MINING company Anglo Coal has pleaded guilty to failing its safety obligations and causing the death of electrician Paul McGuire at its Grasstree mine.

Prosecutor Ruth O'Gorman said in the Mackay Magistrates Court that on May 6, 2014, Mr McGuire, 36, went to a location at the mine to work on a gas sensor.

That area was a 'goaf' - a part of the mine where coal had already been extracted that had been sealed.

Ms O'Gorman explained that in goafs, the air became irrespirable and fatal.

She said that at 1.05pm, Mr Guire opened the hatch to the goaf, breathed in the air and died almost instantly.

Ms O'Gorman provided six victim impact statements from Mr McGuire's family, who were seated in the public gallery.

He had a wife, two daughters, parents and brothers, Ms O'Gorman said. They were suffering from an "ongoing sense of loss".

Ms O'Gorman said the maximum penalty for the offence was $550,000. She said a fine of $100,000 was warranted, and that the parties had agreed that Anglo pay $15,000 in investigation costs.

She said that the gas sensor Mr McGuire was asked to maintain had been moved away from the area on January 14, 2014. Between February 4 and April 1 three job cards were issued instructing an electrician to go to the old, incorrect location.

Defence barrister Geraldine Dann said Anglo accepted that the failure wasn't a one off, that it was a serious offence and an ongoing tragedy to the family.

She said the company had met funeral, travel and accommodation costs and were giving Mr McGuire's children a scholarship.

Ms Dann said the hatch had been secured by a nut and bolt, and its physical appearance would have indicated to a miner that it was the entry to a goaf.

On questioning from Magistrate Damien Dwyer, Ms Dann said the company could not determine whether 'no road tape' was up in the area.

She said Mr McGuire had been acting in accordance with what the job card dictated.

Ms Dann said Anglo had taken significant steps since the incident.

Those included that it is now a requirement for electricians to be accompanied by a deputy for such jobs and that on each shift deputies inspect areas to ensure 'no road tape' is in place.

The prosecutor dropped a second charge against Anglo of failing to discharge safety obligations and two counts of failing to discharge safety obligations against manager Adam Garde.

Magistrate Damien Dwyer adjourned the sentence to November.