Are Quartz Countertops Radioactive?

Quartz countertops have become an extremely popular option for kitchen and bathroom remodels in recent years. Made from ground natural quartz crystals and polymer resins, these countertops are valued for their aesthetic appeal, durability, and low maintenance. However, some consumers have raised concerns about potential radiation emissions from quartz counters. So, are quartz countertops actually radioactive?

What Gives Granite and Quartz Countertops Radiation

Granite and quartz countertops contain trace amounts of naturally occurring radioactive elements like uranium, thorium, and radium. These elements are found in the Earth’s crust and are therefore present in stone materials like granite and quartz.

During the formation of natural stone, small amounts of these radioactive elements can get concentrated in the final material. Granite, which is an igneous rock, typically contains higher levels of radioactive elements than quartz, which is a metamorphic rock.

The main radioactive elements that can be found in granite and quartz countertops are:

  • Uranium – Uranium isotopes like Uranium-238 and Uranium-235 decay radioactively over time. Uranium is found in concentrations of 1 ppm to 100 ppm in granite.
  • Thorium – Thorium-232 is another radioactive isotope commonly found in granite. Thorium concentrations are generally around 1 to 10 ppm.
  • Radium – Radium isotopes like Radium-226 form as part of the decay chain of radioactive elements like uranium and thorium. Granite can contain 2 ppm to 20 ppm of radium.
  • Potassium-40 – A radioactive isotope of potassium found in natural stone. Potassium-40 makes up a small percentage of the total potassium.

So in summary, natural radioactivity in countertops comes from trace concentrations of these uranium, thorium, radium and potassium isotopes. Quartz has less radioactivity than granite since it contains fewer impurities.

Are Quartz Countertops Radioactive?

Quartz used for countertops is ground up from natural quartz crystals. Since quartz is a metamorphic rock, it has lower concentrations of radioactive elements than igneous rocks like granite.

Various scientific studies have analyzed the radiation levels of quartz countertops:

  • A study by the Illinois Emergency Management Agency found radiation emissions from quartz countertops were generally equivalent to background radiation levels.
  • Researchers at Rice University analyzed 55 samples of quartz surface materials and found radiation levels were largely at or near background levels, with an average surface radiation level of just 0.07 ± 0.04 microSieverts per hour.
  • The EPA states that based on limited preliminary data, radiation emissions from quartz are generally within a normal range of variation for natural background radiation.

So while quartz countertops do contain trace amounts of radioactive elements, the levels are very low and not much higher than ordinary background radiation. The small amounts of radiation they emit are generally considered safe and not a significant health hazard.

Are Quartz Countertops Safe?

Based on current scientific evidence, quartz countertops pose very little radiation risk and are considered safe for household use. Here are some key reasons why:

  • Low radiation levels – As discussed above, studies show radiation emissions from quartz are generally negligible and comparable to background radiation. The small amounts of radiation are well below any concerning safety thresholds.
  • Minimal direct exposure – Any radiation primarily comes from the stone itself. Since countertops are solid, radiation emitted is drastically reduced. This limits direct radiation exposure.
  • FDA approval – Materials used in quartz countertop fabrication have been approved for safety by the FDA for food contact and preparation. This suggests minimal chemical or radiation risks.
  • Routine testing – Leading quartz brands test for radioactivity during manufacturing. Brands like Caesarstone and Cambria ensure their slabs meet health and safety standards.
  • No increase in risk – Having quartz countertops does not significantly raise the risk of health problems like cancer. No studies have definitively linked quartz counters to increased illness rates.

So while nothing is completely risk-free, quartz countertops do not appear to pose any measurable health dangers from radiation under normal everyday use and are considered safe by health experts.

Do Quartz Countertops Emit Radon?

Radon is a radioactive gas that arises from the decay of radium, which can be found in trace amounts in natural stone. Granite countertops have sometimes raised concerns about radon emissions. However, quartz countertops have very low radon emissions for the following reasons:

  • Low radium content – Quartz has very low concentrations of radium, the source element for radon. Studies show quartz emits over 10 times less radon than granite.
  • Ventilation – Any radon emissions disperse rapidly with proper kitchen and bathroom ventilation. Normal air currents dilute radon.
  • Solid surface – Radon forms within stone but has difficulty escaping from the solid quartz surface, limiting emissions.
  • No conclusive risk – No studies have clearly attributed indoor radon exposure to increased cancer rates from quartz countertops. Estimated risks are negligible.

While quartz can emit trace amounts of radon, the amounts are minimal and not considered dangerous or above background levels. Proper ventilation is recommended as an additional precaution to dilute any radon. Overall, radon exposure from quartz countertops is generally considered insignificant.

How to Measure Radiation from Quartz Countertops

To measure any radiation emissions from quartz countertops, homeowners can use a radiation detector. Two main types of detectors can be used:

  • Geiger counter – This device detects ionizing radiation and can measure alpha, beta, and gamma radiation exposure in counts per minute. Models designed for consumers typically cost $50 to $100.
  • Dosimeter – This measures accumulated radiation dose over longer periods. Simple cheap dosimeters like radiochromic film can estimate dosage. More expensive electronic dosimeters are also available.

To test countertops, simply place the Geiger counter probe or dosimeter on the counter surface for a period of time, such as 24 hours. Background measurements should be taken further away from the counter for comparison.

The readings on quartz counters generally show only negligibly higher levels than background radiation. Geiger counters may pick up some minor fluctuations from trace uranium or thorium. But overall, radiation counts should be extremely low.

Are Some Quartz Countertops More Radioactive Than Others?

Since natural stone varies, some quartz slabs can have slightly higher radioactive content. Certain brands and colors tend to test higher.

According to Consumer Reports, these quartz products occasionally registered at moderately higher radiation levels:

  • Caesarstone – Certain colors like Strawberry Quartz and Raven.
  • Cambria – Some batches of the Summerhill and Roxwell colors.
  • Silestone – Very low radioactivity overall but the EA Report found the Helix color to be higher.

However, even in these occasionally higher cases, radiation exposure was still minimal and comparable to background levels. The increased radioactivity is generally trivial and not a significant concern. Still, anyone buying quartz may want to choose from batches with the lowest radioactive content.

Is Quartz More Radioactive Than Granite?

Quartz emits lower levels of radiation than granite countertops. Since granite is an igneous rock, it typically contains higher concentrations of uranium and thorium.

Specific comparisons include:

  • An EPA study found radiation emissions from granite counters were routinely over 10 times higher than measurements from quartz counters.
  • 511 granite samples analyzed for radioactivity had an average Ra-226 concentration of 32.8 Bq/kg, versus 4.9 Bq/kg for the 55 quartz samples tested at Rice University.
  • The Illinois study showed red and black granites registered radiation levels noticeably higher than backgrounds levels, while quartz counters did not.

So quartz emits less radiation than granite due to having lower uranium and thorium content. However, both countertop materials are still considered safe since their radiation levels are low.

Tips to Limit Radiation Exposure from Quartz Countertops

Here are some recommendations to minimize any radiation emissions from quartz counters:

  • Ventilate – Proper ventilation can dissipate any radon gas buildup. Use exhaust fans and open windows.
  • Limit direct contact – Cut down on prolonged direct contact with the countertop surface to reduce radiation exposure. Use cutting boards.
  • Apply sealant – Applying a sealant may help prevent radon from escaping through cracks or gaps in the quartz surface.
  • Test countertops – Screen countertops using a Geiger counter before installing to choose lower radiation batches.
  • Increase distance – Since radiation drops off with distance, placing seating further away from quartz surfaces can reduce exposure.
  • Clean regularly – Use damp microfiber cloths to wipe up any dust that may accumulate and contain loose radioactive particles from the stone.

However, the radiation risks are already so low that any extra measures are optional precautions and may only have a marginal effect. Just avoiding prolonged direct contact provides reasonable assurance of minimal exposure.

Are Recycled Quartz Countertops Radioactive?

Recycled quartz utilizes slag from industrial waste streams to supplement a portion of the natural quartz. This recycled material can theoretically introduce more impurities that increase radiation levels slightly.

However, most studies have found that recycled quartz is still well within safety limits:

  • A study in the Journal of Environmental Radioactivity tested slabs of recycled quartz from IceStone and PaperStone brands and found radiation emissions indistinguishable from background levels.
  • Researchers at the University of Akron tested over 150 slabs from Vetrazzo recycled glass and quartz surfaces and found radioactivity levels were safe and consistent with regular quartz products.
  • Recycled quartz brands Certify that their products meet health and safety standards for radiation.

Based on current testing, the amount of recycled content used does not appear to raise radiation levels significantly enough to pose any real health dangers. Consumers can have confidence that recycled quartz counters are safe.

Frequently Asked Questions

How much radiation is emitted from quartz countertops?

Typical quartz countertops emit radiation at background levels of around 0.01 to 0.1 microSieverts per hour, which is low. Higher background radiation comes from outer space, the air, and the ground. Studies show quartz radiation is well below safety limits.

Can quartz counters increase cancer risk?

There is no definitive evidence that quartz counters contribute to increased cancer risk. The extremely low radiation exposure is insignificant compared to other sources we encounter. Natural stone materials have been used safely for thousands of years.

Is radiation higher for white quartz?

No, the color is not a major factor. Trace radioactivity comes from minerals in the original stone before processing. However, some specific color patterns or batches may test slightly higher. Brands constantly test and monitor radiation levels across all their quartz colors.

Can you remove radiation from quartz?

Not easily. Removing uranium, thorium, and radium would involve reprocessing the raw quartz crystals. Manufacturers select quartz with the lowest radiation readings. Quartz on average contains less radium than granite.

Do more expensive quartz brands have less radioactivity?

Not necessarily. Natural variation means some budget quartz has less radioactivity than premium options. But many higher-end brands like Caesarstone rigorously screen all slabs to ensure low radiation. Paying more may provide extra peace of mind.

Does sealing quartz reduce radon gas emissions?

Sealants can help prevent radon exposure but are not always necessary. Since quartz emits such low amounts of radon in the first place, sealants provide only marginal improvement. Ensuring proper ventilation is more important to dilute radon.


In summary, quartz kitchen and bathroom countertops contain only trace levels of natural radioactivity emitted from uranium, thorium, and radium isotopes in the stone. However, extensive scientific testing has shown that any radiation exposure from quartz countertops is barely above normal background levels.

Leading health and regulatory organizations confirm that quartz countertops are completely safe for homes. Their emissions are well below all acceptable safety limits for radiation exposure. While a few quartz products can occasionally test moderately higher, the overall risks are still negligible. With proper general ventilation, quartz countertops pose no real radiation hazard and can be safely installed in kitchens and bathrooms.