"For centuries, humans have been perplexed by the musty metallic odor associated with the handling of iron objects or rubbing away a drop of blood from a cut. Also perplexing is the garlicky odor noticed by metallurgists when cast iron rich in carbon and phosphorus is treated with an acid."*
The answer to these perplexing questions has been found, and the work was published in the Angew. Chem. Int. Ed. 2006, 45, 7006.
The musty odor is due to the formation of 1-octen-3-one, and the garlicky odor is due to substituted phosphines such as methyl or ethyl phosphine. The musty odor arises from contact of human perspiration with iron, and the substituted phosphines arise from reaction of the acids with phosphorus in the cast iron.
*Taken from C and E News October 30, 2006
Posted by E. A. Ford/MTI