Busan’s bad smell was leak of some odorizers

The source of the smell that panicked people in Busan on July 21 was likely a gas odorizer leak, a public and private joint investigation team announced Thursday.

The leak took place during transport, but due to the refusal of truck companies to cooperate with the investigation, it is not known which car or drum the leak originated from and therefore it cannot be verified whether the leak involved odorized gas or simply odorizer itself, before being added to gas.

Odorizers are chemicals added to odorless gas in order to enable detection in the event of a leak. Even a slight leakage can therefore trigger a powerful scent of onions or rotten eggs.

The team added that the smell reported in Ulsan on July 23 came from nearby chemical plants, but the exact company has not been identified.

During the past two weeks, there have been numerous reports of a mysterious gas-like smell in Busan and Ulsan, causing some to speculate that this signaled an upcoming earthquake or problems with nuclear power plants.

“The smell reported in Busan has shown to be from the leakage of odorizers normally added either to city gas or liquefied petroleum gas (LPG),” said Seo Yong-su, research fellow at the Center for Research Facilities of Pukyong National University, the head of the investigation. “It’s also possible that a small amount of chemicals or waste containing odorizers leaked.”

The team checked along the route of the odor through CCTV footages and investigated waste companies around Haeundae and Gangseo District. The investigation team also conducted a sensory test with 37 reporters of the gas, with the result of 34 (91.9 percent) responding that the odor was similar to the smell of odorizers.

According to Seo, had the smell been from a fixed origin, it would have moved across seven kilometers (4.34 miles) with a wind speed of 2 m/s (4.47 mph). But the odor traveled 32 kilometers around the coastal road, which is similar to the usual speed of trucks.

BY CHUN IN-SUNG [shon.jihye@joongang.co.kr]