A pipeline carrying chemicals inside the plant got choked up, leading to the gasket opening up and then causing the explosion, they said.
The opening up was discovered in time and necessary precautionary steps taken helping avert casualties, they added.
The injured has been identified as Atul Ravindra Nachane (24), a worker at the facility.
When contacted, a RIL spokesperson confirmed the incident and said there was a minor injury to one of the workers who was taken to an in-house medical facility.
The RIL scrip closed 1.74 per cent down at Rs 1,381.05 a piece on the BSE today, as against a 0.44 per cent correction in the benchmark.