Laboratory and field validation of a JXC charcoal sampling and analytical method for monitoring short-term exposures...

A sampling and analytical method for the measurement of ethylene oxide (EtO) short-term exposure limits (STEL) was validated under both laboratory and field conditions. These studies were designed to examine the method against both the Occupational Safety and Health Administration (OSHA) EtO permissible exposure limit (PEL) method requirements and the National Institute for Occupational Safety and Health (NIOSH) industrial hygiene method validation criteria. The method's pooled accuracy was shown to be within both OSHA requirements and NIOSH guidelines. The EtO was collected on a JXC charcoal tube at a sample flow rate of 100 mL/min for 15 min. The samples were shipped on dry ice and were stored in a freezer until analyzed. The EtO was desorbed by carbon disulfide and the eluent was analyzed by gas chromatography with flame ionization detection (GC-FID). The desorption efficiency of EtO from JXC charcoal tubes was determined to be 84% over the 15-min time-weighted average concentrations: 2.5, 5.0 and 10 ppm EtO. The method limit of detection was determined to be 1.0 ppm. The coefficient of variation of the combined sampling and analytical method was 5.7%. A -7% method bias was calculated. Field validation of the method included data from a portable GC-FID for the determination of method bias. Results of the field validation study over the concentration range of 2.4 ppm to 19.9 ppm generated a field precision of 8.1% with an absolute bias of 3.9%. The method accuracy was determined to be +/- 20%.(ABSTRACT TRUNCATED AT 250 WORDS)