Health & Safety · Stone Industry
Silica-Free Engineered Stone:
What It Is and Why It Matters
Traditional engineered quartz contains up to 93% crystalline silica — the primary occupational hazard in stone fabrication shops. Silica-free surfaces like PHI, Symphony, and QT Quartz eliminate this risk entirely. This guide explains what crystalline silica is, what it does, and why the fabrication industry is switching to silica-free alternatives.
Published by Urban Stone Source · Last updated: May 2026
Max silica in traditional quartz
by weight
Crystalline silica in PHI, Symphony & QT Quartz
independently certified
OSHA permissible exposure limit
8-hr time-weighted average
OSHA dust controls required
for silica-free fabrication
Section 1
What is crystalline silica?
Crystalline silica (silicon dioxide, SiO₂) is one of the most common mineral compounds on earth. It is found in sand, soil, granite, and most natural rock formations. In engineered quartz manufacturing, crystalline silica serves as the primary binding mineral — ground quartz particles are compressed with resin binders under high heat and pressure to form slabs.
Traditional engineered quartz surfaces contain between 70% and 93% crystalline silica by weight, depending on the manufacturer and product line. This is what gives standard quartz its hardness and scratch resistance.
The problem is not the silica in the finished slab — it is inert and poses no health risk in countertops used in the home. The hazard arises during fabrication: when slabs are cut, ground, drilled, and polished in a fabrication shop, the process generates fine respirable silica dust. This dust, at microscopic scale, penetrates deep into lung tissue where the body cannot clear it.
Section 2
What is silicosis — and who is at risk?
Silicosis is an occupational lung disease caused by inhaling respirable crystalline silica dust over time. It is irreversible, progressive, and potentially fatal. There is no cure — treatment is supportive and aimed at slowing progression.
Chronic Silicosis
10+ years of moderate exposure
The most common form. Gradual scarring of lung tissue. Symptoms may not appear until decades after first exposure.
Accelerated Silicosis
5–10 years of higher exposure
Faster progression of fibrosis. Workers in dry-cutting environments face this form.
Acute Silicosis
Weeks to 5 years of very high exposure
Rapid, severe lung inflammation. Can be fatal within months of diagnosis. Associated with powered dry cutting of artificial stone.
Stone fabricators — workers who cut, grind, and finish countertops — face the highest occupational silica exposure risk of any trade. A 2019 study in the American Journal of Respiratory and Critical Care Medicine documented an emerging epidemic of accelerated silicosis among engineered stone countertop fabricators, particularly those using dry-cutting methods without adequate dust controls.
Silicosis also elevates risk for lung cancer (IARC Group 1 carcinogen classification for inhaled crystalline silica) and COPD. Fabricators with silicosis have significantly reduced life expectancy and quality of life.
Section 3
OSHA silica regulations for stone fabrication
The U.S. Occupational Safety and Health Administration (OSHA) enforces two standards that apply to stone fabrication:
29 CFR 1910.1053 (General Industry)
Permissible Exposure Limit (PEL): 50 µg/m³ as an 8-hour time-weighted average
Action Level: 25 µg/m³ — triggers medical surveillance requirements
29 CFR 1926.1153 (Construction)
Same 50 µg/m³ PEL. Applies when fabrication work is classified as construction activity.
To comply with the silica standard, fabrication shops must implement a hierarchy of controls:
Engineering Controls
- —Wet cutting methods
- —Local exhaust ventilation (LEV)
- —Enclosed cutting systems
- —HEPA vacuum attachments
Administrative Controls
- —Exposure assessments and monitoring
- —Written Exposure Control Plan
- —Designated regulated areas
- —Worker training programs
Medical Surveillance
- —Baseline lung function testing
- —Periodic follow-up assessments
- —Physician review of exposure records
- —Employee notification protocols
Respiratory Protection
- —Respirator program (29 CFR 1910.134)
- —Fit testing for workers
- —Respirator maintenance
- —Training and recordkeeping
These compliance requirements represent significant ongoing costs for fabrication shops — in equipment, labor, testing, and program administration. Shops that switch to certified silica-free stone materials eliminate these requirements for the portions of their work using silica-free slabs.
Section 4
Silica-free vs. traditional quartz: side by side
Section 5
Certified silica-free stone available in Georgia, Alabama & Tennessee
Urban Stone Source is the exclusive Southeast distributor of three certified silica-free engineered stone collections. All are independently tested and verified at 0% crystalline silica.
PHI by Aurea Stone
- ·0% crystalline silica — certified
- ·4R+ Fullbody technology
- ·12 colors, 3cm, 126×63 in
- ·Up to 100% recycled content
- ·Lifetime NEOS anti-stain warranty
Symphony by Aurea Stone
- ·0% crystalline silica — certified
- ·EPD certified
- ·9 colors, 2cm & 3cm, 126×63 in
- ·Up to 90% recycled content
- ·EcoPress zero-water-waste manufacturing
QT Quartz
- ·0% crystalline silica — certified
- ·Super Jumbo: 139×79 in slabs
- ·13 colors, 3cm polished
- ·Fewer seams on large installations
- ·Ideal for commercial & hospitality
Frequently Asked Questions
Silica-free stone — common questions
Does silica-free stone perform the same as traditional quartz?
Yes. PHI by Aurea Stone, Symphony by Aurea Stone, and QT Quartz meet the same performance standards as traditional quartz for countertop and surface applications. They are non-porous, scratch-resistant, and stain-resistant — PHI and Symphony include lifetime NEOS anti-stain warranties. Eliminating crystalline silica does not reduce hardness, durability, or surface performance.
Is silica-free stone more expensive than traditional quartz?
Silica-free engineered stone is priced in the premium segment, comparable to high-end traditional quartz. However, fabrication shops should factor in the total cost of ownership: eliminating OSHA silica compliance costs (dust control equipment, medical surveillance programs, exposure monitoring, respiratory protection) reduces overhead. For shops doing significant volume, the savings on compliance can offset the premium material cost.
Where can I buy silica-free engineered stone in the Southeast?
Urban Stone Source is the exclusive Southeast distributor of PHI by Aurea Stone, Symphony by Aurea Stone, and QT Quartz. We serve Georgia, Alabama, and Tennessee. Our showroom is at 6670 Jones Mill Court, Suite E, Peachtree Corners, GA 30092. Call (336) 407-9167 or email sales@urbanstonesource.net.
What does 'independently certified 0% crystalline silica' mean?
It means the material has been submitted to an accredited third-party laboratory for chemical analysis, and the test results confirm no detectable crystalline silica content. This is distinct from a manufacturer's claim — independent certification involves testing by a lab with no financial relationship to the manufacturer. PHI, Symphony, and QT Quartz hold independent certifications.
Georgia · Alabama · Tennessee
The Southeast's exclusive source
for silica-free engineered stone
PHI, Symphony, and QT Quartz — all certified 0% crystalline silica — available exclusively through Urban Stone Source. Call (336) 407-9167 or request samples shipped to your Georgia, Alabama, or Tennessee location.