class codes of mechanically active substances (S)

Applies to enclosed storage locations where precautions have been taken to minimize the presence of dust and sand. Conditions are specified in IEC 60721-3-1:2018, Table 5.

Applies to enclosed storage locations not situated in proximity to dust or sand sources and with no precautions to minimize the ingress of dust or sand. Such enclosed storage locations could include shipping containers. Conditions are specified in IEC 60721-3-1:2018, Table 5.

Applies to enclosed storage locations in close proximity to sand or dust sources, including urban area and with no precautions to minimize the ingress of dust or sand. It also Applies to exposed storage locations situated in areas not subject to natural dust storms or significant industrial activity. Conditions are specified in IEC 60721-3-1:2018, Table 5.

Applies to exposed storage locations which may be exposed to wind-driven dust and sand either due to natural conditions or due to industrial activity producing blown sand or dust. Conditions are specified in IEC 60721-3-1:2018, Table 5.