Workplace Relations and Safety Minister Michael Woodhouse says health and safety changes won't stop kids from climbing trees at school.

Some big law changes take effect on Friday - and a few more on Monday - which you really ought to know about.

All right, give me the skinny.

It is hard to know where to start because the changes are numerous.

Probably most significant is a $25 increase in benefits for families with children. There will also be extra money for low income families via in-work tax credits as well an increase in the rate of childcare assistance from $4 to $5 per hour.

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Paid parental leave will increase by two weeks to 18 weeks.

Anything else?

Yes, the list goes on. The minimum wage will rise from $14.75 an hour to $15.25, ACC levies will fall by $232 million and superannuation will increase by 2.7 per cent.

Great! More money!

Not so fast.

Beneficiaries will be expected to work 20 hours part-time instead of 15 in order to keep the same allowances. Sole parents will have to get back into part-time when their child turns 3 instead of the current 5 years old.

And the law changes?

Zero hour contracts, which meant no guaranteed hours for some workers, will become illegal.

The biggie is the Health and Safety at Work Act, which takes effect on Monday.

Health and safety you say? That's my favourite subject!

Really? Wow. In that case, you will be interested to know Worksafe is more likely to prosecute employers as a result of the law. Workers will also have obligations though so everyone will need to be on top of what's expected.

The new law requires employers to take "reasonably practicable" steps to manage health and safety risks at work. It also means company directors need to be more hands-on about health and safety and all businesses need make sure staff are well-involved in such things.

What about all this talk about schools having to ban kids from climbing trees because of the changes?

It depends who you're talking to.

Workplace Relations and Safety Minister Michael Woodhouse says not only is it possible for kids to continue climbing trees but he "actively encourages" it. Both Worksafe and the Ministry of Education have provided advice to schools on what "reasonably practicable" steps means for them.

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