Fine powders in chemical processing disperse easily, contaminate batches and present respiratory and, in some cases, explosion risks. Effective control depends on contained transfer, high-efficiency filtration and strict housekeeping that prevents re-suspension.

Contain transfer and dispensing

• Use closed charging where possible (lined IBCs, rigid-bin docking). For bags, adopt safe opening: wet-wipe the exterior, slit low inside a capture hood and fold empty sacks before bagging out.
• Install weigh or downflow booths for manual dosing. Keep operators inside the capture zone and verify face velocities with simple smoke tests.
• Minimise drop heights and use slow feed screws to reduce kinetic release.

Capture and control the air

• Specify LEV based on under-load airflow. Ensure make-up air is clean and steady to avoid reflux out of hoods.
• Select HEPA appropriate to hazard; H14 is recommended for respirable and carcinogenic dusts. Position exhaust to avoid short-circuiting clean areas.
• Use negative air machines during cleaning and maintenance. Check pressure differentials across rooms where product integrity matters.

Housekeeping that prevents re-agitation

• Ban sweeping and compressed air. Use industrial vacuums with conductive hoses and antistatic accessories to manage static and fine PM1–PM2.5.
• Clean top-down, then verify with a white-glove or tape test. Short, frequent cleans outperform infrequent, deep cleans.

Procedures, monitoring and compliance

• Write simple SOPs for bag change, spill response and filter change-out with double-bagging to limit handling.
• Use a particulate monitor to trend background levels and trigger maintenance before product quality drifts.
• Under COSHH, control exposures to WELs per HSE EH40; apply hierarchy of control and confirm RPE suitability where required.

Practical takeaways

• Prefer closed transfer and weigh/downflow booths for manual dosing.
• Verify LEV capture and maintain H14 filtration where hazards demand it.
• Vacuum with conductive systems; avoid sweeping at all times.
• Set trigger levels using PM data to guide maintenance and cleaning.
• Keep SOPs short, trained and visible at the point of use.

By containing transfer, tuning LEV and maintaining disciplined housekeeping, fine powder lines stay cleaner, safer and more consistent.