The present study was undertaken to investigate the pharmacokinetics o
f 1,8-cineol in human subjects during prolonged inhalation. The result
s showed that 1,8-cineol is well absorbed from breathing air, with a p
eak plasma concentration after similar to 18 min. The elimination of t
his fragrance compound from the blood is biphasic, with a mean distrib
ution half-life of 6.7 min and an elimination half-life of 104.6 min.