Brewery ammonia leak
Five people were left hospitalised after a chemical leak at a brewery in Berkshire, that also caused a part of the M4 to be closed overnight.
The ammonia leak happened on Monday evening at the Scottish and Newcastle site in Reading.
Everyone on the site was accounted for although five people were taken to hospital suffering from inhaling ammonia.
Junction 11 of the M4 was closed for part of the evening while fire crews and a special chemical unit dealt with the leak which was caused by two leaking valves.
Acid rain
A Royal Berkshire Fire and Rescue spokeswoman said "Although the police had classified this as a major incident it was tackled efficiently.
"Ammonia is toxic and corrosive and is a gas at low temperatures.
"Initially there was concern about acid rain."
A police spokesman said the Health and Safety Executive was now investigating the leak.