South Korea's antitrust watchdog said Wednesday that it has closed an inspection on two local humidifier sterilizer manufacturers, citing a lack of evidence, amid a ballooning toxic disinfectant scandal that has resulted in numerous deaths and illnesses here.

Aekyung Industrial Co. and E-Mart Inc. had allegedly manufactured and sold humidifier cleansers using the chemicals chloro-methylisothiazolinone and methylisothiazolinone between 2006 and 2011.

The Fair Trade Commission had accused the two companies of having not indicated the health risks of such chemicals on their products in 2012 but acquitted them, saying that the lethal effects of CMIT and MIT when inhaled have not been proven.

However, the FTC resumed the inspection in 2016 as the humidifier disinfectant case, one of the worst scandals involving a consumer product using poisonous chemicals, has been making headlines in South Korea.

But the watchdog closed the case again, citing that Aekyung and E-Mart are not liable to write the possible health hazards on the products as there is still no enough evidence that the chemicals are fatal.

In its earlier examination, the FTC filed charges of false advertising against Oxy Reckitt Benckiser, the South Korean unit of the British company Reckitt Benckiser Group PLC.

The company had sold home humidifier sterilizers using other chemicals, such as polyhexamethylene guanidine, known for causing death when people inhale them, without proper warnings on the product.

The South Korean prosecution has launched an investigation into the company as more than 100 deaths were reportedly caused by Oxy's humidifier disinfectant in the country. (Yonhap)