South Korean prosecutors will be wrapping up the five-month investigation into toxic humidifier disinfectants that left at least 140 dead and hundreds more affected since 2011, according to officials on Sunday.

The special probe team of Seoul Central District Prosecutors Office is expected to press charges against some 20 people related to the incident, including 12 already arrested on charges varying from professional negligence to false advertising that products were safe. The subjected companies include Oxy Reckitt Benckiser, Lotte Mart, Home Plus and Cefu. 

For Oxy, formally renamed Reckitt Benckiser Korea since 2014 and responsible for the largest number of damage claims, its former CEO Shin Hyun-woo has been arrested for allegedly developing and selling the product in question without due safety precautions. Another former CEO, John Lee, has been indicted without physical detention.

Lotte Mart’s former sales director Noh Byung-yong was arrested and is being grilled with other Lotte Mart officials for selling private brand sterilizers based on the Oxy products without proper safety tests. Homeplus officials including former purchasing chief Kim Won-hee have also been arrested on similar allegations.

The prosecution arrested Butterfly Effect’s CEO, who has been revealed to have made Cefu based largely on information he gathered from the Internet.

Prosecutors have summarily indicted Oxy and Butterfly Effect for 150 million won in fine. ($128,146)

The prosecution, however, was unable to summon officials at Oxy’s parent company in Britain suspected to be related to the deadly incident. The officials plan to investigate them through an emailed questionnaire.

Investigators also stopped short of pinpointing which government officials are responsible for failure to recognize the safety hazards posed by the Oxy products until 2011.

Oxy held a closed-door meeting with the victims and their families on Saturday to explain their compensation plans for government-assessed class 1 and 2 victims. The 530 victims who registered themselves as victims have been classified from classes 1 through 4, with class 1 denoting the strongest connection.

Oxy CEO Ata Safdar vowed to pay 150 million won to bereaved families and those who were definitely harmed by the company’s products, and 100 million won to the rest of the 178 class 1 or 2 victims.

He also vowed to spend a portion of the company’s 10 billion won humanitarian funds on victims who do not belong to class 1 and 2.

But the victims and their families have expressed discontent with what they claim are inadequate plans, which they said looked to cover only the people the government assessed to be highly likely to have directly suffered from Oxy’s toxic humidifier disinfectant.

One participant said Oxy was vague on how it will compensate a case in which all members of a family have been harmed by their product.

“Choosing to hold a conversation only with those in class 1 and 2 appears to be an insult not only to the victims, but to the entire population of the Korean consumers,” said Gang Chan-ho, the spokesman for the victims and families.

By Yoon Min-sik(minsikyoon@heraldcorp.com)