Five hundred litres of highly corrosive liquid caustic soda was spilled after a forklift pierced a container at a Napier transport depot yesterday.

Fire Service crews wearing protective equipment neutralised the spill with citric acid, assistant area commander Alan Bamber said.

Crews from Napier and Hastings responded to the incident at Hooker Pacific Transport, on Edmundson St, Onekawa, at 11.45am.

Mr Bamber said the staff on site had responded well and were able to contain most of the liquid on the premises. No one was hurt.

"The people at the premises dealt with it very well in the initial stages," he said.

It took about two hours to ensure the spill had been neutralised and the site made safe.

"Once the caustic soda is neutralised by the acid it's then cleaned up by the owner in conjunction with advice from the regional and local authorities," Mr Bamber said.

Fire crews were decontaminated using high-pressure showers after the incident.

Hawke's Bay Regional Council environmental officer Phil Hall said the spill occurred when a 1000-litre container was pierced with a forklift, allowing about 500 litres to escape.

"It was really a case of making sure that it wasn't going to go into stormwater off the site, which it didn't," he said.

Hooker Pacific branch manager Peter Hynes said the caustic soda was being transported for a firm which used it as a cleaning product, and was "not a highly dangerous substance in that concentration".

He was happy with the staff response, but said the incident would be reviewed.

"We have processes in place and all of those were followed."

Napier City Council and Department of Labour staff were also on site to oversee the clean-up.

Caustic soda, or sodium hydroxide, is corrosive and contact with skin can cause severe burns.