This International Standard specifies a method for the determination of the corrosiveness to copper of liquid petroleum products and certain solvents. Volatile products, having a maximum vapour pressure of 124 kPa at 37,8 degrees Celcius are included. Volatile products with a vapour pressure above 124 kPa at 37,8 degrees C should be tested according to ISO 6251. Electrical insulating oils should be tested according to ISO 5662.