As dry as dust? Not a chance! – What you should know about quartz dust
Interview with our colleague Johannes Sieger, Environmental Manager at Quarzwerke.
Mr. Sieger, you have been with Quarzwerke since November 2025, where you are responsible for industrial environmental protection and association work. What exactly does industrial environmental protection entail?
Environmental protection is fundamentally concerned with safeguarding water, soil, nature, the climate, and air. Building on this foundation, corporate environmental protection encompasses all measures aimed at minimizing the environmental impact of our facilities, conserving resources, and complying with legal requirements, such as those under environmental protection law.
As part of the “Legal/Environmental/Communications” (RUK) department, I advise and support our sites on a wide range of issues related to industrial environmental protection. Typical questions include: What emission limits apply to our drying systems or combined heat and power plants? What must be considered when disposing of waste? What requirements must washing stations, on-site fueling stations, and chemical storage facilities meet? What must be considered in permit procedures for facilities requiring approval under the Federal Immission Control Act? What new legal requirements must we comply with, and how do we implement them?
Fine quartz dust is a specific and sensitive issue within my area of responsibility. The topic is complex, is constantly being addressed by the scientific community and regulatory bodies, and affects us particularly in the areas of occupational safety, environmental protection, and chemical regulations. The latter governs, among other things, how we must correctly classify, label, and package our products in order to comply with the law.
What exactly is dust? And what’s the deal with particle size?
We encounter dust virtually everywhere—at home, outdoors in the environment, in cities, and, of course, in industrial facilities. It consists of finely dispersed solid particles suspended in the air. These particles can come from various sources: natural materials such as sand or soil, caused by wind erosion or volcanic activity; mechanical processes such as grinding or milling; air movement; road traffic abrasion; or they may appear in the form of pollen or dander.
At some workstations in our facilities, process-related dust is generated; this is referred to as Class A dust and can penetrate as far as the alveoli. The particles in the Class A dust fraction have a diameter of less than 10 µm. By way of comparison, a human hair has a diameter of approximately 100 µm.
Quartz fine dust refers to the portion of A-dust that consists of quartz. In Germany, an “assessment threshold1” of 0.05 mg/m³ applies to activities where quartz fine dust may be present. To put this value into perspective: If you were to extrapolate it to the air volume inside Cologne Cathedral, the total amount of dust contained therein would be around 20 grams, which is equivalent to the weight of about seven sugar cubes.
What health effects can result from inhaling fine quartz dust?
First of all, it’s important to realize that we all breathe in dust throughout our lives—all over the world. Our body’s natural defense mechanisms—such as nasal hairs, mucous membranes, and cilia—as well as our immune system are generally very effective at protecting us from dust. So not all dust is automatically harmful to our health. However, fine quartz dust can reach the deeper parts of the lungs and must therefore be considered separately.
Quartz dust poses a health risk only if large amounts are inhaled in the workplace over a long period of time. If exposure to this dust is brief and infrequent, it does not pose a health risk.
However, if a person is exposed to fine quartz dust at levels exceeding the applicable exposure limit2 over a long period of time—that is, every workday for several decades—there is an increased risk of developing silicosis, a dust-related lung disease that causes permanent lung damage. This link between fine quartz dust and silicosis has been scientifically proven for decades. That is why our industry—and quartz plants—have relied on technical, organizational, behavioral, and personal protective measures since the 1930s, which have been continuously refined with new technical advancements.
Where exactly does fine quartz dust occur, and how can we specifically protect our employees?
In our facilities, fine quartz dust occurs in relevant concentrations at only a few workstations due to the nature of the process, for example in the mills and during bagging. In the raw sand from open-pit mining, however, the proportion of quartz in the tiny particle size described above is extremely low. Furthermore, the raw sand produces hardly any dust due to its natural moisture content. Even in strong winds, therefore, there is no hazard posed by the sand in our mines.
To protect our workforce, we rely on a set of measures based on the STOP principle. This principle establishes a fixed hierarchy of occupational safety measures designed to minimize hazards. STOP stands for substitution, technical controls, organizational controls, and personal protective equipment.
Technically, this means that affected equipment is enclosed in dust-tight enclosures wherever possible. High-performance exhaust systems draw air through filter systems that remove the dust. Control rooms have a separate, independent fresh air supply and are maintained at a slight positive pressure. This prevents dust from entering even when someone enters the control room.
Many facilities, such as the one in Frechen, are also equipped with vacuum line systems. Special vacuum attachments can be connected to these lines, allowing for targeted cleaning of floors and equipment areas. This prevents dust from accumulating or becoming airborne. Using a broom would be counterproductive, as it would simply spread the dust and send it back into the air.
Organizational protective measures at the quartz plants include regular training sessions, briefings, and site inspections, as well as the provision of information. Personal protective measures include, most recently, the wearing of FFP3 masks at certain workstations.
We have accredited specialist firms conduct regular workplace measurements at all relevant workstations. If the threshold limit3 is exceeded, we respond immediately: we analyze the cause, determine appropriate measures, implement them, and then verify their effectiveness through follow-up measurements.
What else is particularly important to know when discussing fine quartz dust?
It is particularly important to assess the issue of fine quartz dust objectively. Levels of fine quartz dust that pose a health risk occur exclusively at specific workstations within our plants. There is no risk to employees at other workstations or to local residents—not even under specific weather conditions, such as strong winds.
At the same time, it’s important to stay mindful of this issue in your personal life as well. This applies especially to the passionate DIY enthusiasts among us. That’s because fine quartz dust can be released even during activities such as drilling, sanding, sawing, or transferring and mixing dry, quartz-containing materials. Simple but effective measures can help here: extraction directly at the source (e.g., with a vacuum cleaner), good ventilation of the workspace, moistening the work surface, and wearing an FFP3 mask.
Thank you very much for the fascinating interview.
- Under German law, so-called “assessment criteria” must be applied when there is no substance-specific occupational exposure limit (OEL) for a given substance (in this case, fine quartz dust). While an OEL is legally binding, an assessment criterion is used to determine whether the protective measures taken are sufficient. ↩︎
- See footnote 1 ↩︎
- See footnote 1 ↩︎
