Biomaterial Database

Effects of temperature and relative humidity on biological indicators used for ethylene oxide sterilization. 1983

G S Oxborrow, and A M Placencia, and J W Danielson

A study was made to determine the effects of temperature and moisture on the D-value of a common biological indicator. Relative humidity (RH) was varied between 10 and 70% in increments of 10%, and temperature was varied between 30 and 70 degrees C in increments of 10 degrees C. Temperature was found to have a pronounced effect on the D-value. At 60% RH, the D-value varied from 15.0 min at 30 degrees C to 1.1 min at 70 degrees C. When RH was plotted against the average D-value at the various temperatures, the temperature curves at or above 50 degrees C were more erratic and the RH had a significant effect. The study showed that temperature and RH must be controlled if biological indicators are to be properly calibrated for use in ethylene oxide sterilization.

UI	MeSH Term	Description	Entries
D005027	Ethylene Oxide	A colorless and flammable gas at room temperature and pressure. Ethylene oxide is a bactericidal, fungicidal, and sporicidal disinfectant. It is effective against most micro-organisms, including viruses. It is used as a fumigant for foodstuffs and textiles and as an agent for the gaseous sterilization of heat-labile pharmaceutical and surgical materials. (From Reynolds, Martindale The Extra Pharmacopoeia, 30th ed, p794)	Oxirane,Oxide, Ethylene
D006813	Humidity	A measure of the amount of WATER VAPOR in the air.	Humidities
D001412	Bacillus subtilis	A species of gram-positive bacteria that is a common soil and water saprophyte.	Natto Bacteria,Bacillus subtilis (natto),Bacillus subtilis subsp. natto,Bacillus subtilis var. natto
D013171	Spores, Bacterial	Heat and stain resistant, metabolically inactive bodies formed within the vegetative cells of bacteria of the genera Bacillus and Clostridium.	Bacterial Spores,Bacterial Spore,Spore, Bacterial
D013242	Sterilization	The destroying of all forms of life, especially microorganisms, by heat, chemical, or other means.
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures