Morwell locals are gathering evidence for a possible class action as Premier Denis Napthine visits the town, which has been engulfed in fire smoke since February 9.

The Hazelwood open cut mine fire, which has been choking the town for two-and-a-half weeks, could take months to extinguish.

As crews continue to face challenges battling the mine blaze, there is growing panic in the town about the possible long-term health impacts of the smoke.

Morwell residents living with smoke, fumes and falling ash from the fire say they have had enough.

"We are in the dark, we don't know what's going on," one resident said.

Another said: "No one knows what it's going to do to our long-term health."

Residents are being told they will not suffer any health problems from short-term exposure to the fine particles in the smoke.

Health risks travel further than flames

However, Ambulance Victoria and police are warning their female staff to stay away from the fire front if they are pregnant or trying to conceive.

Council workers have also been going door-to-door in Morwell to check how residents are coping.

Authorities are adamant there is no risk to the public and say any plans to evacuate Morwell are a long way from being put into action.

Victoria's chief health officer Rosemary Lester says an evacuation plan has been prepared, just in case.

"We've been keeping a very close eye on the carbon monoxide and that has not been a level of concern, which is good," she said.

But she was unable to say what would be considered as "long-term" exposure.

"That's something we're continuing to take advice from national and international experts," she said.

Crews had hoped to have fire out within a fortnight

Authorities this week repeatedly had hoped the coal mine fire would be extinguished within 10 to 12 days.

But the Fire Services Commissioner concedes it could take months.

"It's got the potential to be that. This is the best case scenario, 14 days," he said.

But hot and windy weather forecast for Wednesday and Thursday next week could set the firefighting effort back further.

About 200 firefighters have been battling the blaze since it started.

They have had to work short shifts because of the carbon monoxide in the area. So far 20 firefighters have been treated.

Locals consider possible class action against mine

Hundreds of locals are expected to go to a protest meeting in Morwell on Sunday, where they plan to gather evidence for a potential class action against the mine's owner.

Organiser Nerissa Albon says a social media campaign has attracted an enormous response and she is expecting a big turn-out.

Hot and windy weather forecast for next week could set the firefighting effort back further. ( ABC News )

"We're going to collect data to find out whose businesses are suffering and what are the health issues," she said.

"They're scared, they're starting to get annoyed now.... nobody can say when it's going to finish, it could go on for months," she said. "They would want compensation."

She has also invited the mine owners to attend Sunday's meeting, but has yet to receive any response.

Premier Napthine visited a health assessment centre in Morwell on Wednesday afternoon.

One of his MPs, Russell Northe, has hit out at a lack of information in the early stages of the crisis.

"If you ask me if the response was too slow, I have to agree with that because that's what the community is feeling," he said.

"Do we need to do more, absolutely we do."

There has been a mixed response from residents about the communication they are getting.

"I think we're being treated as gophers in the valley, mainly because there's no property lost," one man said.

Another resident believes authorities have done all they can.

"They're giving out information sheets, they've sent out voice-activated calls when the carbon monoxide was there," he said.

"I'm not sure what more they could do in the current circumstances."

Another local says authorities have a lot of explaining to do.

"I think that the people that are handling it, whether they be government or the fire brigade, have a lot to answer for," he said.

Commissioner Lapsley says he understands their frustration and, in some cases, their anger.

"We clearly have engaged with the community. Have we done enough? I'm sure there's someone out there saying no we haven't," he said. "We've got to keep at it."