As per reports, Acting President Choi Sang-mok directed relevant government agencies to implement emergency environmental measures as ultrafine dust warnings were issued for parts of South Korea on Monday (20 January). He instructed the environment ministry and provincial governments, among others to implement dust reduction measures, mandating high-emission facilities and construction sites to modify or reduce their operating hours to protect workers. He further mandated that these measures be communicated to the public.

The environment ministry stated that the control measures will go into effect from 0600-2100 hours on Tuesday (21 January). Earlier on Monday (20 January), ultrafine dust warnings, for particles smaller than 2.5 micrometers in diameter, were issued for parts of the greater Seoul area (Seoul, Incheon and Gyeonggi Province) and South Chungcheong Province.