influence of oil stain to the siemens electrical equipment

Dear All

              Recently   I found the switch and the  Electric cables be covered with some oil stain which formed by the oil mist from the automoblie painting workshop. I want to judge about the influence of this oil stain to the siemens  electrical equipment.but what a pity! I did not found related data about this ,could you provid relevant technical data to assessment the impact and  to deal with it ?

    thank you very much!

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splitted from: 3WL Electrical Closing request