Humidifier sterilizers shouldn’t be used: KCDC

The Korea Centers for Disease Control and Prevention issued a strong warning against the use of sterilizers in home humidifiers yesterday, after preliminary test results on mice showed that they suffered from the same pulmonary fibrosis that has mysteriously killed pregnant women since May.

Since last May, seven pregnant women and a man in his 40s have been sickened. Four of the pregnant women died.

“Although these are only preliminary results, considering the approaching winter season when many people start using humidifiers at home, we have decided to make an announcement to make sure people stop using any kind of sterilizers for their humidifiers as they are highly likely to be the cause of the illness,” said Jun Byung-yool, director of the KCDC, at a press briefing yesterday.

The KCDC began animal testing in late September after suspicions arose in late August that sterilizers, which are added to the water tanks of humidifiers to kill micro-organisms, were the mysterious cause of the pneumonia and pulmonary fibrosis.

According to the KCDC, 80 mice were divided into four groups, with three of the groups inhaling air from humidifiers that used sterilizers. One group was left as the control.

The KCDC said that they selected three brands with the largest market shares to conduct the test. The rest of the 13 brands will be tested in order.

After a month, necropsies on the mice found that two groups suffered from pulmonary fibrosis, or scarring of the lungs, the same effect that killed the four pregnant women this year, the KCDC said.

“If final results prove the cause-and-effect relationship between sterilizers and the illness, we’ll immediately recall the products.” The KCDC said final results are expected to be announced next week at the earliest.

The Ministry of Health and Welfare, meanwhile, said it would consider bringing sterilizers under the auspices of the Korea Food and Drug Administration before they enter the market.

Instead of sterilizers, the KCDC said cleaning humidifier water tanks was enough to ensure clean water. The KCDC advised people to thoroughly clean tanks once a day with clean hands.

By Yim Seung-hye [sharon@joongang.co.kr]