Acetic acid
From Tardis Wiki, the free Doctor Who reference
Acetic acid was the main component of vinegar. As an acid, it had a sour taste and smell. It was lethal to the calcium-based Raxacoricofallapatorians, (TV: World War Three [+]Loading...["World War Three (TV story)"]) and according to the Thirteenth Doctor its scent could be used to repel spiders. (TV: Arachnids in the UK [+]Loading...["Arachnids in the UK (TV story)"])
