Raising the bar for fumigation agrochemicals

A crucial part of food resource protection

While most of us don’t realize it, products that are stored and shipped across the world generally need to be fumigated first — especially food commodities such as grains, nuts and fresh produce. Solvay plans to leverage digital technologies to further improve the fumigation process, for more effective control of quarantine pests, as explains Mike DePalo, the Global Business Director of Phosphine Gases at Solvay’s Technology Solutions.

A post-harvest, pre-shipment process

First of all, what is the purpose of fumigation?

Fumigation is an important part of agricultural resource protection, used for the short-term or long-term storage of commodities such as grain, nuts and fruit, as well as non-food products like logs, or even tires. There is domestic fumigation, where commodities destined to supply in-country demands are treated to eliminate insects. International trade requires fumigation to not only eliminate pest but to also to prevent quarantine insects (insects not found in the country of import) from crossing borders during shipping. These fumigations are often done at ports, storage locations or processing facilities just before shipment overseas.

Where is Solvay active in this market?

When one thinks of pesticides, it often applies to agrochemicals that are used on soil (pre-plant) or on growing plants and trees (in-field). We’re involved in the post-harvest segment of the agricultural value chain, which is a relatively small segment part of an otherwise large agrochemical market. Crops are harvested, often processed and placed into storage where stored product insects take up residence. Fumigants are used to eliminate these pest ensuring that finished goods sold to consumers are insect-free. Solvay offers two premium products for this market: ECO2FUME® and VAPORPH3OS®. In both cases, phosphine gas is the active ingredient. Our products are often used for high-value product protection like nuts and dried fruit. They are also used to protect stored grain by users who enforce the assurance of a high quality standard for their products The most commonly used fumigation solutions we’re up against are:

• Metal Phosphides: aluminum phosphide and magnesium phosphide. It’s an old technology, well entrenched, that comes with the added challenges of adherence to fumigation protocols, risk of fire, confined space entry and toxic waste by-product with residue issues.
• Methyl bromide: banned for most uses by the Montreal Protocol due to being an ozone depleter. Remains available for quarantine and pre-shipment uses with few current regulatory drivers to replace. But it comprises safety risks as it’s odourless with chronic health implications, and the available personal monitoring detection technology is limited. It also presents challenges with residual levels on commodities and reduced shelf life of certain food commodities if application rates are exceeded.
• Sulfuryl fluoride: effective solution in food processing plants. Challenges include effectiveness in cooler temperatures and food residue levels if application rates are exceeded. It also presents a high environmental risk: it’s a very potent greenhouse gas.

Quicker than most fumigation methods

What are the particularities of phosphine-based fumigation compared to competing solutions?

Our products reach the proper dosage concentrations much faster than metal phosphides, which need time to react. We sell our phosphine as high-pressure gas in cylinders, whereas aluminum and magnesium phosphide come in solid pellet or tablet forms. Flasks of pellets are cheap, easy to transport and have been around a long time, so they’re still the number one choice on the market. The way they work is that you apply pellets into the storage space and often directly onto the product itself. The solid metal phosphide formulations then require ambient heat and moisture to accelerate the reaction and break them down into phosphine gas. The generated gas must then permeate the commodity mass where insects live. Metal phosphides often need an additional day or more to reach the proper dosage concentrations, whereas our products can reach the proper concentration in minutes or hours.

Furthermore, aluminum and magnesium phosphide are dangerous when wet — if contained concentrations of phosphine are high enough, it can result in explosions. Unfortunately these scenarios continue to occur around the world each year. Phosphine itself is highly flammable due to its reactivity with oxygen, but our ready-to-use product ECO2FUME® contains only 2% phosphine, the rest is inert gas, so it has no flammability at all times. As for VAPORPH3OS®, it’s 100% pure phosphine, so it’s very flammable as a stand alone product. It’s designed however to be used with high tech equipment that dilutes the gas to 1% phosphine on site, rendering it a non flammable fumigant mixture. Given the nature of fumigants, only specialized and duly licensed and trained companies have access and authorization to use them.

Originally published at https://www.solvay.com