Thomas Midgley Jr.

Midgley synthesised the first CFCs to replace refrigerants that were then toxic or flammable, and publicly demonstrated their low acute toxicity. In 1974, thirty years after his death, Rowland and Molina showed that CFCs could release chlorine in the stratosphere and destroy ozone.

State of the evidence

Documented

Midgley argued that TEL's danger was concentrated in manufacturing and handling the concentrated substance, claiming there was no evidence that exhaust gases at commercial concentrations were harmful. He also presented TEL as the essential available solution for engine efficiency, while public health experts urged greater caution.

State of the evidence

Documented

Attribution

Personally implicated

At Bayway's TEL production unit, several dozen workers suffered severe neurotoxic poisoning and five died. Together with deaths at other facilities, the incident triggered a national crisis, local bans and a temporary suspension of production.

At the height of the Bayway crisis, Midgley took part in a press conference, handling TEL with bare hands and inhaling its vapours to demonstrate that it could be handled without immediate harm. The demonstration became a symbol of industrial communications minimising risk.

State of the evidence

Well documented

Attribution

Directly implicated

Midgley identified tetraethyllead as an anti-knock additive and helped develop it at General Motors. Lead's hazards were already known and other approaches, including alcohol-based fuels, were being discussed; TEL nevertheless offered significant technical and commercial advantages.

State of the evidence

Well documented

Attribution

Directly implicated

Midgley himself suffered lead poisoning requiring convalescence. Meanwhile, serious cases and deaths occurred at pilot TEL production facilities; the industrial programme continued on the assumption that risks could be controlled through manufacturing procedures.

State of the evidence

Well documented

Attribution

Directly implicated