The possible exposures to polychlorinated-biphenyls (1336363) (PCBs) from ballast burnout were discussed, based on surveys carried out in schools in Ohio, Washington, Virginia, Delaware, and Michigan. PCBs were contained in the smoke and leaking fluid from burned out fluorescent lamp ballasts manufactured prior to 1978. During a ballast burnout, the asphalt which surrounds the capacitor vaporizes, releasing an acrid smoke with an objectionable odor. Short term exposure did not appear to cause significant health risk. However, acute symptoms included headache, eye irritation, sore throat, nasal congestion and nausea. In one school, PCB air concentrations were as high as 4 micrograms per cubic meter (microg/m3) the week after ballast burnout, and dropped to 1microg/m3 after 5 weeks, which was still considerably higher than the background level of 0.33microg/m3. In a school with poor ventilation, PCB levels in air were 0.40 to 2.09microg/m3 1 month after ballast burnout; 2 months after improper cleanup, they remained at about the same level. Proper cleanup procedures reduced this to background levels. Background concentration on horizontal surfaces ranged from nondetected to 240microg/m3. Normal use of surfaces and daily cleaning probably reduced these levels. The authors conclude that because of the low acute toxicity, immediate effects are unlikely. Steps to be taken after a ballast fails were described. The authors recommend that old ballasts be replaced with PCB free ballasts manufactured after 1978.