When combustible materials are in a finely divided dust form, they can burn rapidly. If the dust is suspended in the air in the right concentration, under certain conditions, it can become explosible. Even materials that do not normally burn in larger solid amounts (such as aluminum or iron), given the ideal conditions, can be explosible when they are in dust form.
These materials are becoming prevalent with the increase in metal 3d printing, but even noncombustible stable dusts should be treated the same. As always, good hygiene can help prevent accidents:
Regularly clean areas that may accumumlate dust such as lateral surfaces and corners
Prevent dust accumulation by taking care when sifting and pouring powders, not agitiating the material more than necessary
Use wet methods to remove dust such as a wet sponge or paper towel
Vaccuum cleaners may concentrate combustible powders and a spark may be provided by the motor so ensure any vaccuum is rated for powder applications
Incident Spotlight-Imperial Sugar Company Dust Explosion and Fire
On February 7, 2008, a huge explosion and fire occurred at the Imperial Sugar refinery northwest of Savannah, Georgia, causing 14 deaths and injuring 38 others, including 14 with serious and life-threatening burns. The explosion was fueled by massive accumulations of combustible sugar dust throughout the packaging building.
You can find more information about this incident on the Chemical Safety Boards website: https://www.csb.gov/imperial-sugar-company-dust-explosion-and-fire/
Silica Gel Safety
Silica gel is commonly used in chemistry labs. Silica gel consists mainly of silicon dioxide in a crystalline or non-crystalline form.
Non-crystalline (amorphous) silica is generally the main form used in chromotography. Amorphous silica does not present high flammability or health risk, but good hygiene and PPE guidelines must still be followed. Dust accumulation should be avoided on surfaces near the waste or fill stations, and inhalation should be avoided by using ventilation or PPE.
Respirable silica usually refers to crystalline silica created during cutting, sawing, and grinding stone or concrete. These materials present a much higher respiratory risk and are specifically covered in OSHA's Silica Standard.
Silica Waste
Silica gels and associated contaminated items are handled as hazardous waste through our hazardous waste program. Most labs store their waste in the blue HDPE drum that their gels had originally shipped in, which is perfectly fine. Be sure to label the drum as hazardous waste appropriately, and label all potential contaminants within the gel waste so we can be sure to dispose of it appropriately. If possible, we advise adding the gel to the waste container with ventilation whenever possible (Aircuity “snorkel” ventilation is commonly used), to prevent any potential inhalation hazards from this waste.
Holiday Safety Note
If you are tasked with carving up the turkey for thanksgiving or friendsgiving this month, remember the moniker:
"A falling knife has no handle!"
Attempting to catch a knife that has slipped from your grasp will most likely cause a serious cut or laceration, so step away and let the knife fall. Do you think this applies to your lab too?
