Are Synthetic-Diamond Detectors Hazardous to Your Health?

In my seven-year run as a journalist in the close-knit diamond and jewelry industry, I’ve spoken to hundreds of people and heard numerous stories, including plenty of rumors, gossip and side comments. I have made it my mission to try and write pieces that make a difference to the people who operate within my sphere, from miners, dealers and retailers to insurance providers, technology creators and online influencers.

So when someone in the know recently mentioned their concerns about handheld synthetic-diamond detectors using exposed ultraviolet-C (UVC) light — which health experts say can cause skin irritation and aging, as well as cancer — I was determined to look into it. I set out to learn as much as I could about whether these machines harbor potential hazards.

The right wavelength

My first call was to Dr. Norman Kleiman, associate professor of environmental sciences at Columbia University’s Mailman School of Public Health. He is also the director of the school’s radiation safety officer training course and its eye-radiation and environmental research laboratory.

“The range for UVC is around 199 nanometers, up to about 300 nanometers, which is part of the electromagnetic wavelength band,” he explains. “It has the potential for damaging cells and…for causing damage to DNA, leading to mutation and potentially leading to cancer. But this is all a probability question. It’s a question of how long, how much, how frequently you’re exposed, and what you are exposed to.”

In general, he continues, “254 nanometers is the sweet spot [for UVC light], because that’s the maximum absorbance of the molecules in DNA, but that doesn’t mean that 255 nanometers or 253 nanometers is safe. These [detection] machines are 275 nanometers, and that is close enough to 254 that there is a risk for DNA damage. There’s also a risk for damage to proteins, which [absorb the radiation] most strongly at 280 nanometers.”

Depending on how deeply the UVC gets into the skin or the eye, it could potentially cause melanomas, pigmented cells, cataracts and more, but the primary danger is skin cancer, according to Kleiman. While he couldn’t give me a full assessment without proper testing, his initial impression was that the risk would be on par with tanning beds or the UVC lights that nail salons use for gel polish — both of them proven skin-cancer hazards.

Although the US National Institute of Environmental Health Sciences (NIEHS) hasn’t studied lab-grown detectors, it has studied the use of UVC light. A 2021 analysis by its National Toxicology Program characterized UVC light as “reasonably anticipated to be a human carcinogen.” However, the report did not include estimates of cancer risk, explains a spokesperson for the institute, because there are many factors that affect whether a person develops cancer. Those include the carcinogenic potency of the substance, the level and duration of exposure, and the individual’s own susceptibility to carcinogenic elements.

“No epidemiological studies have adequately evaluated the carcinogenicity of UVC in humans,” the spokesperson says. “In studies of exposure to artificial devices [of any kind that emit] UVC, the devices also emitted other [types of UV rays]. Exposure to high doses of radiation from devices emitting primarily UVC caused skin cancer in rats and mice.”

Providing protection?

Handheld synthetic-detection devices that use UVC light are classified as lamps under international safety standards. But a person using other types of UVC lamps would not necessarily be placing them directly against the skin; those using synthetics detectors would — especially in the case of melee.

Of course, not all detectors use the same testing methods. Those that involve placing the diamonds in closed chambers, for instance, don’t expose human skin and tissue to the light. Do the makers of handheld devices offer any options to mitigate exposure?

Perusing the boxes of several handheld testers, I noticed that some had warnings and safety information, ranging from a highlighted note about the possibility of eye or skin irritation if one failed to use protective gear, to a message that the product posed “no photobiological safety hazard” during continuous use without safety gear, “but not for more than 40 minutes.”

Those with warnings also came with gloves and eye protection. However, others had neither protective gear nor warnings, despite using exposed UVC light at 275-nanometer wavelengths.

One company told me that while its detector conformed to international photobiological-safety standards for lamps and lamp systems, and therefore did not require safety glasses or gloves, the company provided them anyway and insisted in the product manual that the user wear them just in case. The risk warning for this standard applies to lamps that are on continuously for 40 minutes or more, according to the company; its own device turns on for 1.5 seconds at a time.

Who’s checking?

While a quick email to the Jewelers Vigilance Committee (JVC) turned up no logged complaints about UVC-based testing machines, the Gemological Institute of America (GIA) — which has its own lab-grown testers — expressed concern over other companies’ use of UVC.

Despite the devices’ convenience, “UVC light has a 275-nanometer wavelength, which can be very harmful to the skin and eyes,” says GIA executive vice president Tom Moses, echoing Kleiman’s assessment. Moses, who is also the institute’s chief laboratory and research officer, recommends wearing eye protection and gloves when using such equipment.

I also checked in with the Natural Diamond Council (NDC), which operates Project Assure. The program assesses the performance of diamond-verification systems through “rigorous” testing, according to the NDC’s website. However, that testing focuses on the machines’ ability to distinguish between synthetics and natural, and does not necessarily extend to health and safety, according to NDC spokesperson Sophie Bullinger.

The manufacturers provide “signed statements that the machines are safe for use per a list of European Union (EU) guidelines for electronic devices,” she explains. “The job of Assure is not to test all of these safety issues, but we provide the statements to show that it has been done. Assure exists specifically to test the performance and accuracy of the machines.”

What that means to me is that there’s little to no oversight within the diamond industry itself as to whether these devices are dangerous. Instead, the trade relies on the safety guidelines of the country where the device is tested, be it an EU nation, Singapore, Thailand, the US or any other. Furthermore, because most testers are treating the device like a lamp, they may not take into account that even if it’s on for only 1.5 to 2 seconds at a time, those numbers can add up throughout the day. One industry insider I interviewed knows retailers and manufacturers that turn on their detectors up to 100 times daily.

From theory to practice

I could have stopped there, concluding that handheld detectors were likely dangerous and that users should proceed with caution, but I wanted a more decisive answer. Are they dangerous? If so, how dangerous? And what exact precautions do users need to take when testing diamonds?

With that in mind, I contacted Kleiman once more and asked him if he was interested in testing the devices himself to provide a real and accurate picture of their safety. He happily agreed. I had several devices delivered to his office, put my faith in his team, and waited anxiously for two weeks to get my results.

The first order of business was to figure out what the safety and danger thresholds were. Kleiman’s team began by measuring radiance — the length and veracity, or power, of the UVC beam — at the minimum and maximum expected distances: when the diamond sits directly in a bare palm, and when the user holds a ring by the band and touches the detector tip to the diamond’s surface. The highest radiance came to 0.4 millijoules per square centimeter. At that rate, if the machine was directly touching your hand, you would reach the safety threshold in about seven seconds. Since it takes about a second to perform the diamond testing, that means the operator would be limited to using the detector seven times a day.

Of course, comments Kleiman, “risk is a relative term. Some people may have some underlying disease that makes them more vulnerable. Some people don’t repair DNA as well as other people. It’s probability. I can only tell you that below this limit, there is little risk, and above it, it can be risky.”

He points to sunburn as an example: “If you go out in the sun for 20 minutes, you’re not going to get a sunburn, but if you go out for two hours, you might. So there’s a limit below which it doesn’t happen. That’s true for sunburn; it’s not true for cancer. Cancer is a risk at any exposure [to UVC light], but the lower the exposure, the lower the risk. We try to set the risk as low as reasonably acceptable, but [it’s] never zero.”

The final result

After fully testing the devices, Kleiman’s team determined that using them at the furthest point — while holding a ring — carries little risk to the user’s health. The risk increases for a loose diamond in one’s fingers, and even more for melee on the palm. If someone tested diamonds 100 times at the highest risk level, that would be 10 times the threshold limit — a health-risk factor of 1 in 1,000.

Most people are probably not testing that many stones at the highest risk level on a daily basis. As such, Kleiman concludes, while there is always a risk, the potential for the device to cause cancer is very low. He strongly advocates using safety gear regardless.

“Those devices that come without safety gear are worrisome,” he maintains. “If I were their general counsel, I would suggest they put it there just to cross their T’s and dot their I’s. If you really want to be prudent, you should wear gloves, especially if you test a lot and you use melee diamonds.”

Image: How safe is the trade when it comes to testing diamonds? (Shutterstock)

This article is from the October-November 2024 issue of Rapaport Magazine. View other articles here.