Businesses with fewer than 20 workers will not now need health and safety reps, however those that are deemed high risk will, regardless of size.
Forestry and logging industries will be considered high risk, the Government has confirmed, but is still to work out other areas.
Labour has asked whether farming will be defined as high risk, and has also pushed for workers to have the right to health and safety representatives.
That would have been guaranteed under the Bill as originally put forward, and was supported by a task force, including employers, which reviewed health and safety laws in the wake of the deaths of 29 men in the Pike River mining disaster.
Sonya Rockhouse, who lost her son Ben, 21 in the mine, and Anna Osborne, whose husband Milton died in the disaster, watched today's second reading from the public gallery.
Labour's spokesman for labour issues, Iain Lees-Galloway, said the changes betrayed the Pike River families.
"The minister cannot tell us is what will be a high risk business...a bit like the TPP the Government is saying, 'trust us - we will get this right'.
"Well, the families of the Pike River 29 trusted the Government to listen to the recommendations of the Royal Commission and implement them. And the Government has failed to live up to the trust that was expected of them."
Employer groups are split over the changes: the Employers and Manufacturers' Northern support the original plan for universal entitlement; Business New Zealand has welcomed the changes on behalf of small businesses.
Workplace Relations and Safety Minister Michael Woodhouse said the legislation would protect workers while not being unnecessarily onerous for businesses.
"The Bill will allow for innovative and flexible practices, while simplifying compliance for small business in low risk sectors, where more formal approaches may not necessarily result in better health and safety outcomes.
"Let me be clear...small businesses will still have a requirement for worker engagement and participation."
Mr Woodhouse said he expected to be able to reveal what sectors would be high risk "quite quickly", and before the Committee of the whole House.
While the Bill was before select committee Prime Minister John Key denied that back bench MP Mr Williamson was planning to vote against the changes unless concessions were made.
In today's reading Mr Williamson said that if Labour was looking for an "evil demon beast", he was happy to have that label as he had been involved in the push to alter it.
"Everything in life has a risk associated with it...I was Minister of Transport for a number of years and I know I could have brought the road toll to zero by just making the speed limit 5km/h and only having self lane track armour-plated vehicles.
"The economy would have been bankrupt within a day...but I could have held my hand on my heart and said, 'We have had no deaths'. It is about balance."
Green Party MP Kevin Hague said the party was pleased with the original Bill, but the "Government has once again caved" to pressure from bad employers.
NZ First MP Clayton Mitchell said the party could not support the Bill because of concerns about what it saw as unintended consequences including extra cost on small and medium businesses.
