The Victorian Fire Services Commissioner, Craig Lapsley, has put into words what people in the Latrobe Valley have been almost too scared to mention - that the Hazelwood coal mine fire could destabilise the Princes Freeway and homes on the southern edge of Morwell.

The open cut mine is a massive hole in the ground on the southern side of the freeway which snakes its way between the mine and homes in Morwell South.

There is a 400 metre gap between the mine and the freeway and little if any gap between the freeway and houses.

The fire has been burning along a three kilometre length of the mine's vertical walls, although half of that fire has been suppressed.

But authorities also say the fire has burnt between 10 and 15 metres into the wall towards the highway.

It has still got a long way to go to bridge that gap but any deterioration of an already-narrow buffer zone could be significant.

Firefighting is not like building a house.

You cannot predict how many bricks you will lay over the next day or so.

A week's work can be undone in one hot windy afternoon, but the authorities are adamant they will have this fire under control in about two weeks, extrapolating from their progress so far.

Three years ago flooding of the Morwell main drain caused a wall collapse in the same area of the mine.

It caused cracking in the Princes Freeway and properties at Morwell South.

The main artery between Melbourne and East Gippsland was cut for months as mine owners and the local council argie-bargied over responsibility.

Smoke, ash adds to misery for Morwell residents

Most of the angst about the mine fire to date has been over the thick pungent smoke pouring into Morwell and surrounding towns in the Latrobe Valley, sometimes reaching west to Warragul and beyond and east to Sale.

Morwellians have borne the brunt and to a greater extent the residents of Morwell South where the level of smoke and ash has been more than double that of their neighbours in Morwell East.

Their homes are coated in soot, the fruit and vegetable gardens filmed in oily residue and their lives permeated by the sulphurous smell of burning coal.

They are angry that the authorities were preoccupied with fighting the fire and forgot about their welfare in the early stages of the fire.

As the reality set in that the fire was going to be a marathon rather than a sprint, various agencies including the Health Department, EPA and Latrobe City Council started to respond to the cries of protest.

Some of the responses were more confusing than helpful.

Advisory notices were issued for people with medical conditions to retreat inside their houses when it became too smoky outside.

Community newsletters then advised people if their houses became too smoky to throw open their windows and let the fresh air in.

They are told if their health starts to suffer to leave town for a while and return when the air is clearer.

Particulate contamination concerns

Concerns were raised about the level of carbon monoxide in the air after the fire services confirmed about 20 fire fighters were sent to hospital with carbon monoxide poisoning in the first week of the incident.

At time visibility in Morwell is reduced to tens of metres.

More concerns were raised about the fine particles in the air causing horrendous visibility problems.

The small particles or PM 2.5 as they are more commonly known can be absorbed deep into the lungs.

They are smaller than 2.5 microns or two and a half millionths of a metre and are the element of smog and smoke that causes most health concerns.

Victoria's chief medical officer, Rosemary Lester has assured locals there is no long-term health threat from the smoke but even short term exposure can cause symptoms from an itchy throat to a heart attack depending on the individual's susceptibility.

The EPA has now announced, over two weeks after the start of the fire, that it would publish the PM 2.5 levels on its website.

It says the information has been collected since the start of the fire and passed on to the Health Department which then distilled the figures into appropriate health warnings.

The psychological effects are significant.

At times visibility is reduced to tens of metres.

No horizon is visible, sharp edges are blurred and every colour is filtered in a brown wash.

Threat to stability of mine adds to fire concerns

As the fire continues and people shift into the routine of their pale reality, more focus is turning to the long-term and possibly permanent threat to the stability of the mine.

Late last week a retired strategic planner and author from the Latrobe Valley, David Langmore, described the buffer between the mine and Morwell as disgracefully inadequate.

He has written a book, Planning Power, on the history of planning decisions in the region, particularly those affecting the 90-year-old power industry.

This week Commissioner Lapsley was the most forthcoming about the planning of the fire fight so far in an interview with ABC's Jon Faine.

A CFA strike team leader had rung ABC radio in Melbourne earlier claiming the fire fight was under-resourced and that fire quenching A-class foam wasn't being used to good effect.

The foam is a chemical cocktail that adheres to hydrocarbon compounds blocking off the air supply.

Commissioner Lapsley said neither was the case and the incident control team had even considered explosives to blow up the burning coal faces and stop the fire's penetration into the buffer.

But he said that dramatic alternative was discounted because of the risk of destabilising the coal face, the buffer, the Princes Freeway and even homes on the southern edge of town.

Fire fighters have had to limit their water use for the same reason.

As well as being combustible, brown coal is soft and permeable.

It already has a significant water content that sets it apart as an inferior substitute to the black coal New South Wales and Queensland.

And the effect of too much water has been more than adequately demonstrated by the closure of the Princes Freeway in 2011 and the collapse of the Yallourn coal mine after floods in June 2012.

In the early stages of the fire, a water main had to be installed because the disused section of the mine had no firefighting infrastructure and no fire prevention sprinklers to stop the initial bushfire spreading into the pit.

Firefighters have also pointed out that when the original bushfire was racing across the surrounding countryside toward the pit it jumped the Morwell River diversion alongside the mine, but there were no bridges or access points for the fire trucks to chase the fire front and head it off.

When quizzed on the issues, a spokesman for the mine owners, GDF Suez said the company had adhered to all the requirements of its fire management plan.

Commissioner Lapsley announced the arrival of a gadget from Tasmania that helped with the problem of too much water in the mine by using compressed air to apply the foam rather than water.

The news was welcome by sections of the community but some are asking why the equipment wasn't available in Victoria.

Some water is still being used but pumps at the bottom of the mine are being used to drain the surplus and prevent flooding

So the fire authorities and the State Government will continue to walk the tightrope between public anger and the need for caution.

People are worried they are not being told the full story and are not satisfied with the official messages.

The authorities continue to issue their health advice notifications for people to limit their physical activity and bit-by-bit more detailed information is being eked out on official websites.

The message from incident control is that there is no solution to the smoke problem until the fire is out and that is a process that cannot be rushed.