One of a series addressing the testing and sampling of varnishes, paints and related products. Defining a method for determining the volatile organic compound (VOC) content of varnishes, paints and their raw materials. This part may be used where the VOC content is expected to be greater than about 15% by mass. When the VOC content is expected to be greater than 0.1% by mass and less than about 15% by mass, ISO 11890-2 shall be employed. It is assumed that the volatile matter is either organic or water in this method. However, other volatile inorganic compounds may be present and may need to be quantified by another suitable method and allowed for in the calculations.