of the shed and the number of personnel though.

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