Simulation or the Real Thing? Comparing Industrial Hygiene Tests Used for S2 Evaluations
(Omnia Safety, Union City CA)
SEMI S2 equipment evaluations require industrial hygiene testing to meet emissions limits during normal operations, maintenance tasks, and single point failures. SEMI F15 tracer gas simulation has been widely used to characterize semiconductor equipment exhaust. This method was developed for toxic gas release modeling. Many times equipment is characterized based on a standard 28 lpm leak rate: this simplification may provide results that have little correlation to an actual liquid leak. However, accurate results can require complicated evaporative modeling for accurate results using tracer gas methodology for liquid leak scenarios. On the other hand, proposing to spill concentrated liquid hazardous materials into equipment to test failures has its own drawbacks. A case study of semiconductor equipment evaluated with several methodologies will be presented. This case study compares the exhaust requirements resulting from different approaches using SEMI F15, NIOSH, and OSHA Test Methods. Key aspects of testing that significantly affect outcome will be considered. Comparing results of SEMI F15 tracer gas applications with traditional industrial hygiene sampling methodology, this presentation explores the outcomes of various test methods when applied to equipment handling liquid hazardous materials.