This investigation of formaldehyde exposure in school laboratories, where its principal source is from preserved biological specimens, was undertaken because of concern over exposure levels reported in the literature. Information was obtained in two ways. A limited survey of schools was conducted to determine extent of students' use of preserved specimens. Various producers of preserved specimens were also surveyed to obtain information on sales, general industry practices, and availability of substitutes. Air measurements in classrooms where dissection was underway and specific information on specimens used, class size, and general ventilation in school laboratories/classrooms were obtained in another study. Among the results reported are findings that use of formaldehyde-preserved specimens exposes students/teachers to formaldehyde levels in excess of background exposure and that industry, aware of the toxicity problem, has developed new-technology packing media which significantly reduces such emissions. (JN)