This part of ISO 20492 specifies methods for testing the edge seal strength, and partially testing the moisture and gas permeation through sealants, of glass insulating units. Other parts of ISO 20492 designate two approaches to the standardization of insulating glass units: approach 1 is intended for use in markets such as North America; and approach 2 is intended for use in markets such as Europe. The methods in this part of ISO 20492 are applicable only to approach 2, as defined and used in the other parts of ISO 20492. In cases where there is no protection against direct ultraviolet radiation at the edges, such as structural sealant glazing systems, it is necessary that additional European technical specifications be followed. See References [4] and [5].