Two of three investigations initiated at Mackay Sugar this year have been completed.
The first investigation followed a boiler explosion at Marian Mill on May 24 and revealed a number of failures, rather than a single factor, had contributed to the incident.
Mr Doolan said the details would not be made public but measures were being taken to ensure it would not happen again.
A second investigation was launched after a Marian Mill worker was burnt by hot vapours from a tank vent on June 3.
He was not seriously injured.
But work was under way to turn the vent that shot the hot vapours towards the floor, to ensure no other worker was burnt in the future.
And last Tuesday a Mackay Sugar cane train was involved in a collision with a tractor on a private Homebush property.
An investigation into the incident is still under way.