The most important measure was the third prevention order implemented in May, 1897 which mandated Furukawa to make filtration basins and deposit basins and deposit sites, and to install desulphurization equipments on chimneys.
特に大規模なものは1897年5月の第3回目の予防令で、古河側に、排水の濾過池・沈殿池と堆積場の設置、煙突への脱硫装置の設置を命令した。