INFORM April 2026

24 INFORM APRIL 2026 , VOL. 37, NO. 4

extract oil from the dehulled soybeans and send the oil to be refined and the remaining soybean meal off for further processing. The dehulling and extracting processes are where most of the hazards come from, in the form of combustible dust and hexane, a solvent used for oil extraction. Hexane is a flammable liquid that, if improperly handled, poses a major hazard. Hexane mixes with soy meal to extract oil and is then evaporated at high temperature to separate it from the extracted oil. The hexane is recovered and used to extract more oil in the future. The potential hazards of hexane mean that processing facilities and operators are extremely cautious using it. The systems used in these facilities are designed with the hazards of hexane in mind. Hexane spills happen, but plant crews usually do a good job of containing them quickly. People know what hexane smells like and know how to respond in case of a spill, so hexane fires are exceptionally rare. “There are tens of thousands of gallons of hexane circulating around all the time and there have been only a couple of significant hexane incidents at soybean facilitities in the past 30 years,” said Williamson. DUST IN THE WIND While the need to take hexane seriously seems obvious, dust is another matter. Dehulling can produce large amounts of dust, as can crushing soybeans to prepare them for oil extraction. If not handled

properly, dust can accumulate around processing equipment. Accumulated dust can catch fire if exposed to an ignition source like an electric spark or heat. In many facilities soybeans are heat treated and dried, which could be a possible ignition source. While piles of dust from poor housekeeping practices are a fire hazard, dust in the air is far more dangerous. Dust suspended in the air will burn quickly, leading to explosions. Since the 1980s there have been hundreds of dust explosions in the United States, leading to serious damage to industrial facilities and hundreds of injuries and deaths. Facilities that work with agricultural products are a major source of combustible dust explosions that the industry has started taking more seriously in the past 20 years. A dust explosion in a Georgia sugar factory in 2008 prompted the National Fire Protection Agency to publish its NFPA 652 standard, which addressed hazards of combustible dust and provided guidance on mitigating those dangers. More recently, in 2024, NFPA released NFPA 660, an updated standard that replaces NFPA 652. To meet NFPA standards facilities must undergo a dust hazard analysis to find areas that need improvement to reduce combustible dust risks. Oilseed processing facilities have large dust collectors that are designed to keep dust

from building up. However, according to Williamson, the design and layout of dust collectors in older facilities is not ideal. Dust collectors should be isolated from each other as a dust explosion can spread through duct work into other parts of the facility. “A lot of older facilities have very big dust collectors that are all interconnected through the whole process,” said Williamson. “There are a lot of changes that need to be made in the prep side of the plant.” AN OUNCE OF PREVENTION Before carrying out upgrades, facilities need to do a dust hazard analysis . A dust hazard analysis is led by a qualified person and involves analyzing the layout of the facility and its equipment, identifying dust sources and characterizing dust, determining how dust moves and accumulates throughout the facility, and finds possible sources of ignition like hot surfaces or electric sparks. A complete dust hazard analysis will show how much of a risk combustible dust is and highlight areas to improve. One effective upgrade would be adding isolation devices to dust collectors and duct work. These are large valves that keep different parts of the plant separated, reducing the chances of a dust ignition spreading through the entire facility. However, having ducts that are 24 to 36 inches in