Facebook Twitter LinkedIn Pinterest 
Leslie Bretherick with his "Handbook" and computor
Leslie Bretherick CChem FRSC

In writing Bretherick’s Handbook of Reactive Chemical Hazards, Leslie Bretherick, has contributed to the safety of numerous chemists since 1975.

Leslie Bretherick suffered from poor sight, eventually becoming virtually blind. He also stammered and was an active member of the British Stammering Association. His masterwork, Bretherick’s Handbook of Reactive Chemical Hazards, or more often just “Bretherick’s” has potentially saved many lives since its first edition was published in 1975. It includes information on numerous hazards that one might expect (for example benzene and silicon compounds), and a few that one might not (bats, can of beans, sunspots and supervisors).


Leslie Bretherick at the Royal Society of Chemistry

Leslie worked in chemical research, and became a senior project leader at BP Research Centre, Sunbury. In his spare time at BP, he gathered information about dangerous chemical reactions and incidents. This was prompted by reading a copy of Chemistry and Industry, in which an explosion in a lab involving chromium trioxide and acetic anhydride was described. Bretherick’s previous knowledge told him that this was a hazard, but the realisation that this knowledge had dropped out of the general scientific community’s consciousness prompted him to compile his book.

About seven years after starting the compilation, and continuing in his spare time only, Bretherick realised it would never be finished at the rate of writing. He then gained support from his employers and the first edition of the handbook was published in 1975. 

The assistant editor of Bretherick’s Handbook of Reactive Chemical Hazards, Dr Martin Pitt, describes Bretherick’s main work:

“This was no mere collection but a highly organised and structured collection of information which has been invaluable to those contemplating new reactions or scaling up existing ones. Unlike other compilations of single chemicals, this showed how chemical combinations had been shown to be dangerous, both specific pairs and general information on groups and trends. It is the kind of book which might be expected to have come from a large team of researchers - it is even more impressive from a single worker.

Many lives and a great many injuries have probably been saved by this unique achievement (which continues after his death with further editions), which is an essential reference in many laboratories and industries around the world.

For his unique contribution to chemical safety, and as a person who succeeded despite handicaps, I would like to nominate Leslie Bretherick.”

Leslie Bretherick saw an unmet need which he was capable of resolving, and, despite the size of the project, persevered in meeting it for the sake of the safety of others. He is an example of sticking at a long-term task to improve the wellbeing of other people. Bretherick worked on later editions of his handbook until his sight condition led to his retirement. His work has been continued in further editions.

In part of the handbook, entries take the form of a title with numbers listing when incidents have been reported and the source, as well as a short description of the incident, for example:

Leslie Bretherick


1. Anon., Chemical Engineer, 1993, 546/7, 33
2. Various, Chem. Eng. News, 1993, 71(38), 64; 71(41), 60
An explosion demolishing an empty building was dubiously attributed to ignition of methane evolved from bat droppings [1]. There was much argument as to the probability of this [2], the eventual conclusion being that sewer gas from a septic tank was responsible.

1. Anon., Site Safe News, 1991, Summer, (HSE, Bootle, UK)
2. Allan, M., CHAS Notes, 1991, IX(5), 2
3. Sagan, C. et al., Nature, 1993, 365(6448), 720

A dangerous oxidant by virtue of its oxygen content, responsible for almost all fires, dust and vapour-cloud explosions, and for many other incidents. When heated to decomposition, air produces fumes of highly toxic nitrogen oxides. Air is frequently encountered compressed in combustible containers (tyres) which can explode with fatal results. Sometimes combustion seems to be the cause of the burst, this may be attributed to excessive heating and prior decomposition reactions generating a gaseous fuel [1]. Another fuel source causing a similar burst was an emergency inflator powered by liquid propane/butane [2].

The editor has been told that air can be explosive in its own right in a eucalyptus wood on a hot day, and, having smelt one, does not find this absolutely incredible. Explosive air is sometimes also found in caves and mines when decaying vegetable matter is present.

From a theoretical and thermodynamic standpoint, air should be considered a poison to carbon-based life [3]. Handle with due caution.

Superiors/Supervisors: Can be a source of hazard. Some may react violently to suggestions that they are not omniscient. Suggested reactions should never be undertaken without investigating safety factors, not even if the editor is the superior in question.

Workers at the next bench: Are almost as dangerous as are you, dear reader. Make sure you know what he is doing and expect him to return the compliment.

Words by Jenifer Mizen
Images courtesy of Margaret Bretherick
Published January 2014

More faces...