Four days of maintenance works on the blast furnace is expected to finish today and BlueScope's manager of manufacturing, John Nowlan, said residents had nothing to fear from any "emissions".

"The community may see more activity on site in the next few days as we start back up," he said.

"This may include some visible emissions and possibly some noise, all of which is normal for this operation and have occurred many times in the past during similar start-ups.

"We have conducted exhaustive safety and environmental risk assessments as part of this process, as we do for all maintenance work."

More than 400 workers had been employed to undertake the maintenance on the blast furnace.

"We continually monitor the performance of all our plant and equipment to optimise performance," Mr Nowlan said.

BlueScope has had a promising start to 2014, with its share price yesterday sitting at $5.77 - a substantial improvement on its August 2012 low of about $1.50.

It seems the market hasn't been scared after BlueScope's plan to take over OneSteel's sheet and coil distribution business hit a brick wall late last year, with the Australian Competition and Consumer Commission finding "strong concerns" about the deal's impact on the market.

Weeks before its decision, the ACCC announced it would not oppose BlueScope's purchase of the Orrcon Steel business from Hills Holdings.

BlueScope has also recently made the decision to add an additional ship to its New Zealand iron ore sands export operations, which is expected to go online in 2016 and export 1.3 million tonnes of slurry per annum from the Tahoroa Mine.