This standard specifies the graphic signs and their functions for environmental protection of sewage discharge outlets, waste gas discharge IZl and noise discharge sources. This standard is applicable to the supervision and management of the environmental protection administrative department on sewage discharge IZl, waste gas discharge IZl and noise emission sources.
GB 15562.1-1995 history
1995GB 15562.1-1995 Graphical signs for environmental protection--Discharge outlet(source)