The motorway fully reopened during the early hours of Saturday morning, about 20 hours after the original incident, which saw an emergency situation declared and a one-kilometre exclusion zone established.

Engineers from the Department of Transport and Main Roads inspected and gave the all-clear just after 4am, reopening the final southbound lane.

At the height of the delays, southbound traffic stretched back about 11 kilometres and northbound congestion was back five kilometres to Beenleigh, according to Australian Traffic Network reporter Olympia Kwitowski.

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.

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

The charred wreckage of the chemical truck was cleared from the motorway on Friday evening and traffic slowly started flowing, but police did warn of significant delays into the night.

Buses travelling in both directions along the motorway were running up to an hour late because of the disruption.

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.

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.

More than 30 firefighters were called to the scene to control the fire, which sent thick smoke blowing south towards commercial and residential areas.

With Amy Mitchell-Whittington and AAP