You follow a strict cleaning regimen to keep your cleanrooms up to ISO standards. You have procedures in place to mitigate the hazards associated with flammable solvents. And you labor tirelessly to prevent cross-contamination to keep your products pure and your workers safe.
But are you overlooking the risk of combustible dust? If you manufacture oral solid dosage drugs, your plant is likely full of a variety of bulk powders. Many of these powders are combustible, and if they’re allowed to accumulate, they can provide fuel for a devastating explosion. For example, cellulose, a commonly used excipient, is considered by OSHA to be a strong explosion risk.
Solid dosage manufacturers aren’t alone. Many companies that supply the pharmaceutical industry are also at risk. In the highest-profile example, the West Pharmaceutical Services plant in North Carolina exploded in 2003, killing six people and causing dozens of injuries. The culprit was a fine plastic powder, used in the manufacture of medical products, that had been allowed to accumulate on ceiling tiles, light fixtures, and overhead beams.
Let’s look at how you can identify any dust hazards present in your facility and then prevent them from causing an explosion.
Dust testing and dust hazard analysis
Anywhere dust exists in a plant, there’s a possibility it might be combustible. In pharmaceutical manufacturing, dust can exist in many areas of operation — conveying, mixing, pouring, and so on. These areas are also prone to electrostatic discharge, which is the most common cause of ignition.
The only way to find out whether your dust is combustible is to have it tested.
Dust testing by a qualified laboratory is required under NFPA 652 for any facilities that generate, handle, or store dust. The test will evaluate several factors, including the dust cloud explosibility parameters and minimum ignition energy, to see if your dust is combustible. If it is, you’ll need to perform a dust hazard analysis (DHA) to determine whether the areas are deemed classified.
Learn more about the DHA and download a list of companies qualified to perform one here.
Housekeeping to prevent combustible dust explosions
There’s some good news in all of this: although combustible dust is prevalent in pharmaceutical plants, combustible dust incidents are 100% preventable. The secret is simply to not let the dust accumulate to hazardous levels — without fuel, you can’t start a fire.
Section 8.4 of NFPA 652 provides housekeeping guidelines for removing combustible dust from your facility. The top recommended approach is to vacuum using a vacuum cleaner listed for the purpose and location — either hazardous or nonhazardous.
Because electrostatic discharge is the most common ignition source in pharmaceutical manufacturing, we recommend ensuring all equipment used in areas containing combustible dust be bonded and grounded, and the accessories be conductive or static dissipative.
Vacuums used in pharmaceutical environments must also meet other requirements to keep products safe, pure, and effective. View our top 10 vacuum solutions for the pharmaceutical industry.
More than 100 people have been killed by combustible dust explosions at pharmaceutical plants. If you’ve been overlooking this risk, it’s time to start taking it seriously. Visit our page on pharmaceutical vacuums to learn more.