In some circumstances, materials that are being heated in the lab could catch fire. If a flammable substance in a beaker should catch fire while you are working but the flames are relatively contained, which method must never be used for extinguishing the flame?

Select one:

a. Turn off the heat source immediately, and use a watch glass to cover the beaker and minimize the oxygen around the flame.

b. Use water from the sink nearest the bench to douse the flames.

c. Use the chemical fire extinguisher located in the lab. Pull the pin, aim the nozzle into the beaker, and pull the lever.