Inflatable and portable children's pools may be required to be sold with compulsory fencing to prevent backyard drownings, with some experts even floating the idea of a ban.

A draft paper by a Westmead Children's Hospital pool safety group warns portable pools are "more dangerous than permanent pools" because many parents perceive them as less risky.

"The injury to young children caused by unfenced portable pools is too great a price to pay," said a draft report by the swimming pool safety working group.

In addition to fencing and more public education, it also suggested a ban as another way of preventing drownings and near-drownings in the 110,000 portable pools sold annually.

The chair of the group, Professor Danny Cass, ruled out a ban on Saturday.

He described the paper obtained by Fairfax Media as a "draft of a draft". It was mistakenly circulated to the swimming pool industry last week.

The finished paper will form part of the hospital's submission to a major review of pool fencing being conducted by former Treasury secretary Michael Lambert.

Professor Cass said his experience was that working with industry on previous safety issues like baby walkers, trampolines and skateboards had avoided the need for regulation.

Professor Cass, who is the director of trauma at the hospital, envisaged the preferred option would be requiring portable pools to be sold with a fence, something similar to the inbuilt fencing that now surrounds trampolines.

"There is nothing that engineering can't fix," he said.

The draft discussion paper estimated that there are as many as 10 incidents classified as "non-fatal drownings" in portable pools a year. Health experts in the United States had noted a rise of drownings and near-drownings in unfenced portable pools of as much as 25 per cent.

Because of increased awareness of the risks associated with non-fatal drowning, more parents and ambulances were sending children who had suffered a non-fatal drowning to hospital for treatment.

Professor Cass said only 5 per cent of these children would suffer permanent and serious injury. The hospital was also beginning to track children who appeared to have fully recovered after the incident. In some cases, these children had minor concentration and behavioural problems that the hospital was studying.

Under existing pool guidelines, all pools that are capable of being filled with more than 300 millimetres of water (about the depth of the average ruler) must be surrounded by a four-sided fence, with a height of 1.2 metres above the ground. Yet many parents are unaware that portable pools also need fencing.

Professor Peter Middleton, the chair of the NSW Branch of the  Australian Resuscitation Council, said the problem with many portable and inflatable pools was that they had low sides, making them easy for kids to access.

"These pools are real danger, and we wouldn't leave kids in a full bath of water by themselves, or even in the same room, but some parents leave them in a bath full of water in the garden."

He said the fatality statistics hide a problem: the children who don't die from drowning but who are left with brain damage.

Brian Owler, the president of the Australian Medical Association, said parents often had a false sense of security with portable pools because they were so easy to buy.

"People think it is just a portable pool, kids can't drown in them, and people don't pay as much attention as they do to properly installed pools," said Dr Owler.

The head of the Swimming Pool and Spa Association of NSW, Spiros Dassakis – a member of the working party – declined to comment until his organisation had finalised a response.

Professor Cass said nothing should overshadow the primary safety messages, which was "supervision, supervision and supervision", the need for a gate and the importance of CPR.

He estimated that of all drownings, including those that were non-fatal, as many as half were caused by a lack of parental supervision.

Professor Cass suggested a slip-and-slide might be a safer and healthier way to cool off next summer.

"Everyone is starting to come on board, and realise that maybe a bit of plastic and a hose, and have the kids slide along, might be a little better than a plastic thing that gets algae and causes middle-ear infections or worse."