"Several explosions" were heard from hundreds of metres away and an emergency situation declared after a gas tanker carrying hydrochloric acid burst into flames on the Pacific Motorway.

The motorway was closed near the Logan Hyperdome after a southbound Coogee Chemicals truck carrying 15,000 litres of hydrochloric acid burst into flames and billowed "large volumes of black smoke" about 8.40am on Friday.

Police revoked the emergency situation at 4.50pm, with northbound lanes and two southbound lanes of the Pacific Motorway reopened.

One of the southbound lanes remained closed, and police warned commuters could still expect traffic delays for some time.

The emergency area had covered the northbound and southbound lanes and a one-kilometre radius of the crash site.

Emergency services and Coogee Chemicals staff decanted the acid from the burnt tanker to another truck before the damaged vehicle was removed from the road.

Police said the southbound lanes should reopen by 5.15pm but warned motorists to expect lengthy delays into the evening.

A witness to the explosion told 7 News he saw the truck driver leap from the cab as it erupted in flames.

"The cab was on fire and he has literally opened up the door and just bolted ... it went up way too quick," the man said.

Coogee Chemicals confirmed the driver had been checked for smoke inhalation and had been released.

Queensland Ambulance Service clinical support officer Ross Hodges spoke with the truck driver and said it was very lucky nobody was injured in the explosion.

"The truck driver did very well, he recognised the situation was quite serious early on, managed to have the foresight to pull over onto the side of the M1," he said.

"(He) managed to call the emergency services very quickly and also flag down passing motorists to get them to come to a standstill.

"(He said) the fire appeared to be coming from under his cab somewhere but he was unsure at the time of the exact cause of the fire."

Tolls were suspended from 10.45am in both directions at the eastern end of the Logan Motorway and the southern end of the Gateway Extension Motorway to provide an alternative route for motorists, according to Go Via Network's website.

Tolling was expected to resume about 6pm once the accident had been cleared and diversions removed.

Police urged nearby businesses to evacuate, people nearby to remain inside and those with breathing difficulties to have medication or breathing aids nearby.

More than 30 firefighters on scene controlled the fire just before 10am and the northbound lanes at Loganholme reopened just after 11am.

An emergency services spokesman said the smoke was blowing south towards commercial and residential areas and was "likely to affect the air" for a large part of the day.

Several explosions could be heard about 600 metres away from the incident at Andy's Auto Rentals, manager Wayne Garner said.

"I was putting a customer out into a 12-seater bus and the next minute we heard little boom explosions in the distance and a lot of smoke," he said.

"We heard around seven explosions and the flames were quite high.

"I thought it was one of those small trucks that carries the gas bottles for barbecues, because it was repeated explosions."

In a statement, Coogee Chemicals said: "The company is relieved that no one has been injured in the incident but is concerned about disruption or distress to local residents, businesses and passersby."

The national company, with its head office is in Western Australia, manufactures and imports agricultural, mining and industrial chemicals for both the Australian and international markets.

Police said moving the burnt tanker was going to be a "logistical challenge".

Emergency services and Coogee Chemicals officers were preparing to remove the hydrochloric acid from the damaged truck and transfer it to another tanker, estimated to take about an hour.

The damaged truck will then be removed from the site under police escort.

Scientific officers from the Queensland Fire and Emergency Services were on scene.

Meanwhile an earlier multi-vehicle crash along the Pacific Motorway at Macgregor had been cleared, police said.

Paramedics were called to the crash near the Kessels Road on-ramp that blocked right and left lanes on the northbound lanes about 7.30am.

No one was injured and the area was cleared by 8.15am.

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