Silica is one of the most common minerals on Earth. Found naturally in sand, stone, concrete, brick, and glass, silica is an essential building block of modern infrastructure. Yet when silica becomes airborne, it can pose serious and long-lasting health risks.
Understanding what silica is, why it matters, and how it is monitored is essential not only for industry professionals, but for anyone who lives, works, or spends time around construction, renovation, or industrial activity.
WHAT EXACTLY IS SILICA?
Silica, or silicon dioxide (SiO₂), is a naturally occurring compound made of silicon and oxygen. It exists in several forms, but from a health perspective, the most important distinction is between:
- Amorphous silica – generally considered less harmful
- Crystalline silica – the primary health concern
Crystalline silica is present in materials such as:
- Sand
- Granite
- Quartz
- Concrete
- Masonry products
On its own, silica-containing materials are not dangerous. The risk arises when these materials are cut, drilled, ground, crushed, or disturbed, releasing tiny particles into the air.
WHY IS AIRBORNE SILICA DANGEROUS?
When silica-containing materials are disturbed, they can generate respirable crystalline silica — microscopic particles small enough to be inhaled deep into the lungs. These particles are so small that they are invisible to the naked eye and can remain suspended in the air long after work has stopped.
WHY CAN’T YOU RELY ON SIGHT OR SMELL
One of the most challenging aspects of silica exposure is that it cannot be reliably detected without specialized equipment.
- Silica dust is odorless
- It may not be visible, even when concentrations are high
- “Clean-looking” environments can still pose risks
Because of this, monitoring silica exposure requires quantitative air sampling, rather than visual assessment.
HOW IS SILICA EXPOSURE MEASURED?
Silica is measured using air monitoring equipment designed to capture airborne particles over time.
A typical silica air monitoring setup includes:
- A calibrated air sampling pump
- A flow control device that regulates air intake (measured in liters per minute)
- A filter cassette that collects airborne dust
- A stable mounting system, such as a tripod, to ensure accurate sampling
The pump pulls air through the filter at a controlled rate for a specific duration. The collected dust is then sent to a laboratory, where analysts determine:
- The total dust concentration
- The amount of respirable crystalline silica present
This process allows professionals to assess exposure levels and compare them to occupational or environmental safety standards.
WHO IS AT RISK OF SILICA EXPOSURE?
Silica exposure is most commonly associated with certain industries and activities, including:
- Construction and demolition
- Mining and quarrying
- Stone fabrication
- Concrete cutting and drilling
- Roadwork and infrastructure projects
- Manufacturing of glass, ceramics, and bricks
However, silica exposure is not limited to workers alone. Occupants of buildings undergoing renovation, nearby residents, and even bystanders can be affected if dust controls are not properly implemented.
WHY MONITORING MATTERS
Air monitoring plays a critical role in silica risk management. It helps to:
- Identify whether silica is present in the air
- Quantify exposure levels
- Evaluate the effectiveness of control measures
- Ensure compliance with occupational and environmental regulations
- Inform decisions about ventilation, dust suppression, and protective equipment
Without monitoring, exposure can go unnoticed — sometimes until irreversible harm has already occurred.
BOTTOM LINE
Silica is everywhere, but harmful exposure is preventable. Understanding when silica becomes dangerous and how it is measured empowers both professionals and the public to make safer choices.
Whether it’s a construction site, a renovation project, or an industrial operation, monitoring the air is one of the most reliable ways to protect health. Silica may be invisible, but with the right tools and knowledge, its risks don’t have to be.