A Bunsen burner is common laboratory equipment that produces an open gas flame for various scientific applications. Its primary purpose involves heating substances, sterilizing equipment, and facilitating combustion in controlled environments. This guide covers how to safely light, manage, and extinguish a Bunsen burner.
Safety First
Before operating a Bunsen burner, ensure a safe environment. Wear safety goggles to protect your eyes. Clear the work area of all flammable materials, such as papers and chemicals, and position the burner at least 12 inches from overhead shelving.
Inspect the gas hose connecting the Bunsen burner to the gas jet for any signs of cracks, holes, or damage, replacing it if defects are found. Confirm the hose fits securely onto both the gas valve at the bench and the burner’s gas intake. Know the location of the main gas shut-off valve for the laboratory and ensure proper ventilation is established before proceeding.
Step-by-Step Lighting
Lighting a Bunsen burner requires a precise sequence for safety and efficiency. Securely attach the rubber tubing from the gas inlet on the burner’s base to the gas jet on the laboratory bench. Before turning on the gas, ensure that the air hole (controlled by the collar) at the base of the burner is closed or mostly closed, as this creates a more visible, safer flame for lighting. Confirm that the gas control valve on the burner itself is fully closed.
Once these preliminary steps are complete, turn on the main gas supply valve at the bench, typically by aligning its handle parallel with the gas line. Have a striker or igniter ready; if using a striker, check that it produces sparks reliably. Slowly open the gas control valve on the Bunsen burner while bringing the lit igniter just above the barrel. The gas should ignite with a soft pop, producing a yellow, luminous flame. If the burner does not light immediately, turn off the gas at the main supply, recheck connections, and repeat the procedure, ensuring the gas control valve is opened gradually.
Managing and Extinguishing the Flame
Once lit, adjust the flame to suit your experimental needs. The air hole collar at the base of the barrel regulates the amount of air mixing with the gas. Rotating the collar to allow more air transforms the initial luminous yellow flame into a non-luminous blue flame, which is hotter and preferred for most heating due to its efficiency and lack of soot production. The hottest part of this blue flame is just above the inner blue cone.
Conversely, closing the air hole collar will return the flame to a cooler, more visible yellow flame, often referred to as a safety flame. This luminous flame is useful for observing status but not for strong heating. The height and intensity of the flame can also be adjusted by turning the gas control valve at the burner’s base; opening it further increases gas flow and flame size, while closing it reduces both. When finished using the Bunsen burner, first close the gas control valve on the burner, then turn off the main gas supply valve at the bench by rotating its handle perpendicular to the gas line. Allow the burner to cool completely before handling or storing it, as it remains hot after use.