CLEAR, the Campaign for Lead Free Air, was started in 1981 when a wealthy property developer, Godfrey Bradman, recruited the veteran campaigner and former Director of Shelter, Des Wilson to get lead-free petrol into the United Kingdom. Wilson ran the public campaign and co-opted Dr Robin Russell-Jones as the unpaid medical and scientific advisor. In April 1983, the Royal Commission on Environmental Pollution (RCEP) published a report that confirmed the dangers of lead to children's health, and recommended that lead should not be added to petrol. Within half an hour of the RCEP report being published, the Environment Secretary, Tom King, announced that the government would support the introduction of unleaded petrol, that oil companies would have to provide it on forecourts, and that car manufacturers would have to make engines that could use it. Shortly after, Wilson resigned from CLEAR to become Chairman of Friends of the Earth. From 1984-89 Russell-Jones became Chair of CLEAR whom he represented on the Government committee, Working Party on Lead in Petrol (WOPLIP). Having achieved its objectives, CLEAR was officially closed down in 1989. Due to the campaign's significance, the Wellcome Library, one of the world's major resources for the study of medical history, holds a collection of CLEAR's archives. CLEAR is regarded as a textbook example of how to run and win an environmental campaign. Although the services of an experienced and charismatic campaigner (Wilson) was crucial to the success of CLEAR, it would never have achieved its goals without a solid scientific base. Ultimately it depended upon a junior hospital doctor (Russell-Jones) and a respected scientist (Robert Stephens) with sufficient confidence in their own judgement to risk their professional reputations in pursuit of a cause. When CLEAR was launched, the blood lead level regarded as safe by the medical profession in the UK was 35 microgrammes per decilitre of blood. In 1991, the level deemed safe by the US Centre for Disease Control (CDC) was lowered to 10, but CDC now accept that there is no safe threshold and define a level above 5 as a cause for concern. Background Tetraethyl lead was first added to gasoline in the 1920s as an “anti-knock” agent, which is a cheap method of boosting the octane rating. It is not possible to use catalytic converters with leaded fuel as the lead coats the platinum and renders the catalyst ineffective. Lead free gasoline was therefore