Heritage · Legacy
Trevor Kletz Legacy
British chemical engineer (1922–2013) who pioneered process safety, originated inherently safer design, and championed HAZOP across the chemical industry.Written to last — not to trend.
By Confinity Heritage Editorial · Updated 2026-07-31 · 6-minute readQuiet tools, not a toolbar.
Trevor Kletz (1922–2013) was a British chemical engineer who did more than almost anyone to turn industrial safety from a matter of rules and guards into a question of design. Over 38 years at Imperial Chemical Industries (ICI) and a long second career as an author and lecturer, he argued that the safest plant is one that removes hazards rather than adding barriers around them. His principle of inherently safer design, and his tireless promotion of Hazard and Operability Studies (HAZOP), reshaped how the chemical industry thinks about risk.
Kletz was born on 23 October 1922 in Darlington, England, to Jewish parents of Russian descent (Wikipedia). He was educated at The King's School, Chester, then read chemistry at the University of Liverpool, graduating in 1944. That same year he joined ICI as a research chemist at its Billingham laboratories, the start of a career with the company that lasted 38 years (The Chemical Engineer). He spent roughly 16 years as a plant manager, running units that made iso-octane, acetone and tar acids, work that gave him a close feel for the hazards of chemical manufacturing. From 1955 he also served as a part-time safety officer at one of the company's works, an early sign of where his interests lay, before his career turned decisively toward safety.
In 1968 ICI appointed Kletz one of the process industry's first technical safety advisers, a role he held for 14 years (The Chemical Engineer). The 1974 Flixborough disaster, a vapour-cloud explosion that killed 28 people, sharpened his thinking about why plants failed so catastrophically. In a 1978 article titled "What You Don't Have, Can't Leak," he set out the idea that would define his career: if a plant holds only a small quantity of a hazardous material, or none at all, the consequences of a leak shrink with it.
From that starting point he developed the principles of inherently safer design: intensification, reducing the amount of hazardous material held; substitution, replacing dangerous substances with safer ones; attenuation, using hazardous materials under less dangerous conditions; and limitation of effects, designing so that failures do less harm (The Chemical Engineer). Rather than pile protective layers onto a risky design, he argued, engineers should design the danger out from the start.
Kletz is also closely tied to HAZOP, the structured technique for examining process designs for hazards and operability problems. He did not invent the method, which is generally credited to colleagues at ICI, but he did more than anyone to explain it, refine it and spread it, and through his advocacy it became standard practice across the industry.
Kletz retired from ICI in 1982 and began a second career as an author and lecturer that ran for three decades. He became a visiting professor at Loughborough University and later an adjunct professor in the chemical engineering department at Texas A&M University. He wrote more than a dozen books and over a hundred technical papers; What Went Wrong?, Learning from Accidents and Cheaper, Safer Plants remain standard reading in the field.
His influence went beyond any single technique, and colleagues came to call him the father of inherently safer design. He insisted that accidents be investigated as failures of systems and design rather than blamed on individual "human error," a shift that changed how companies and regulators learn from incidents (U.S. Chemical Safety Board). His honours reflected that reach: he was elected a Fellow of IChemE in 1978 and of the Royal Academy of Engineering in 1984, appointed OBE for services to industrial safety in 1997, and awarded the Society of Chemical Industry's Mond Award in 2009 (Wikipedia). He died on 31 October 2013, eight days after his 91st birthday. Asked late in life what he had done, he said, "I've saved a lot of people's lives. That's something I can be proud of."
Trevor Kletz's work is the kind that saves lives quietly, in decisions made years before anything could go wrong, and his name is far less known than the disasters his thinking helped prevent. Confinity keeps his record because a life spent making dangerous work safer deserves to be remembered as clearly as the accidents it averted, and because his central lesson, that safety belongs inside the design rather than bolted around it, outlives him.
Early life
Inherently safer design
Legacy
Why Confinity keeps Trevor
References
Timeline
- 1922Born in Darlington, England, to Jewish parents of Russian descent
- 1944Graduates in chemistry from the University of Liverpool and joins ICI
- 1968Appointed one of ICI's first technical safety advisers
- 1978Publishes 'What You Don't Have, Can't Leak', setting out inherently safer design
- 1982Retires from ICI and begins a second career writing and lecturing
- 1997Appointed OBE for services to industrial safety
- 2013Dies aged 91