The potential for terrorist chemical attacks in Britain is a “huge concern” and fire brigades must be better prepared, the country’s most senior fire chief has warned.

Dany Cotton, who was recently appointed London Fire Brigade’s first female commissioner in its 150-year history, said she would be introducing better training and more practise drills for her teams in preparation for such an attack.

Speaking to the BBC, Ms Cotton said: “I think the chemical attack is a really big threat because it’s an unseen one. It’s something you do with a relatively small amount of chemical if you can find the means to disperse it.”

She said of her approach to the training: “It’s ensuring we are ready and prepared nationally to respond to that and respond quickly.”

The fire chief also suggested that education was needed to train members of the public on what to do in the event of a chemical attack, which could be deadly.

”The natural reaction would be if something happens to run away and go somewhere else. But that just spreads it, which is what the terrorist wants.

“It’s very important that people stay contained and allow the emergency services to help them and out and to deal with the situation.”

Her comments follow warnings from UK security minister Ben Wallace that Isis had planned to use chemical weapons in a mass casualty attack on Britain.

Mr Wallace said the terror group have “no moral objection” to using chemical weapons against populations including the UK, “and if they could, they would in this country”.

Responding to the concerns, Hamish de Bretton-Gordon, a former Army officer and chemical warfare expert, said such an attack may not kill many people, but would have a huge psychological impact.

He said chemical attacks were not limited to military grade chemical weapons, but could involve more readily available industrial gases such as chlorine, which could still create lasting damage.