Spanish authorities have told more than 160,000 people near Barcelona to stay indoors after a fire at an industrial warehouse released a toxic cloud of chlorine over a wide area.
The blaze, in the coastal city of Vilanova i la Geltrú, south of Barcelona, started at dawn on Saturday in a warehouse storing pool cleaning products, the regional fire service said.
“If you are in the zone that is affected do not leave your home or your place of work,” the Civil Protection Service said on social media.
How can “indoors” save you from chlorine gas?
There is minimal air exchange between the indoors and outdoors when all the windows and doors are closed. There is still some, because obviously you can stay in a building even without HVAC for a long time. But it’s slow enough that something as reactive as chlorine gas will react with other materials before it reaches you.