Ecolab's Pulse Fumigation Systems Benefits

Alternative method may be stronger and lower risk than traditional fogging.

This article is taken from the First Quarter 2021 MILLING JOURNAL

Food safety and quality control are vital for mill operators. Consequently, many operators are seeking alternatives to traditional fumigation and fogging treatments to control insect contamination in sifters and other flour processing equipment. A pulse fumigation system (PFS) can help provide a low risk, more effective, and more cost-efficient method of preventing and managing product contamination by pests.

A PFS system uses sulfuryl fluoride, also known as Profume®, as an alternative to spot fumigations, magnesium phosphide, and fogging with Vapona DDVP. PFS is a one-gas fumigant that is applied using a small line that pulses gas up through the bottom of mill rollstands and into the sifter. It is applied at a higher concentration than other fumigantsto achieve an improved kill rate.

Spot Fumigation and Fogging Challenges

Mills can face challenges when using spot fumigation and fogging. One common fumigant, magnesium phosphide, is highly flammable, and gas can be released inside a structure. Gas masks typically are required for licensed fumigators due to safety concerns.

In larger mills, magnesium phosphide product strips are used in high quantities. Strips are placed in each sifter. Sifter knees are marked to identify the location of the strips. With as many as 600 strips in use, it may be difficult to make sure each strip is removed following fumigation. If any strips are not retrieved, there is potential for flour contamination and product recall.

There also are issues with ambient space fogging using Vapona DDVP. There also is potential for odor during application and low efficacy. Equipment reliability has improved with better Vapona canisters.

PFS Safety and Efficacy

PFS sulfuryl fluoride penetrates into confined areas that fogging may not reach. What leaks into open space results in more adult insect kills.

With this method, PFS enters each sifter box via remote and variable control applications. The fumigant is non-flammable, as opposed to magnesium phosphide. There is no risk of losing fumigant inside equipment and no liquid pesticides used inside mill spaces.

Essentially, PFS attacks the flour milling equipment at higher concentrations. With its deep penetration and system saturation, it has a higher efficacy than spot fumigation and fogging. As a general rule, the vast majority of insects inside flour mills are concentrated in small areas. PFS targets and attacks these small areas for more thorough insect kills.

Three-Fold Control Strength

In tests to compare fogging and PFS, researchers observed a threefold reduction in live insects, larvae, and dead insects with PFS. From March to May, when insect activity typically increases, PFS-treated sifters actually saw a reduction in insect numbers.


PFS sulfuryl fluoride penetrates into confined areas that fogging may not reach. What leaks into open space results in more adult insect kills.


Another advantage of PFS is a reduction in rodent activity. With older mills, annual Vapona fogging treatments do not impact rodent populations, but PFS fumigation helps control rodents. Also, sulfuryl fluoride is a non-corrosive gas, which should benefit newer, more automated milling equipment.

Costs of a PFS program are about 20% higher than spot fumigation and fogging treatments, depending on the size of operation. However, it’s easy to see that the effectiveness of the treatments beat traditional methods significantly. While fogging requires at least 24 hours for a full treatment, PFS can be performed in as few as 12 hours.

Larry Stalcup, contributing writer


This article is based on a presentation by Alex Luce, business development manager, Ecolab, Saint Paul, MN (800-352-5326), held mid-September 2020 as part of the IAOM All-District Virtual Conference & Expo. IAOM members who registered for the conference can view the presentation using their provided unique link.