South Korea’s supreme court has upheld a four-year prison sentence for the CEO of a battery manufacturer where a factory fire in 2024 killed 23 employees and injured nine others.

A district court initially sentenced both Park Soon-kwan, CEO of primary lithium battery firm Aricell and his senior executive son, Park Joong-un, to 15 years in prison following the fire at the plant in Hwaseong, 45km south of Seoul.

Their sentences were cut to four and seven years, respectively, by an appeals court, after some charges were overturned and compensation settlements with bereaved families were taken into account.

On October 20, the supreme court upheld the appeals court rulings, including a fine of KRW1 million ($750) for Park Joong-un. The court also upheld a KRW800 million corporate fine against Aricell.

The appeals court had previously cleared Park and his son of a key charge that they failed to install an emergency exit on the factory’s second floor. In explaining its decision, the appeals court said safety rules did not specifically require exits on every floor.

According to the supreme court’s ruling, seen by Batteries International, some of those caught up in the fire included foreigners working illegally.

At the time of the fire, the Aricell factory housed an estimated 35,000 battery cells on its second floor, where batteries were inspected and packaged.

The supreme court said there had been a failure to manage potential overheating of batteries at all stages after electrolyte injection and vital equipment such as heat and gas detectors were not installed.

Aricell’s risk assessment procedures failed to adequately account for the specific hazards of manufacturing batteries using lithium, which poses an explosion risk, the supreme court said.