Hundreds of quarries could still be unregistered as a two-year window to register with WorkSafe ends.

Photo: Westpac Rescue

WorkSafe introduced new regulations in 2014, which gave quarries two years to register and update their safety standards.

It says those quarries that remain unregistered are now in line for a crack-down.

Between 2014 and 2015, four men were killed while working at quarries, with two of those at unregistered quarries.

A WorkSafe spokesperson said there could be up to 1200 sites nationwide which could meet the legal definition of a quarry or alluvial mine.

Figures released to RNZ showed 742 quarries had registered with WorkSafe, up from about 500 in December.

WorkSafe also required every quarry to have a certified manager on site.

Chief inspector of extractives Mark Pizey said WorkSafe had done a lot of work to educate the industry about registering before 1 September, so there were no excuses for mines to be operating without doing so.

"We made it clear to the industry that given the time they've had time to notify us of their manager and register on the database that anytime after September first it is likely enforcement action will be taken."

Mr Pizey said quarries could not argue they were unaware of the laws introduced in 2014.

"I think that argument is becoming thin. WorkSafe has been very proactive within the sector, explaining the requirements - we've had meetings and held conferences which were always well attended.

"The majority of quarry operators recognise things needed to be regulated and they're receptive to the changes made," Mr Pizey said.

The industry had an abysmal record over the last few years, he said.

"The work we're doing is to make sure the people managing these quarries are up to standard so we don't see similar statistics again."

Quarry deaths