Here are some tips on how they can wear masks safely and effectively.

Students in year 7 and above and all staff will be required to wear masks at school while children in year 3 to 6 will be encouraged to wear them at the discretion of their parents.

Younger children from preschool to year 2 are not encouraged to wear masks because they can be a choking hazard and often worn incorrectly.

Exceptions will be made for children with disabilities that make it difficult for them to wear masks.

University of Canberra Professor of microbiology Reena Ghidyal said the design of the mask does not matter so much as long as it fits properly.

"A mask should be such that it covers your nose, your mouth, and it's just under your chin at the other end. And it's not moving up and down as you move around doing whatever you're doing," she said.

Fabric masks protect other people in case the wearer is unknowingly infected with the virus. Disposable medical masks protect the wearer as well as the people around them.

Masks should not have vents or exhalation valves because it lets unfiltered breath escape the mask.

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The World Health Organisation (WHO) recommends that children with underlying health conditions such as cystic fibrosis, cancer or immunosuppression should wear a medical mask, in consultation with their doctors.

A fabric mask should have three layers of fabric, according to WHO. The inner layer should be absorbent material such as cotton. The middle layer should be a non-woven, non-absorbent material such as polypropylene. The outer layer should be non-absorbent material such as polyester or polyester blend.

Disposable medical masks can be purchased in smaller sizes. Schools will have a supply of masks in case students need them but they will be expected to arrive at school wearing a mask.

Good hygiene is important in wearing a mask effectively.

"Remember that when we put our masks on, and take them off we have to be very careful that you're not touching the actual surface of the mask," Professor Ghidyal said.

"Every time you take it off, you have to do the full hand wash, the WHO recommended washing for minimum 20 seconds with hand sanitiser or 40 seconds with soap and water, and you have to do that when you take it off, and before you put it on."

All schools will be stocked up with hand sanitiser and soap however it might be a good idea add some hand sanitiser to their school bag.

READ MORE: How to wear a mask without your glasses fogging up

Masks are ineffective if they become damp so if the wearer becomes sweaty they will need to change it more often.

Disposable masks need to be changed every four hours. They should be put straight into the bin after use.

Again, hand rub or hand wash is required before putting the mask back on. Do not touch the surface of the mask when taking it off, hold it by the ties or elastic.

Wash and dry fabric masks completely between uses. Students should bring a couple of masks in case they need to change throughout the day.

Students will need to wear a mask all day except for when they are eating or drinking, doing vigorous exercise, when outside alone or during an emergency.

They can take off masks when communicating with a person who is hard of hearing.

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If doing a formal exam, students need to wear a mask to the exam room but can remove it when seated at their desk.

If you do take a mask off for a certain activity, Professor Ghidyal said it needs to go in a clean bag where it will not be in contact with other masks.

Children won't follow all of these guidelines all of the time, but mask do work as part of a suite of safety measures.

"It's really amazing what that little shield can do because it stops people touching their face ... because we do that without even thinking and then we transmit disease.

"Having that mask makes a big difference... even if people don't use it absolutely 100 per cent in the way it should be."

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