INTRODUCTION : In the first unit of this block you read about hazards due to electricity and gases in the science laboratories. 'The second unit deals with yet another type of common hazard which is because of fire. The consequences of fire are well known; still many do not take enough precautions and preventive measures. According to National Crime Record Bureau, the number of deaths in our country due to fire accede its during 1994 and 1995 are 23050 and 21226, respectively. The person-in-charge of any laboratory should have a knowledge to handle a fire hazard. In case the fire spreads beyond control, the laboratory staff should know how to call the fire brigade, raise the alarm and ask for other help. In this unit, you will learn about the major causes of fire, its classification, precautions and prevention. You will also learn about the fire extinguishers. The next unit deals with hazards in handling chemical and radioactive materials.