G�r�e�e�n�h�o�u�s�e� �g�a�s�e�s� R�e�q�u�i�r�e�m�e�n�t�s� �f�o�r� �g�r�e�e�n�h�o�u�s�e� �g�a�s� �v�a�l�i�d�a�t�i�o�n� �a�n�d� �v�e�r�i�f�i�c�a�t�i�o�n� �b�o�d�i�e�s� �f�o�r� �u�s�e� �i�n� �a�c�c�r�e�d�i�t�a�t�i�o�n� �o�r� �o�t�h�e�r� �f�o�r�m�s� �o�f� �r�e�c�o�g�n�i�t�i�o�n: 2007