A HIGHLY toxic chemical – so strong that it can eat through road surfaces and solid steel – is being used to add fluoride to our drinking water.

Hexafluorosilicic acid is the concentrated form of the chemical which the North Cumbria Health Authority insists should be added in low concentrations.

Objectors to the policy, including Copeland Council, feel a mass experiment into potential side effects is being conducted on local residents.

The UK Councils Against Fluoridation (CAF), to which Copeland Council subscribes, say that Hexafluorosilicic acid is being transported along the M6 through Lancashire and Cumbria and on to the A66, near Penrith, bound for United Utilities water treatment works in Ennerdale and Cornhow. Here the chemical is added to water supplies for both Copeland and Allerdale.

Joint chairman of the UKCAF Professor John Whitelegg said the highly corrosive substance was used in the fluoridisation of drinking water, a process that aims to reduce tooth decay.

But Prof Whitelegg is a specialist in the risks surrounding the transportation of dangerous chemicals said the “inherent risk” of tankers regularly carrying the lethal chemical along the busy M6 and the winding A66 west of the motorway was not justified.

Prof Whitelegg said it was “bonkers” that such a volatile chemical was being transported to water treatment plants when the alternatives to reducing tooth decay, such as better education among children, were much safer.

He said: “Cumbria’s roads are “vertically challenged” and, no matter how safe the tankers are, accidents still happen. This is really asking for trouble.”

George Glasser, of the National Pure Water Association, which is working alongside UKCAF in delivering leaflets to residents along the stretch of the A66 warning them of the potential dangers, said the liquid had the potential to kill if it was to leak from a tanker.

“It is one of the most poisonous acids in the world,” said the environmental writer, who has investigated spills involving the substance in the United States. “Exposure to the skin and the subsequent chemical burn can lead to a heart attack within 24 hours, if not treated properly and inhaling the fumes from it dissolves lung tissue.”

He highlighted a spill in Phoenix, Arizona, that left 16 people needing hospital treatment and led to almost 10,000 people being ordered to stay indoors as an example of the severity of the acid escaping.

United Utilities said that the number of tankers carrying the acid to its site had not increased in recent years.

A spokesman said that all contractors employed by the company complied with strict legislation on the transportation of volatile and hazardous substances. “We pick them (contractors) on their safety record,” she said.

The Environment Agency said that it gave the fire service advice on how to deal with certain chemicals to prevent them harming humans and the wider environment.

Cumbria Police spokesman, Greg Stephenson, added that officers were well briefed on how to deal with such spills and would use binoculars at first to ascertain the nature of the chemical before immediately descending on to the scene.