If you own vintage Fiestaware or recently inherited your grandmother’s colorful dish collection, you may have heard a startling claim: some Fiestaware is radioactive.
This isn’t an urban legend or internet myth; it’s actually true. Certain colors of vintage Fiesta dinnerware contain uranium oxide in their glazes, making them measurably radioactive with a Geiger counter.
Before you panic and box up your cherished dishes, here’s the reassuring news: the radiation levels from vintage Fiestaware are relatively low, and with proper precautions, these pieces can be safely displayed and even occasionally used.
The key is understanding which pieces contain uranium, how much radiation they emit, and what safety guidelines to follow.
This article separates fact from fiction about radioactive Fiestaware, explaining the science behind uranium glazes, which colors are affected, actual radiation levels compared to everyday sources, and practical safety recommendations.
Whether you’re a collector, inherited vintage pieces, or simply curious about this fascinating piece of American history, you’ll learn everything you need to know about Fiestaware’s radioactive properties and how to handle these pieces responsibly.
Is Fiestaware Radioactive?
Is Fiestaware radioactive? The direct answer is yes, but only certain vintage pieces made during specific time periods.
Vintage Fiesta dinnerware in red and ivory colors produced between 1936 and the early 1970s contains uranium oxide in the glaze, which makes them emit low levels of radiation.
However, this doesn’t mean you need to immediately dispose of these pieces or fear for your safety.
The radiation levels are relatively low, and for display purposes or occasional use, the health risks are minimal.
The primary concern arises with regular, daily use, especially when serving hot, acidic foods that can potentially leach small amounts of uranium from the glaze into food.
It’s crucial to understand that not all Fiestaware is radioactive. Most vintage Fiesta colors, including the popular cobalt blue, yellow, light green, and turquoise, contain no uranium whatsoever.
Additionally, all modern Fiesta dinnerware produced from 1986 onward is completely uranium-free and safe for everyday use without any concerns.
The radioactive vintage pieces are primarily limited to red Fiesta made before 1943 (and some pieces from 1959-1972) and ivory Fiesta from 1936-1951.
If your vintage Fiesta collection consists of other colors, you can use them without any radiation concerns.
The History of Uranium in Fiestaware
To understand why some Fiestaware contains uranium, we need to look back at the ceramics industry in the early 20th century.
Using uranium oxide in ceramic glazes was not unusual or considered particularly dangerous at the time; it was an accepted industry practice for achieving certain vibrant colors that were difficult to produce otherwise.
When Frederick Hurten Rhead designed Fiesta dinnerware for Homer Laughlin China Company in 1936, he wanted bold, eye-catching colors that would stand out in the marketplace.
The brilliant orange-red shade he achieved used uranium oxide, which created an exceptionally vibrant, stable color that didn’t fade over time.
This same uranium compound also contributed to the creamy richness of the ivory glaze.
Glass and Ceramic Production using Uranium Oxide
Uranium oxide had been used in glass and ceramic production since the 1830s, and by the 1930s, it was a well-established colorant in the pottery industry.
Many manufacturers beyond Homer Laughlin used uranium in their glazes, making radioactive dinnerware relatively common during this era.
The practice wasn’t considered controversial because the health risks of low-level radiation exposure weren’t fully understood or appreciated at the time.
The first interruption to uranium use in Fiesta came during World War II. In 1943, the U.S. government restricted civilian use of uranium because it was needed for the Manhattan Project and nuclear weapons development.
Homer Laughlin stopped producing red Fiesta entirely during the war years, and the color wasn’t reintroduced until 1959.
When red returned to the Fiesta lineup in 1959, it still contained uranium, though possibly in different concentrations than the original formula.
However, as awareness of radiation hazards grew throughout the 1960s and early 1970s, Homer Laughlin eventually reformulated their glazes.
By the time Fiesta production ended in 1973, and certainly when it was reintroduced in 1986, all uranium was removed from the glazes.
The ivory color, which also contained uranium oxide (though typically at lower levels than red), was discontinued in 1951 and never reintroduced, eliminating that source of radioactive Fiesta as well.
Which Fiestaware Colors Are Radioactive?
Not all vintage Fiestaware is radioactive; in fact, most colors contain no uranium whatsoever. Here’s a comprehensive breakdown of which pieces you should be concerned about:
Red Fiesta (Radioactive)
- Original red (1936-1943): This is the most radioactive Fiesta color. All red pieces from this period contain uranium oxide and will register on a Geiger counter. These are also the most sought-after by collectors.
- Reintroduced red (1959-1972): When red returned after World War II, it continued to use uranium oxide in the glaze, at least initially. Most red Fiestas from this period are also radioactive, though some later pieces may have reduced uranium content or none at all as formulations changed.
- Modern red (1986-present): Completely uranium-free and safe. These pieces look similar but use different glaze chemistry.
Ivory Fiesta (Radioactive)
- All ivory (1936-1951): Ivory Fiesta contains uranium oxide, though typically at lower concentrations than red pieces. All ivory pieces from this production period are radioactive, though they generally emit less radiation than red pieces.
All Other Vintage Colors (NOT Radioactive): The following vintage Fiesta colors contain no uranium and are completely safe:
- Cobalt blue
- Light green
- Yellow
- Turquoise
- Medium green
- Forest green
- Rose
- Chartreuse
- Gray
These colors use different mineral compounds and metal oxides to achieve their hues, none of which are radioactive.
Modern Fiesta (NOT Radioactive)
All Fiesta dinnerware produced from 1986 to the present day is uranium-free, regardless of color. This includes modern red, which achieves its color through alternative glaze formulations.
Identifying Radioactive Pieces: If you have a vintage red or ivory Fiesta, the backstamp can help you date the piece. Vintage pieces typically have “FIESTA HLC USA” impressed into the bottom.
However, the most reliable way to determine if a piece is radioactive is to test it with a Geiger counter or to have it professionally evaluated.
Other Pottery with Uranium Glazes: Fiesta wasn’t alone in using uranium.
Other brands like Harlequin (also by Homer Laughlin), certain patterns of Hall China, and various other American pottery companies produced radioactive orange, red, and yellow-glazed items during the same era.
Even some imported ceramics from Europe contained uranium glazes.
How Radioactive Is Fiestaware, Really?
When people hear “radioactive,” they often imagine dangerous levels of radiation that pose immediate health risks.
The reality with Fiestaware uranium is far less alarming when you understand the actual numbers and put them in perspective with other radiation sources we encounter regularly.
Measuring the Radiation
Radiation is measured in several units, but for our purposes, we’ll use microsieverts (µSv), which measure the biological effect of radiation exposure.
A standard Geiger counter can detect radiation from a vintage red Fiesta from several inches away, and the clicks become more frequent as you move the detector closer to the surface.
At the surface of a vintage red Fiesta plate, radiation levels typically measure between 5 to 10 microsieverts per hour (µSv/hr), though some pieces may be higher or lower depending on the uranium concentration in that particular batch of glaze.
Ivory pieces generally measure lower, often in the 1-3 µSv/hr range at the surface.
Putting It in Perspective
These numbers mean little without context, so let’s compare them to radiation sources you encounter in everyday life:
- Background radiation: Simply living on Earth, you’re exposed to about 0.1 to 0.3 µSv/hr from cosmic rays, radon gas, and naturally occurring radioactive materials in soil and rocks.
- Airplane flight: Flying at cruising altitude exposes you to about 2-3 µSv/hr due to cosmic radiation.
- Chest X-ray: A single chest X-ray delivers about 100 µSv of radiation in an instant.
- Eating a banana: Bananas contain potassium-40, a radioactive isotope. Eating one gives you about 0.1 µSv of radiation exposure (this is where the informal “banana equivalent dose” comes from).
- Living in a brick or stone house: These materials contain trace amounts of radioactive elements, adding about 0.05 µSv/hr to your exposure.
The Type of Radiation Matters
Not all radiation is equally dangerous. Uranium-238 and uranium-235 (the isotopes in Fiestaware) primarily emit alpha particles, along with smaller amounts of beta and gamma radiation.
Alpha particles are relatively large and can’t penetrate skin; they can be stopped by a sheet of paper or even the dead outer layer of your skin.
This means external exposure (just being near radioactive Fiesta) poses minimal risk.
The concern with uranium in dinnerware isn’t external exposure but rather internal exposure if uranium leaches into food and is ingested.
Once inside the body, alpha emitters can damage cells more directly. However, the amounts that could potentially leach from properly maintained Fiesta glazes are very small.
Distance Reduces Exposure Dramatically
Radiation follows the inverse square law, meaning it decreases rapidly with distance.
If you measure 10 µSv/hr at the surface of a plate, stepping just one foot away reduces your exposure to near background levels.
This is why displaying radioactive Fiesta on a shelf or in a cabinet poses virtually no health risk—you’re simply not close enough, long enough, for any significant exposure.
Scientific Studies and EPA Findings
The U.S. Environmental Protection Agency (EPA) and various health physics researchers have studied uranium-glazed ceramics.
Their consensus is that owning and displaying these items poses negligible health risks.
The primary recommendation is to avoid using them regularly for food service, particularly with acidic foods that could increase leaching.
One study found that leaching of uranium from properly glazed pieces into neutral liquids was minimal, but increased significantly with acidic foods and hot temperatures.
This is the basis for current safety recommendations.
Is It Safe to Use Radioactive Fiestaware?
This is the question most people want answered: Can you actually use vintage radioactive Fiestaware, or should it be relegated to display-only status?
The answer depends on how you intend to use it and your personal risk tolerance.
Display Use: Generally Safe
Displaying radioactive Fiesta on shelves, in cabinets, or as decorative pieces is considered safe by most health physicists.
The radiation exposure from having these items in your home is minimal, far less than many other sources of background radiation you’re exposed to daily.
As long as the pieces aren’t chipped or damaged, and you’re not handling them constantly, display poses virtually no health risk.
Occasional Use: Low Risk
Using vintage red or ivory Fiesta for special occasions a few times a year carries very low risk, especially if you follow some basic guidelines.
For occasional use with cold or room-temperature, non-acidic foods, the amount of uranium that could potentially leach into food is negligible.
Many collectors do use their vintage pieces occasionally without concern.
Regular Daily Use
Not Recommended: Health experts and collectors agree that using radioactive Fiestaware for everyday dining is not advisable.
While the risk from any single meal is small, cumulative exposure over months and years could potentially be concerning.
The uranium in the glaze is somewhat soluble and can slowly leach into food, particularly under certain conditions.
Foods and Conditions to Avoid
If you do use vintage red or ivory Fiesta, avoid these situations that increase uranium leaching:
- Hot foods and liquids: Heat increases the rate at which uranium can leach from the glaze
- Acidic foods: Tomato-based sauces, citrus fruits and juices, vinegar-based dressings, and other acidic items significantly increase uranium leaching
- Long contact times: Don’t use these pieces for storing food or letting dishes sit for extended periods
- Microwaving: Never microwave food in a radioactive Fiesta (also, vintage Fiesta isn’t designed for microwave use anyway)
- Dishwashers: The harsh detergents and high heat can degrade the glaze over time, increasing future leaching potential
Special Populations Should Exercise Extra Caution
Certain groups should be more cautious about any uranium exposure:
- Pregnant women: Developing fetuses are more sensitive to radiation
- Young children: Children’s bodies are more vulnerable to radiation effects, and they have more years ahead for cumulative exposure effects to potentially manifest
- People with compromised immune systems may be more susceptible to any health effects
For these groups, it’s wisest to avoid using radioactive Fiesta for food service entirely.
Chipped or Damaged Pieces Pose Higher Risk
If your vintage red or ivory Fiesta has chips, cracks, or crazing (fine cracks in the glaze), the risk of uranium leaching increases significantly.
Damaged pieces expose more of the clay body and create more surface area for uranium to dissolve into liquids.
Chipped pieces should definitely not be used for food and should be handled carefully, even for display.
Expert Recommendations: The consensus among health physicists, the EPA, and vintage dinnerware experts is:
- Display is safe
- Occasional use is acceptable with non-acidic foods
- Regular use is not recommended
- Never use damaged pieces for food
- When in doubt, treat them as decorative collectibles rather than functional dinnerware.
A Balanced Perspective
Is Fiestaware radioactive? Yes, some of it is. Is it dangerous?
The risk is low but not zero. Making an informed decision requires weighing the very small health risk against your personal circumstances, the historical and collector value of the pieces, and your intended use.
Many collectors choose to use their vintage Fiesta occasionally while following safety guidelines, while others prefer to keep radioactive pieces strictly for display.
Detecting Radioactive Fiestaware
If you own vintage Fiesta or are considering purchasing some, you may want to determine whether specific pieces are radioactive. Here are several methods for detecting uranium in Fiestaware glazes.
Using a Geiger Counter
The most definitive way to detect radioactive Fiesta is with a Geiger counter or similar radiation detection device.
These instruments can detect the beta and gamma radiation emitted by uranium-glazed ceramics.
You can purchase basic Geiger counters online for moderate prices, or you may be able to borrow one from a local university physics department, some libraries, or hobbyist groups.
To test a piece, turn on the Geiger counter and establish background radiation levels in your testing area.
Then hold the detector close to (or touching) the surface of the Fiesta piece. If it’s radioactive red or ivory, you’ll hear increased clicking and see higher readings on the display.
The closer you get to the surface, the higher the count should go if uranium is present.
Visual Identification
While not foolproof, you can make educated guesses based on color and age:
- Red pieces: If you have vintage red Fiesta (backstamped “FIESTA HLC USA”), it’s very likely radioactive if produced before 1973
- Ivory pieces: All vintage ivory Fiesta (1936-1951) contain some uranium
- Other colors: Vintage colors other than red and ivory are not radioactive
- Modern Fiesta: Anything produced from 1986 onward is uranium-free
Check the backstamp to help date your pieces. However, remember that not all red is radioactive. Modern red Fiesta uses different, safe glazes.
Ultraviolet Light Test
Some uranium compounds fluoresce under UV (black light) illumination, glowing bright yellow-green.
However, this test isn’t entirely reliable for Fiestaware because the specific uranium compound and glaze formulation may not fluoresce visibly, and other glaze components might also fluoresce.
A positive UV fluorescence test suggests possible uranium content, but a negative result doesn’t guarantee its absence.
Professional Testing Services
If you want absolute certainty, professional testing labs can analyze the glaze composition using X-ray fluorescence (XRF) spectroscopy or other methods.
This is typically only necessary for very valuable pieces where authentication matters for collector value, or if you have specific health concerns.
What to Do If You’re Unsure: If you can’t definitively determine whether your vintage Fiesta contains uranium, err on the side of caution:
- Treat vintage red and ivory as potentially radioactive
- Follow the safety guidelines for radioactive pieces
- Use other colors without concern
- Consider getting ambiguous pieces tested if it matters for your peace of mind
Remember the Post-1959 Red Complication
One tricky area is the red Fiesta from 1959-1972.
Some collectors report that later pieces in this range may have reduced uranium content or none at all as formulations changed, while earlier pieces from this period definitely contain uranium.
Without testing, assume 1959-1972 red is radioactive unless proven otherwise.
What About Other Radioactive Dinnerware?
Fiestaware isn’t the only vintage dinnerware that contains uranium; it’s simply the most famous example.
Understanding the broader context of uranium in glass and ceramics helps put the Fiesta situation in perspective.
Vaseline Glass and Depression Glass
“Vaseline glass” is a yellow-green glass that contains uranium, giving it a distinctive fluorescent glow under ultraviolet light.
This glass was popular in the late 19th and early 20th centuries for decorative items, dinnerware, and even serving pieces.
Some Depression-era glass in yellow and green colors also contains uranium. These items are radioactive at similar levels to Fiestaware and are subject to the same safety considerations.
Other Pottery with Uranium Glazes: Several other American pottery companies used uranium oxide in their glazes during the same era:
- Harlequin dinnerware (also by Homer Laughlin): The tangerine color contains uranium
- Bauer Pottery: Some orange and red-orange pieces contain uranium
- Hall China: Certain colors in vintage Hall patterns used uranium glazes
- Various other manufacturers: Many smaller pottery companies produced uranium-glazed items
Additionally, decorative tiles, especially orange and red ones from the 1930s-1950s, sometimes contain uranium.
European Ceramics: Uranium use in ceramics wasn’t limited to the United States.
European manufacturers, particularly in England, Germany, and Czechoslovakia, also produced uranium-glazed pottery and porcelain. Some imported vintage pieces found in America today contain uranium.
Orange is the Key Color: Across different manufacturers and types of items, bright orange and orange-red glazes are the most likely to contain uranium.
This distinctive color was difficult to achieve with other compounds, making uranium oxide the colorant of choice during this era.
The Decline of Uranium in Consumer Products: By the 1970s, increased awareness of radiation hazards and tighter regulations led manufacturers to phase out uranium from consumer products.
Today, uranium use in dinnerware and decorative items is essentially non-existent in newly manufactured goods.
Collecting Radioactive Glass and Ceramics: Despite (or perhaps because of) their radioactive nature, uranium glass and ceramics have dedicated collector communities.
The UV fluorescence of vaseline glass makes it particularly popular. Collectors follow the same safety guidelines as Fiesta collectors: display is fine, but regular use for food service is discouraged.
Should You Get Rid of Radioactive Fiestaware?
If you own radioactive Fiesta pieces, you face a decision: keep them, sell them, or dispose of them.
There’s no single right answer; it depends on your circumstances, concerns, and how much you value these historical pieces.
The Collector Value Perspective
Vintage red Fiesta, particularly pieces from the original 1936-1943 period, is highly sought after by collectors.
The radioactivity doesn’t diminish value; in fact, for some collectors, it adds to the historical interest and authenticity.
These pieces, especially in good condition, can command premium to high-end values in the collector market.
If you have inherited or purchased radioactive Fiesta, consider that these items represent both American design history and an interesting footnote in the history of consumer products and radiation awareness.
Many collectors are happy to own, display, and occasionally use these pieces with appropriate precautions.
Safe Display Options
If you want to keep your radioactive Fiesta but minimize any exposure:
- Display pieces in cabinets or on shelves away from areas where you spend extended time sitting or sleeping
- Keep them out of reach of children
- Maintain them in good condition to preserve the glaze integrity
- Handle them with awareness but not fear—brief handling poses no meaningful risk
- Consider using them purely as decorative art rather than functional dinnerware.
When to Consider Selling
You might want to sell your radioactive Fiesta if:
- You have young children or are pregnant and want to eliminate any potential risk
- You find yourself worrying about the pieces rather than enjoying them
- You inherited pieces you don’t particularly want or need
- You could use the money, and the pieces have significant collector value
- You’re downsizing and want to reduce possessions.
Radioactive Fiesta sells well in the collector market, so selling is a viable option that puts the pieces in the hands of knowledgeable collectors who understand and accept the minimal risks.
Proper Disposal Considerations
If you decide you don’t want to keep or sell your radioactive Fiesta, disposal requires some thought.
While the radiation levels are low enough that these items aren’t classified as radioactive waste requiring special handling, it’s still considerate to dispose of them thoughtfully.
Don’t simply throw radioactive Fiesta in the trash, where it could end up in a landfill. Instead, consider:
- Donating to a museum or historical society that might use them for educational purposes
- Selling to collectors who want them
- Offering them to universities for physics demonstrations
- Breaking them thoroughly and disposing of the pieces (though this seems wasteful given their collectibility)
- Contact your local waste management authority for guidance if you have a large quantity.
Balancing Safety and Historical Preservation
Radioactive Fiesta represents an interesting intersection of design history, industrial chemistry, and evolving understanding of radiation safety.
These pieces tell a story about a different era, when uranium was viewed as just another industrial material rather than something to be carefully controlled.
From a purely practical standpoint, keeping these pieces in your home poses minimal risk if you follow basic safety guidelines.
The decision to keep, sell, or dispose of them should be based on your comfort level, not fear.
Many people successfully collect and display radioactive Fiesta without any issues, while others prefer modern pieces without any concerns.
Making Your Decision: Consider these questions:
- Do you enjoy these pieces aesthetically and historically?
- Can you follow safety guidelines without anxiety?
- Do you have vulnerable people in your household (young children, pregnant women)?
- Is the collector value significant to you?
- Would selling them provide a meaningful financial benefit?
Your answers will guide you toward the right choice for your circumstances.
There’s no moral obligation to keep potentially radioactive items if they make you uncomfortable, but there’s also no need to fear them if you understand and manage the minimal risks.
Frequently Asked Questions
Can radioactive Fiestaware make me sick?
The radiation levels from vintage red and ivory Fiesta are low enough that simply owning, displaying, or occasionally handling these pieces won’t make you sick.
The primary concern is cumulative exposure from regular use, particularly if uranium leaches into food from acidic or hot items served on these dishes.
Brief contact and display pose negligible health risks.
How do I know if my Fiesta is the radioactive kind?
Radioactive Fiesta is limited to red pieces made between 1936-1943 and 1959-1973, and ivory pieces from 1936-1951.
All other vintage colors (blue, yellow, green, turquoise, etc.) are not radioactive.
Modern Fiesta from 1986 onward contains no uranium regardless of color.
The most definitive test is using a Geiger counter, which will show elevated readings for uranium-glazed pieces.
Is the Modern Red Fiesta Radioactive?
No. All modern Fiesta dinnerware produced from 1986 to the present day is completely uranium-free and safe for everyday use.
Modern red Fiesta achieves its color through alternative, non-radioactive glaze formulations. Only vintage red from earlier production periods contains uranium.
Can I safely eat off radioactive Fiestaware?
Occasional use with non-acidic, room-temperature foods poses a very low risk.
However, regular daily use is not recommended.
Never use radioactive Fiesta for hot foods, acidic foods (tomatoes, citrus, vinegar), or liquids that will sit in the dish for extended periods.
These conditions increase the potential for uranium to leach from the glaze into your food. Many experts recommend treating radioactive pieces as display items rather than functional dinnerware.
Will radioactive Fiesta set off radiation detectors at airports?
It’s unlikely, but theoretically possible if you’re transporting multiple radioactive pieces. The radiation levels are low, and airport detectors are primarily designed to find weapons-grade radioactive materials.
However, if you’re traveling with a vintage red or ivory Fiesta, it’s wise to pack them in checked luggage rather than carry-on to avoid any potential complications or questions.
Does radioactive Fiesta lose its radioactivity over time?
No. Uranium-238 has a half-life of 4.5 billion years, and uranium-235 has a half-life of 704 million years.
This means your radioactive Fiesta will remain essentially unchanged in its radioactivity for many thousands of years beyond any human timescale.
The pieces are as radioactive today as when they were manufactured and will remain so indefinitely.
Is it legal to own radioactive Fiestaware?
Yes, it’s completely legal to own, buy, sell, and collect radioactive Fiesta in the United States and most other countries.
These items are not classified as radioactive materials requiring special licensing or permits because their radiation levels are low and they’re sealed consumer products.
They’re treated as ordinary antiques and collectibles under the law.
Are there any benefits to the uranium glaze?
From a functional standpoint, uranium oxide created an exceptionally stable, vibrant color that didn’t fade over time—one reason vintage red Fiesta still looks brilliant today.
The glaze is also very durable.
However, there are no health or practical benefits to the radioactivity itself; it’s simply a byproduct of the colorant used.
Modern glaze technology can now achieve similar colors without uranium.
Conclusion
So, is Fiestaware radioactive? Yes—vintage red and ivory pieces from specific production periods contain uranium oxide and emit measurable radiation.
However, this fact needs to be understood in the proper context rather than feared unnecessarily.
The radiation levels from radioactive Fiesta are relatively low, especially compared to many natural and medical radiation sources you encounter regularly.
Simply owning and displaying these pieces poses negligible health risk. The primary concern is cumulative exposure from regular use, particularly when hot or acidic foods might cause uranium to leach into food.
For collectors and owners of vintage Fiesta, the key is making informed decisions.
Understanding which pieces are radioactive (red from 1936-1943 and 1959-1973, ivory from 1936-1951), following safety guidelines for use, and properly maintaining these pieces allows you to enjoy them while minimizing any risk.
Many collectors successfully display and occasionally use radioactive Fiesta without concern.
If you’re purchasing modern Fiesta, you can do so with complete confidence all Fiesta dinnerware produced from 1986 onward contains no uranium and is completely safe for everyday use.
Modern manufacturing has found alternative ways to achieve beautiful colors without any radioactive materials.
Whether you choose to collect, display, occasionally use, sell, or simply avoid radioactive Fiesta entirely is a personal decision based on your circumstances and comfort level.
These pieces represent a fascinating chapter in American design and industrial history, a time when uranium was viewed as just another useful material rather than something requiring special caution.
With knowledge and reasonable precautions, you can appreciate these historical pieces while keeping yourself and your family safe.
Disclaimer: This article provides general information about radioactive Fiestaware based on available research and expert opinions. It is not intended as medical or safety advice.
If you have specific health concerns or questions about radiation exposure, consult with a health physicist, radiation safety professional, or medical doctor.
Individual risk tolerance and circumstances vary, and you should make decisions about owning and using potentially radioactive items based on your own informed judgment.