This legal opinion provides an analysis of the claims that ISEAL Alliance can make in respect of the conformity of private sustainability standards with the principles and disciplines as laid down by the World Trade Organization. In particular it assesses the extent to which the ISEAL Code of Good Practice for Setting Social and Environmental Standards is consistent with these disciplines. The legal opinion provides an update to the 2006 ISEAL – CIEL Legal Opinion entitled “International Standards and Technical Barriers to Trade".