An effort is underway to identify illegal quarries, after four deaths on the job last year - two of them at unregistered sites.
Around 400 quarries are currently registered throughout the country, but WorkSafe believes there may be up to 800 others operating illegally.
WorkSafe's chief inspector of extractives, Tony Forster, says basic safety requirements need to be met.
"This is about guarding, this is about ensuring that fences are in place, this is about ensuring that people operate heavy machinery in a safe and responsible way."
He says WorkSafe is working hard to change the culture in the industry.
"If people are taking these massive pieces of earth-moving equipment out you would expect them to have basic training, you would expect people to understand how to operate. That's what we would expect from haulage operators on the road, we'd expect that in shipping companies and anyone else in any other walk of life."
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