Letters: July 2024
Readers discuss DDT, reveal new information about Humphry Davy and ponder how to deal with errors
DDT history
The feature on DDT brought back memories. I have to hand a blurred photograph of myself at the laboratory bench, testing DDT.
I joined the Geigy Colour Company in Manchester in 1948 as a laboratory assistant. During the war, the resident Swiss MD was proud to receive a letter from Winston Churchill, praising the contribution of the factory to the war effort.
As Mike Sutton outlines, by 1950 it was necessary to cease DDT manufacture. We had to find an alternative use for the DDT production unit, equipment and employees. With the base chemical phenol already available on site, the choice fell to manufacture of N-acetyl-p-aminophenol, paracetamol. Considerable improvisation was necessary, and in the later stages of the first batch, debris from DDT wooden press plates was found floating in the paracetamol solution as it rested in a box filter.
The plant chemist went to nearby Woolworths and bought a pair of wellington boots and some children’s fishing nets. Donning the wellies, he spent the afternoon in the box filter and its contents, fishing out the floaters.
We joked that the first batch would not only cure your headache but get rid of anything that might be lurking in your hair.