Two people who inadvertently created toxic chlorine gas sparked an emergency “chemical incident” in Falmouth yesterday afternoon.

Crews from four fire stations across Cornwall joined paramedics in Oakfield Road just after 3pm, where a woman had been taken ill and a second person was also suffering the effects of breathing in chemical fumes.

It transpired that they had mixed chemicals together that had produced the poisonous gas, which was used by the German army as a major new weapon in World War One.

Firefighters from Truro and Tolvaddon, backed up by a support vehicle crew from St Just and the Environment Support Vehicle team from Penzance, were forced to wear special breathing equipment as they entered the house, to find and identify the chemicals that had been mixed.

These were then taken outside and the house was ventilated, while the two casualties were taken to the Royal Cornwall Hospital in Truro for tests.

Describing it as a "chemical incident," a spokesperson for Cornwall Fire and Rescue Service said: “After thorough investigation it was confirmed that the gas produced was chlorine.”

When breathed in, chlorine gas can make breathing difficult and result in a cough, along with sneezing and irritation to a person’s nose and throat.