It follows the Orissa governments decision to implement an environmental institute’s pollution recommendations.
As a result, 12 aluminium and power projects have to wait until the Nagpur-based National Environmental Engineering Research Institute (NEERI) presents its final recommendations in December.
Then Orissa government said it wanted to prevent more pollution in the industrialised Sambalpur-Jharsuda belt.
All projects have been put on hold while further environmental research is carried out.
The Orissa government said new projects would only be considered if they proved their environmental credentials.
Power projects pushed into uncertainty include the 1320MW IB Thermal Power Station (proposed 3 and 4 units) and the 1080MW Captive Power Plant of L&T's aluminium project at Bhadrapalli.
NEERI's initial report stated measures to minimise ground-level major pollutants such as sulphur dioxide and suspended particulate matters in the area.