He picked up the bucket and put it out of harm's way around the back of the property and then supported the man until the arrival of St John paramedics.
A nearby neighbour who was also first to the scene said she heard loud bangs come from the property and a man yelling, "Ring the ambulance!"
"I just heard this pop, pop, like gunshots." she said.
"So I ran over to the back of his house and he was covering his face. I just grabbed the hose and tried to rinse his face"
EARLIER: A person has been injured while mixing pool chemicals in Maungatapu.
Emergency services have been called to chemical explosion at a property in Taipari Street, Maungatapu
A Northern Fire Service communications centre spokesperson said the initial report which came from ambulance staff was that someone was working with swimming pool chemicals when the substance exploded.
There are reports of burns to an occupant's face.