On 16th August 2016 at 10.00 pm. Ms.Supapron Ermsa-ard (LAB Operator) she is working product test at Lab room and press stop the Oven mc. Because the Coulometer mc. not print report by period set 600 seconds. After Oven mc. Stop working. Chemicals (~5 cc.) reverse flow from the Stirrer mc. into the tubes test Moisture inside the Oven mc. And, while it also has a heat cause chemical reaction with the heat inside the tubes test Moisture have a burning odor occurs in the LAB room immediately. Employee inform supervisors immediately at 22.15 p.m. and inform Safety officer at 22.30 p.m.