“Neck fans” are a popular item in the summer which can be worn around the neck and help fight off heat.

Without having to be handheld, the gadget is praised as a clever invention by those who want a cooling breeze just for themselves while on the go, such as joggers, delivery workers or just outdoor lovers.

According to Shinsegae International’s lifestyle brand Jaju, sales of summer home appliances including portable fans saw a 144 percent jump between June 27 and July 10 compared to the previous two weeks. “As heat waves and humid weather continue, neck fans or handheld fans appear to be particularly more popular,” one official at Jaju said.

The mood, however, changed sharply late July when one civic group alleged that the electromagnetic radiation found in neck fans can be “dangerous,” putting their safety under scrutiny.

“As the fan is worn around the neck, your brain can’t escape the ‘attack’ from the electromagnetic radiation,” said Choi Ye-yong, director of Asian Citizen’s Center for Environment and Health.

Citing its own study into portable fans from 10 unspecified brands, the group said “children and adolescents should especially avoid” using neck fans, while calling on the government to immediately look into the health risks the gadgets pose to the public.

According to the group, the levels of electromagnetic field detected from the products averaged 188.77 milligauss, with the highest reading of 421.2 mG.

It said the readings far exceeded 4 mG, a level global studies have found to be linked to an increased risk of leukemia among children, although no biological mechanism for this has been found. According to the group, the World Health Organization’s International Study for Cancer has classified electromagnetic fields as Group 2B, a possible human carcinogen.

As the claim stoked public concern, the Ministry of Science and ICT conducted an investigation and concluded that neck fans are safe to use.

“The level of electromagnetic radiation generated by the handheld and neck fans is between 37 and 2.2 percent of the international safety standard. They are safe for the human body,” the ministry said in a statement.

The maximum level allowed in Korea is 833 mG at 60 Hz, the most common frequency of electricity, which is lower than the 2,000 mG limit set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), the ministry explained.

It added its study was conducted based on the National Radio Research Agency’s measurement standard which follows that of the International Electrotechnical Commission. The civic group’s study, however, failed to factor in the fact that radiation affects the human body differently depending on frequency levels.

“It is more reasonable to adhere to the standard of the International Commission on Non-Ionizing Radiation Protection which is the case in most countries at the recommendation of the WHO,” said Professor Kim Nam at the School of Information and Communication Engineering of Chungbuk National University, pushing back on the findings from the civic group’s study.

Controversies the safety of wearable gadgets are nothing new.

Apple’s AirPods, along with a handful of Bluetooth headsets, have also come under scrutiny. A 2021 Reuters article debunked warnings widely circulated on social media against the use of the electric earbuds, saying “There is no established evidence to warrant advising people against using wireless devices like Bluetooth headphones.”

As for the neck fans, the Seoul-based group is not backing down from its claim that the device’s risk is being underestimated, calling for more research.