Social distancing not needed in classrooms

And the prime minister says when students do return, the social distancing rules that apply to adult gatherings won't be necessary in classrooms.

There is mounting evidence to back the medical advice that children are less prone to catching and spreading COVID-19.

NSW Health has done a large study including testing children with no virus symptoms and found no evidence they were transmitting the disease.

"This is quite different from influenza, where we know they are sometimes super-spreaders and can spread the virus," chief medical officer Brendan Murphy told reporters on Friday.

"Most children who have contracted the virus in Australia have contracted it in the family home ... not contracted it in the school environment."

The nation's health officials continue to advise there is no reason for schools to close.

Despite this, the states and territories continue to take a range of approaches.

Some have encouraged students back to normal with the start of term two while others are offering mainly distance education for at least the next month.

The health advice says appropriate workplace safety measures should be taken to protect teachers, including cleaning door handles, desks, computers, hand-rails and playground equipment several times a day.

The advice also says classroom furniture should leave as much space between students as possible and children should be encouraged to keep 1.5m apart from others when entering classrooms or during break times.

Teachers are also told to keep 1.5m apart from each other in staff rooms.

But Prime Minister Scott Morrison emphasised there was no requirement for minimum floor space per person, unlike other in enclosed areas such as shops.

"The four square metre rule and the 1.5m distancing between students during classroom activities is not appropriate and not required. I can't be more clear than that," he told reporters.

However, unions have concerns the requirements around regular cleaning and making sure soap or hand sanitiser is freely available are not being met.

In a statement, the Australian Education Union said the social distancing guidelines "provide little clarity about how governments are going to ensure a safe working environment for teachers, principals and support staff".

"It is still not clear how governments expect schools to manage social distancing for adults. It is contradictory to have one set of rules for adults outside of the school gate and another inside," the union's federal president Correna Haythorpe said.

She called for a phased implementation of a return to normal business for schools.

Earlier, senior federal minister Peter Dutton told the Nine Network's Today show of the difficulties he was finding with having his teenage sons doing homeschooling.

"You've got to make sure they're not doing YouTube, they're not playing Fortnite, they're not texting their mates, not on Snapchat and at the same time, work. And it just doesn't happen," he said.

"Let's take out the sick children, let's take out the teachers who are over the age of 60, let's have an environment where kids can learn again."

Australian Associated Press