Having humidifier is very popular in Korea especially in dry weather like winter.  Humidifier disinfectant was first introduced in Korea in early 1990s. Humidifier disinfectant was advertised as being "safe to humans" and easy to use by adding into the water tank and soon became a must-have in many families and offices. There were around 20 similar products in market, and among them, Oxy Ssackssack took 80% market share in Korea. At that time, Korea is the only country that used the humidifier disinfectant.

A few years later in every spring, unidentified fatal lung diseases were noticed among children and pregnant women. Finally in 2011, Korean government started investigation and determined that the disinfectant used in humidifier was the cause of the unidentified fibrous lung diseases. The investigation showed that the two ingredients having sterilizing effect on the water of humidifier were the toxic agents, which was confirmed from experiments on rats which showed similar symptoms as victims. So far, Korean government assessed 530 cases including 140 deaths for victims of humidifier disinfectant. Sadly, most of the victims were pregnant women and infants and many of them were family members because one family shared the same humidifier at home.

Although there were lawsuits against the humidifier disinfectant manufacturers in Korea and the Korean Free Trade Commission has confirmed that the major manufacturer was guilty of wrongly promoting its product as "safe for humans," most of the victims' families have not sufficiently compensated from either manufacturers or government. All they received was the medical expense from government, not even an apology nor damages by the Oxy Ssackssack manufacturer. Had it been a law or regulation that restricted use of certain toxic material in an inhaling tool such as humidifier, such a huge disaster could have been avoided or at least more reduced than now.  

Despite the continuous request for responsibility by the victims' families, the major manufacturer keeps avoiding to take any liability.  The victims' families and Korean activists are now discussing to file a lawsuit in England, the location of the headquarters of the Oxy Ssackssack manufacturer.

http://www.anroev.org/2015/05/07/stop-killing-innocent-babies-and-pregnant-women-boycott-products-by-reckitt-benckiser/

https://www.researchgate.net/profile/Jung-Hwan_Kwon2/publication/221865730_Fatal_Misuse_of_Humidifier_Disinfectants_in_Korea_Importance_of_Screening_Risk_Assessment_and_Implications_for_Management_of_Chemicals_in_Consumer_Products/links/0c96053029c25d9af8000000.pdf