The improper use of a Bumbo baby seat led to the death of a six-month-old boy in Perth in 2013, an inquest has heard.
The infant was placed in the seat under a running shower by his mother who would usually have accompanied him, but she left him alone for a few minutes as she was unwell and exhausted after trying to settle the restless child during hot summer nights in January 2013.
He fell out of the seat, which had moved to a position that blocked the drain, filling the cubicle with water, and she returned to find him not breathing.
He died three days later in hospital, with a forensic pathologist later concluding the boy had died from bronchopneumonia and hypoxic brain injury after nearly drowning.
The West Australian Coroner's Court heard on Tuesday that the voluntary worldwide recall of four million of the foam seats was announced in August 2012, and a free restraint belt was offered via Bumbo South Africa's website, where new safety guidance was available.
The court heard the six-month-old's seat had no restraints or harness fitted, while a warning sign on the rear instructed parents to never use the Bumbo on a raised surface, or as a car seat or a bath seat.
Counsel assisting the coroner Lyle Housiaux estimated that of about 950 new and used seats recently listed for sale in Australia on an online trading website, roughly half did not include the retrofit safety harness.
"Kidsafe WA advises that all children should be closely supervised, within arm's length, when in any water including when using bathrooms," Mr Housiaux said.
"They report that it only takes a few seconds in 5cm of water for a child to drown."
WA Police forensic officer Michael Jeffrey Lamb said a test of the 20 centimetre-high shower recess showed it filled to overflowing within about seven minutes.
Investigating officer Sarah Long told the court the tragic accident would not have happened if product use recommendations had been followed.