A fire at the Shell Chemicals factory in the Hutt Valley has forced the temporary closure of the plant.
The insulation around pipes leading to a melting vat caught fire at about midday on Thursday, but the factory sustained little damage and is expected to be operating again in the next couple of days.
Shell says it will begin an investigation into what caused the fire on Friday.
A regional health official says factory staff were evacuated, but smoke from the fire did not threaten the public.
