Ahead of the summer party season, Victoria's Worksafe issued the warning after conducting 380 inspections at 44 events and theme parks.
Two Melbourne schools were busted for unsafe setups in October, including a jumping castle that wasn't held down, unprotected electrical equipment and an inflatable ride set up beneath power lines.
So far this year, inspectors have dished out 41 improvement notices and ordered the immediate fix of 44 safety issues.
Improper anchoring is one of the common errors made when setting up inflatables. (Jennifer Chapman/AAP PHOTOS)
Common issues were improper anchoring of the inflatables, lack of weather protection or guarding of electrical blowers, and inadequate supervision.
Worksafe also warned providers against dropping off the attractions and leaving it to inexperienced customers to set up and operate the equipment.
"Well-meaning parents and volunteers organising events on a tight budget may be tempted to choose a cheaper, less professional amusement hire option, but backyard operators just aren't worth the risk," WorkSafe executive director of health and safety Sam Jenkin said.
"No one wants celebration to turn to tragedy."
Six children died in Tasmania in 2021 when the bouncy castle they were playing on became airborne at an end-of-year celebration at their primary school.
Rules around such amusements were updated in Tasmania and NSW in 2022 and in February in Queensland.
11°C