Map every release point from product intake to cleaning.
A clean-looking filling head does not prove that the process controls dust. The largest release may occur when a bag is tipped into the hopper, when a vacuum receiver vents, when a screw feeder discharges, when the pack is moved before the powder settles or when operators clean the machine at the end of the batch.
| Process step | Typical release mechanism | Questions for the specification |
|---|---|---|
| Product transfer | Open tipping, displaced air, leaking connections or filter discharge. | Can transfer be enclosed? How is the container connected, emptied and removed? Where does displaced air go? |
| Hopper charging and refill | Falling product, agitation, venting and overfilling. | Is the refill manual or automatic? What level range is normal? Can capture remain effective during refill? |
| Dosing and cut-off | Free fall, nozzle dribble, displaced pack air and product entrainment. | What fill height and nozzle arrangement are used? Is the pack opening large enough for contained discharge? |
| Settling and closing | Air expelled from an aerated fill, vibration or rapid pack movement. | How long is available before capping or sealing? Can dust reach threads, rims or the heat-seal area? |
| Rejects and spillage | Manual emptying, damaged packs and rework. | How will rejects be isolated and emptied without creating a secondary exposure? |
| Cleaning and changeover | Brushing, compressed air, filter handling or dry product removal. | What approved method follows the site risk assessment, and how is collected dust contained and disposed of? |
Reduce release first, then design enclosure and capture at source.
Where practical, reduce manual transfer, shorten the free-fall distance, keep connections closed and avoid sudden discharge that entrains air. Partial or full enclosure can make local exhaust ventilation more effective, but the enclosure must still allow safe operation, cleaning and changeover. Capture should be placed close enough to the release without pulling saleable product out of the dose or disrupting a weigh signal, film path or heat-seal process.
Do not select an extraction fan or duct size from a generic machine photograph. The product, release rate, enclosure, duct run, filter, make-up air, discharge arrangement and assessed fire or explosion properties all affect the engineered system. Commissioning should verify containment at normal running, refill, stop, cleaning and the least favourable pack position.
- Record all manual interventions and occasions when a guard or enclosure is open.
- Confirm whether filters, hoses and collection vessels are compatible with the assessed material.
- Prevent settled dust from accumulating on ledges, electrical equipment and inaccessible parts of the line.
- Define safe waste handling and the route for recovered or rejected product.
- Include routine inspection, filter condition and extraction verification in maintenance instructions.
Keep dust control compatible with the finished pack.
For bottles, jars and tubs, the rim, thread and any induction-seal surface should remain clean enough for the closure process. A nozzle that sits too high may increase airborne product; a nozzle that enters the pack may improve containment but requires adequate opening, height control and collision protection.
For pouches and VFFS bags, product must clear the sealing zone before the seal jaws close. The dosing system, bag length, product settling, film movement, extraction and sealing dwell are one process. Excessive extraction can disturb a light pouch or remove product, while insufficient control can leave contamination in the seal.
Use current product data and a competent COSHH and DSEAR assessment.
Dust can present health risks, and some powders can create fire or explosion hazards when dispersed in air. The product's current safety data, process conditions and representative material testing should be reviewed by competent persons. The HSE explains the employer's duties under COSHH and DSEAR. HSE guidance on combustible dusts notes the importance of representative material data rather than generic assumptions.
This guide does not classify an area, determine whether a powder is explosive or specify protective equipment. Those decisions require the site-specific assessment, material test data and an engineered design appropriate to the process.
Prove containment in the real operating states.
Observe product transfer, normal filling, hopper refill, routine stop, pack change and cleaning. Record visible release, operator position, enclosure state, extraction indication, filter condition and any effect on dose or seal quality. If air monitoring, LEV examination or explosive-dust testing is required, use the competent service and test method specified by the site's assessment.
Containment is a line acceptance criterion.
A machine should not be accepted on fill weight alone when dust release, seal contamination or unsafe cleaning remains unresolved.