Six students and two staff members at the University of California, Davis, became sick this morning shortly after working with a chemical during an experiment in a nutrition research laboratory. The students appeared to have inhaled fumes while handling the chemical phenylmethylsulfonyl flouride -- an enzyme inhibitor that can have neurotoxicological effects. They experienced shortness of breath, vomiting and diarrhea. They were treated on site and seven were forwarded to Sutter Davis Hospital. One student was admitted and the others were released. Some have returned to campus. The campus emergency operations team responded to a call at 10:22 a.m. to attend to the students and investigate the situation. The incident appears to have been caused by a laboratory protocol problem. No existing fumes remain or escaped elsewhere. Part of the Meyer Hall building was temporarily evacuated.