A sample of the subject material, CIS 2,3-epoxy butane, was submitted to the Biochemical Research Laboratory for toxicological investigation and definition of industrial handling hazards. The material is an experimental chemical. The subject material possesses a low acute oral toxicity and should pose no problem from ingestion incidental to industrial handling. The undiluted material is slightly to moderately irritating to the eye. Direct eye contact would likely result in some conjunctival redness and swelling accompanied by slight transient corneal injury all of which would be expected to subside within a few days. Permanent effects would not be anticipated. Safety glasses are recommended for industrial handling whenever the likelihood of eye contact exists. The undiluted subject material is only slightly irritating to the skin from a primary irritation viewpoint.