The Department of Environment and Science is investigating after Queensland Alumina released a caustic spray of chemical following an equipment failure in Gladstone, central Queensland.

The department said overnight on Tuesday, a high-pressure pipe carrying sodium hydroxide had failed, with the chemical spray released onsite, as well as onto neighbouring areas.

Queensland Minister for Manufacturing and Member for Gladstone Glenn Butcher said the refinery has a well-trained emergency response team that shuts down valves, and while the pipes are tested "meticulously" the product is so abrasive that pin holes in parts of the pipes or pumps can occur.

"From what I'm led to believe, it was on Unit One, which is the closest to the Gladstone community.

Queensland Alumina Limited said it was reviewing the extent of the spray, but it believed impacts were localised.

No-one was injured and a company investigation was underway to understand the cause of the incident.

"The equipment was quickly isolated, and the release contained," Queensland Alumina said.

"Alkali in low concentrations does not have the potential to cause health effects."

Toolooa resident Jennifer Dekker's car was covered in the spray.

She said she wanted more information on possible health impacts and was concerned about her children and dog using her backyard.

"It was like snow all over our cars," Ms Decker said.

"If it's eating my bonnet and making my bonnet bubble, if it eats away at steel what's it going to do to our health?"

Ms Decker said she had lived close to the refinery for years, but this is the first time an incident like this had happened.

Community can claim

Mr Butcher said Queensland Alumina will send out letters to affected people, including with insurance details on how to claim costs with the company and stop further damage.

"When an event like this happens … they put in pads around certain locations around Gladstone which gives them an idea of how far the events spread," he said.

"People around that area they'll likely see just small, really fine speckles on those types of things.

Mr Butcher said he believes there is no respiratory risk to the community and incidents like this are "extremely rare."