The Workplace Relations and Safety Minister says he will reveal what constitutes a high-risk workplace before Parliament finally passes new health and safety laws.
On Thursday the controversial Health and Safety Reform Bill passed its second reading 63 votes to 58, with Labour, the Greens and New Zealand First opposed.
The bill has been heavily criticised for going light on some employers by removing the requirement for small businesses, that are not deemed high-risk, to have elected health and safety representatives.
The Minister Michael Woodhouse said he would further clarify with high risk means before the bill's committee stages.
He said the law change would protect workers while not being unnecessarily onerous for businesses, and that shouldn't be any cause for concern.
Mr Woodhouse told Parliament some MPs and commentators had misrepresented the changes.
"The unnecessary anxiety that this has created. The changes to worker participation, balanced the needs of workers and businesses."
"The bill will allow for innovative and flexible practices while simplifying compliance for small business."
But Labour MP Iain Lees-Galloway said blatant and rampant fear-mongering at select committee had derailed the bill.
''The changes that have been made as a direct response to some of the most strident attacks on this legislation that were made at the select committee."
He said those came from a handful of fringe employers who did not value health and safety and who came from industries with some of the worst health and safety records.
Mr Lees-Galloway said it was appalling that small businesses could be excluded from having a health and safety representative, given they kill and maim more workers than large businesses.
The chair of the committee and National MP, Jonathan Young, said he regretted that the opposition now couldn't support the bill.
He said the intent and outcome of the bill would be a massive improvement in the health and safety in New Zealand.
His colleague, Maurice Williamson, told Parliament he was happy to take the blame for the changes.
"If Labour Party wants to have an evil demon beast to stick the skewer in, then put my name on that," he said.
"I was uncomfortable with this bill as introduced, as not having the right balance point."
But Labour's Sue Moroney said it was deplorable some MPs had forgotten the lessons learned by the Pike River mine disaster in 2010.
The bill is likely to come before the house for debate again in August.