Industries Minister Goutham Reddy said it may take up to 48 hours to neutralise the rest of the gas.
More than over 60 per cent of the toxic gas leaked from the chemical factory in Visakhapatnam has been neutralised and it will be completely gone in the next two days, authorities in Andhra Pradesh said on Friday, a day after 12 people died and hundreds fell ill by the accident.
Even though the styrene vapour leak was apparently contained within three hours, special chemicals identified as PTBC were flown in from Gujarat to Visakhapatnam to cool and neutralise the leakage.
Sources in the Chief Minister YS Jaganmohan Reddy's office said district collector V Vinay Chand had reported through a video conference that up to 60 per cent vapour has been neutralised.
Chemical disaster experts of the NDRF and NEERI had been flown in along with the consignment of PTBC and they visited the spot for assessing the situation.
The over 1,000 people evacuated from the area have not yet been given the permission to return home.
"All necessary measures like using added water are being taken to keep the temperature under control," they said.
Industries Minister Goutham Reddy said it may take up to 48 hours to neutralise the rest of the gas.
Over 400 people, including children, undergoing treatment in various hospitals here were out of danger and recovering from the effects of the vapour leak, sources said.
Deputy Chief Minister (Health) A K K Srinivas, Industries Minister Mekapati Goutham Reddy, Agriculture Minister K Kanna Babu and others visited the LG plant and also the King George Hospital and consoled the victims.
Talking to reporters, the Deputy Chief Minister said 305 people, including 52 children, were undergoing treatment in the KGH and another 121 in private hospitals.
"All of them are out of danger. Nobody is on ventilator support," he said.
In all, 554 people suffered from the vapour leak and 128 of them left for relief camps after preliminary treatment.
The Greater Visakhapatnam Municipal Corporation opened 17 relief camps in the city, where about 15,000 people evacuated from five villages in the plant vicinity were being provided safe shelter.
"The police, local youths, NDRF, SDRF and revenue department personnel did an exemplary job in shifting the people to safety after the vapour leak.
We appreciate and thank all of them," Mr Srinivas said.
The Deputy Chief Minister asked people not to return to their villages till the medical and health officials advised.
"The regular operation of the plant has not started and it was only under regular maintenance. The accident occurred due to some lapse in following the prescribed protocols," Minister Goutham Reddy said.
He said stern action would be initiated against those responsible for the leak.
"I told the South Korean Ambassador clearly that they should act in a responsible manner and take all steps as they do when such a mishap occurs in the USA or Europe," the minister said.
The state government identified 86 such industrial units and they would be allowed to restart their operations only after a safety audit.