Even as they grapple with irritants, firms seeking to promote usage of LPG as automobile fuel are looking forward to their meeting with the Chief Secretary on Wednesday. The meeting, more a presentation by the Tamil Nadu Pollution Control Board (TNPCB) on the advantages of promoting LPG as a 'green' alternative to fuel automobiles, they hope, should pave the way for the State Government to announce a single window clearance system for the projects.