Lotte Mart, one of the manufacturers of a humidifier disinfectant that allegedly caused lung damages that claimed 143 lives, on Monday officially apologized and vowed to provide due compensation to the victims and their families.

The announcement marks the first ever public action taken by a maker of the toxic disinfectants in question since a probe on the case began in 2011. It also comes as the prosecution is set to summon executives of Lotte Mart, alongside three other firms, for questioning this month.

“We express our sincerest apologies to the humidifier disinfectants victims and their families for the grievances they have endured up to now,” Lotte Mart CEO Kim Jong-in said in a press conference in Seoul.

Vowing to fully cooperate with the prosecution on the case, Kim said the firm would set aside roughly 10 billion won ($8.68 million) for compensating the victims and their families.

Lotte Mart plans to create an independent committee to be put in charge of the compensation process. It will set appropriate guidelines and measures for the victims proven to have been adversely affected by its in-house humidifier disinfectant brand Wiselect, sold from November 2006 to September 2011.

“We fully acknowledge our belated response and lack of activism in determining the cause of this issue, figuring out the scale of the damages and offering solutions. We make today’s announcements well knowing that such actions can no longer be delayed,” Kim said.

Meanwhile, representatives of the toxic disinfectant victims and local consumer groups raised questions over Lotte Mart’s apology, criticizing it as a strategic move that comes just one day ahead of its scheduled summoning.

The prosecution is currently investigating Lotte Mart, alongside Homeplus, Cefu and Reckitt Benckiser, the producer of Oxy Ssak Ssak, the disinfectant used by about 70 percent of the victims, with a focus on determining their responsibility for the sale of the toxic disinfectants.

Their products contained polyhexamethylene guanidine phosphate, a chemical known for its powerful sterilizing effects compared to other substances. PHMG is “poisonous when inhaled in powder format at room temperature,” according to its local manufacturer SK Chemical.

In 2011, the government discovered a “significant association” between lung damage and the use of the humidifier disinfectant, after multiple deaths, including pregnant women and infants.

According to the government, a total of 22 people have died from using Lotte’s Wiselect. As of January 2016, around 130 people have identified themselves as victims of Lotte’s product, according to the Asian Citizen’s Center for Environment and Health, a local advocacy group.

By Sohn Ji-young (jys@heraldcorp.com)