People in Napier are being urged to stay out of the Ahuriri Estuary after 1000 litres of hydochloric acid spilled onto a nearby street.
The Hawke's Bay Regional Council says the acid spilt onto Thames Street, and entered a stormwater system that flows into the estuary.
The council's pollution response team and Fire and Emergency are at the scene.
Anyone suffering symptoms they think may be related should contact Healthline on 0800 358 5453 or see their GP.