Thousands in Spain confined indoors for hours by toxic fumes
The blaze, in the coastal city of Vilanova i la Geltru just south of Barcelona, started at dawn on Saturday in a warehouse storing pool cleaning products, the regional fire service said.
Civil protection services instructed people to stay inside and close the windows, before lifting the restrictions around noon.
"The lockdown is being lifted," Catalonia's interior minister, Nuria Parlon, announced at a press conference just after 12:15 pm (1015 GMT).
Because some harmful particles could remain in the air, he urged children and those with health conditions to remain indoors, and cautioned against exercising outdoors for the moment.
Firefighters also urged residents to remain alert, saying that new shelter-in-place orders might be announced in specific areas, depending on the winds and the movement of the toxic cloud.
The at-risk area stretched across five local districts along the coast, from Vilanova i la Geltru to the village of Calafell, near Tarragona.
"No casualties" were reported, the fire service said on X on Saturday morning, adding that it had deployed a large number of units to bring the fire under control.
It said it was "monitoring the column (of gas) caused by the blaze for changes and for its toxic levels".
The authorities closed roads in the area and shut train stations to prevent people approaching the affected area.
"It is very difficult for chlorine to catch fire but when it does so it is very hard to put it out," warehouse owner Jorge Vinuales Alonso told local radio station Rac1.
He said the cause of the fire might have been a lithium battery.
Vilanova mayor Juan Luis Ruiz Lopez told public television TVE that authorities expected that, with the fire being put out, "this toxic cloud will start to dissipate and we can lift the measures currently imposed".