Dust extraction for vitamin additives

What is vitamin additive dust?

Weighing, mixing and packing micro-ingredients for animal feed releases a lot of dust. This involves tiny quantities of vitamins, trace elements, amino acids and enzymes. These substances rarely become airborne in their pure form. Vitamins are almost always supplied on a carrier - such as wheat middlings or limestone flour - so they can be dosed evenly. This blend is known as a premix. What becomes airborne is therefore always a combination of the active substance and the carrier, and it is precisely that ratio that determines how the dust behaves. The properties of the material also play a major role: some ingredients absorb moisture and clump, while others cling to everything thanks to a coating of oil or fat.

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Why this dust differs from bulk dust

With grain or flour, the problem lies in the large quantity. Here it is precisely the small quantity that makes it dangerous. The biggest risk is carry-over: dust transferring unnoticed into a following batch. Because a micro-ingredient is added in minuscule amounts, even a tiny trace of residual dust can already ruin an entire new batch. That applies all the more to medicated feed or substances with a strict statutory limit. Dust that lingers in the room and settles on scales, bags or clothing is the main culprit here. A good extraction system therefore protects two things at once: your employees' health and your product's quality. The difficult part is that this dust does not capture easily. Moisture-absorbing substances clump inside the filter, greasy particles stick to the walls, and the tiniest carrier particles fly straight through everywhere. An extraction system has to handle all these different properties at once, because in a premix operation these substances are all mixed together.

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Where this dust is released

Exposure to this dust concentrates on a handful of specific points. It is precisely at those points that handling is often still open:

• The weighing room: Weighing by hand from bags and drums happens close to the face. This typically produces the highest dust concentration in the entire facility.
• Emptying bags: Tipping bags into mixers and storage bins.
• The mixing process: Dust released while filling and discharging the mixers.
• Conveying and transfer: Dusty points at pneumatic conveying lines and transfer points.
• Filling and packing: Bagging and packing the finished premix.
• Cleaning and formula changeover: Dust released when cleaning the rooms or switching formulas.

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Health risks

The risk follows the composition, which differs by formula. Two routes recur consistently.

• ‍Irritation of the airways, eyes and skin. Fine powder is mechanically irritating regardless of content. With open handling in a weighing room, concentrations can rise quickly.‍
• Sensitisation. Certain enzymes and additives can trigger a lasting allergy, resulting in occupational asthma. Once sensitised, a person reacts to very low concentrations thereafter.

Exactly which risks apply to your raw materials is set out in your supplier's safety data sheet. That is the starting point, not the product name on the bag.

What extraction achieves here

Respiratory protection only works while it is worn and correctly fitted, and in a weighing room it gets in the way of every action. Capture at source works for everyone in the space, including the colleague who is only fetching a bag. That is also the order of control the EU Chemical Agents Directive requires.

And the effect goes beyond health: less dust in the room means less carry-over and fewer rejected batches.

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Fire and explosion risk

This dust is organic and combustible. Finely dispersed in air it forms an explosive mixture; most premix dusts fall into dust explosion class St 1, though the characteristic values differ by formula and carrier. Two points are specific here. Fat-coated components can accumulate in filters and ductwork into a layer that smoulders rather than burns off. And because formulas change, the characteristic values change with them - an installation sized for one blend is not automatically sized for the next. The ATEX directives 2014/34/EU and 1999/92/EC apply, with zone classification and an explosion protection document.

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Legislation and standards

The EU Chemical Agents Directive requires employers to assess exposure and reduce it as far as possible, with engineering controls at source taking priority over personal protective equipment. For sensitising components, exposure must additionally be reduced as far as is reasonably practicable, even below the limit value. The exposure assessment follows EN 689, and specific limit values are set nationally, so check what applies where you operate.

Alongside that, the finished product falls under EU feed legislation and the quality schemes built on it, such as GMP+ and FAMI-QS - the latter specifically for premixtures and feed additives. These set requirements for carry-over and cleaning between formulas. A well-designed extraction system is one of the measures that makes that demonstrable.

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Sectors where this dust plays a role

• Vitamin and feed additive manufacturers
• Premix operations
• Compound feed production
• Pet food manufacturing
• Aquafeed and specialty feed

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How do you extract this dust effectively?

The approach centres on the points where handling is open, and on preventing dust from carrying over between formulas.

• ‍Extraction at the weighing point. An extracted weighing table or booth captures the dust the moment the bag is opened. This is the point of highest exposure and the greatest carry-over risk - it is where extraction starts.‍
• Source capture at tipping and transfer points, so dust does not enter the room during filling and discharging.‍
• Pre-separation ahead of the main filter, so coarser carrier particles do not clog the fine filter.‍
• Filtration matched to sticky and clumping dust. With hygroscopic and fat-coated components, the filter medium and cleaning settings need particular attention.‍
• Cleanability as a design requirement. Smooth surfaces, minimal dead spots and good access determine how quickly and completely you can clean between formulas.‍
• ATEX construction matched to the classified zone, with earthing and spark detection where required.

Our engineers map out per situation which components are processed, where handling is open and how often the formula changes. Capacity, filter choice and construction follow from that.

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Dust control for vitamin additives by Kiekens

With over 100 years of experience in industrial dust extraction, we build installations for producers of vitamins, premixes, and feed additives, from weighing booths to central dust collection. We start by observing: where are the bags opened, how often do you change recipes, and what sticks to your filter? Then we design, build, and maintain everything under one roof. With the Clean Air Plan, we keep your installation in top condition all year round.

Would you like to know how much dust is released at your weighing and dosing stations? Request a no-obligation baseline measurement from one of our specialists.