A high court has issued a four-year prison sentence for the former heads of SK Chemicals and Aekyung Industrial for the manufacture and sale of toxic humidifier disinfectants, overturning a lower court ruling. 

The Seoul High Court handed down the verdict on Thursday for Hong Ji-ho and Ahn Yong-chan who have been indicted on charges of professional negligence resulting in death. The two former CEOs, however, were not detained in court upon the sentencing. 

In issuing the ruling, the court said the accused had made the decision to commercialize the disinfectants without conducting proper safety tests.

The court said the humidifier disinfectant scandal is virtually a case in which a test was conducted on the toxicity of the disinfectants on the entire nation for a long period of time. 

It went on to say that random people had suffered tremendous pain without having any answers,  adding that many of the victims had their dignity violated, including in the form of death which the court described as "irreversible damage."

Hong, Ahn and eleven other officials of SK Chemical and Aekyung Industrial were indicted in July 2019 for causing 12 people to die and 86 others to suffer lung disease or asthma by manufacturing and selling the humidifier sterilizer called "Humidifier Mate,” which contained chloromethylisothiazolinone and methylisothiazolinone, which are potentially dangerous chemicals. 

According to the environment ministry’s portal on supporting victims of the disinfectant scandal, as of December 31 of last year, five-thousand-691 people had been recognized as victims of the scandal. Of that total, one-thousand-262 have died.