Informant38

Question

It is well known that when washing is hung out to dry in the open air the clothes develop a pleasant fresh smell. What is the reason for this and what chemicals are released?
E Ramon Moliner , Quebec

Answer
The agent responsible could be the Open Air Factor, a bacterial component of open air discovered by Harold Druett and Ken May at Porton Down in 1968.OAF is probably produced by the initial reaction between ozone and olefinic hydrocarbons from petrol or trees. It has the right properties to be attracted by damp washing, being highly condensable (zero vapour pressure) and having a high affinity for water.Considerable amounts could therefore concentrate in washing after only a few hours on the line. This is important when you are dealing with something like OAF which is in the parts-per-billion range in the air.OAF is unstable, and the fresh smell of washing is possibly caused by some volatile aldehydes being released when OAF splits, the remainder being an involatile polar peroxide.A systematic study identifying the aldehydes, leading perhaps to a PhD for someone, is clearly indicated here.
Tom Nash , Sherborne Dorset