MPs have been told that check inspectors should be used in all types of quarrying and tunnelling.
Parliament's Transport and Industrial Relations Select Committee has been hearing submissions on a bill to implement health and safety changes following the Royal Commission into the Pike River mine tragedy in which 29 men were killed in 2010.
The legislation strengthens mining regulations; its provisions include the regular inspections of mines and some quarrying operations that are large and complex.
Some submitters have argued that check inspectors should be used for mines only where methane is a risk, but Ray Bianchi of the Northern Amalgamated Workers Union says tunnelling and quarrying are very risky operations.
"Well, for God's sake, they blow up mountains - they blow 'em up!" he told the committee on Thursday morning. "And when they come down, our members have to put that stuff onto trucks - and it's all loose at this stage, so it's a very, very unstable situation. To say it's not hazardous is ridiculous."
Mr Bianchi also spoke out against those who have suggested workers should not have too much influence over managing safety in the workplace, saying that work sites are safer when unions and their members are involved.
The national secretary of the Engineering, Printing and Manufacturing Union, Bill Newson, told the committee that workers at Pike River mine didn't have the ability to ensure their safety and workers need to have more say.
"The whole point of the Royal Commission's recommendation is that industry health and safety representatives provide and extra set of eyes and ears that are independent of the employer, independently funded, transparent and accountable."