A small explosion caused a leak in a drum of hydrogen peroxide this morning at a commercial laundry, the Fire Service says.
Staff at Pryors Apparelmaster in South Auckland were evacuated after a drum of hydrogen peroxide began "bubbling".
Fumes from the 200-litre container filled the premises on Takanini School Rd, prompting an emergency callout.
Eight fire trucks and a hazmat vehicle were on the scene said Fire service senior station officer Tony Searle.
"We got advice from chemical engineers and we decided to flush the chemical into the sewer system which is standard practice," he said.
Searle said the explosion was not caused through negligence. It was the first time they have been called out by the company.
Bystander Marcus Bodenstein waited two hours before going to work on the road.
"I didn't notice any smell or see any fumes. It looks like the firemen did a good job. It's just a pain having to wait to get to work. I'm supposed to be working on the road at the intersection nearby."
Police had closed roads close to the premises and cordoned off the corners of Takanini School Rd and Rangi Rd, Porchester Rd and Popes Rd, and Spartan Rd and Takanini School Rd.
Staff in surrounding buildings have returned to work however, staff at the laundry factory have not returned to their building.
Hydrogen peroxide is commonly used as a bleaching agent or disinfectant.