The HPL shutdown led to the closure of nearly 150 such units, rendering thousands jobless, IPF said in a statement.
The HPL plant was shut down on July 6 following a technical snag at the mother naphtha cracker unit.
There was no response from HPL officials when contacted for information on when the plant was expected to reopen.
Before the shutdown, the plant was operating at sub-optimal capacity, owing to shortage of the key input naphtha.