Fifteen-month-old Darren Halliday, who had been walking for only a few weeks, died in the kitchen of his home in Blyth, Northumberland, at the weekend.
The Royal Society for the Prevention of Accidents said the incident underlined how easy it was for nappy bucket lids to be removed.
'Perhaps manufacturers could investigate making them more secure to prevent any further tragedies,' a society spokeswoman said. 'We have child-proof locks on cupboards and drawers, so why not nappy buckets?'
Darren had wandered into the kitchen as his father, also called Darren, 24, sat in the lounge and his mother, Sandie Brown, 21, was visiting a neighbour.
Ms Brown said: 'He had been told off before and earlier that day for playing with the bucket and throwing out the nappies.
'There was only a little water inside. We will never know exactly what happened but we think he must have reached in and fallen.' She added: 'I will never have another baby like him. I feel as though God just loaned him to me and has taken him back.'
His father found him in the water after to going to check when he could not hear any noise from the next room. He carried him out into the street and the next-door neighbour Simon Dale, 24, tried to revive the boy with the kiss of life and heart massage as his wife called an ambulance. But Darren was dead when he arrived at Wansbeck Hospital in Ashington.
His grandmother, Doreen Halliday, 66, said: 'This is a terrible tragedy, he was a little beauty. He was their only child and they loved him so much.'
Mr Dale described how he had tried to save the boy's life. 'Darren came running out of the house with the little lad over his shoulder and ran across to a neighbour's house.
'He said the baby had stopped breathing, so I told my wife to call an ambulance and gave him heart massage and the kiss of life.
'I have never done it before but Sandie was running about shouting hysterically for someone to save her baby.
'He began breathing again and seemed to be bringing up some of the water. I went to wait for the ambulance outside but he didn't pull through.'
Northumbria Police said there were no suspicious circumstances.Reuse content