Although talc has been used as a pleurodesis agent since 1935, a steri
lization protocol has not been established. We obtained USP asbestos-f
ree talc from six different suppliers and sterilized each using dry he
at, gamma irradiation, and ethylene oxide gas, Aerobic, anaerobic, and
fungal cultures were obtained prior to sterilization, and 1, 30, and
90 days after sterilization, Bacillus species were cultured from all s
ix unsterilized specimens and coagulase-negative Staphylococcus grew f
rom two unsterilized specimens, No growth of organisms was found follo
wing any method of sterilization. The cost of sterilization per 5-g pa
cket of talc was $4.74, $7.85, and $16.25 for heat, ethylene oxide, an
d gamma irradiation, respectively, In conclusion, untreated talc is no
t sterile, Sterilization by prolonged dry heat exposure, ethylene oxid
e gas, and gamma irradiation are all effective, with dry heat being th
e least expensive.