The Bunsen burner, a workhorse of biology and chemistry labs around the world for decades, might have been getting more credit than it deserves.
Many scientists have long relied on Bunsen burners to decontaminate airspace and surfaces in labs. The burners’ flames were thought to create convection currents that carry microbe-containing particles away from the lab bench. Now, a study has found not only that the devices are ineffective at cleansing workspaces of bacteria-laden particles, but that they can even make contamination worse.
The work was published in August in Microbiology Spectrum1.
Even before the study came out, biologists had divided opinions about Bunsen burners, says Hannah Gavin, a microbiologist at Providence College in Rhode Island and a co-author of the paper. Some researchers swore by the burners’ ability to sterilize research spaces, but others had doubts. The study could fuel debate about whether this low-tech device still has a place in the modern laboratory. It could even be the “nail in the coffin” for the burners’ use in biology labs, says Amir Mitchell, a systems biologist at the University of Massachusetts Chan Medical School in Worcester.
That’s the first I’ve ever heard of that and I find it odd they’d ever think it, being scientists, you know. I mean, what do we have here, an open gas flame? When did anyone ever think an open gas flame was purifying and antiseptic?
Bizarre. I never heard of such a thing. Anybody with a lick of sense knows that gas flames pollute, incomplete combustion is one of the biggest problems, and even the most efficient aren’t 100%.
One of the biggest jobs of the lamplighters of an earlier era wasn’t just lighting the gas lamps, it was cleaning the globes which the incomplete combustion and carbonization turned filthy, diminishing the lighting they worked so hard to get in the first place.
I had a double major in Chemistry and Biology in college and took many lab courses. I never, ever heard of the absurd claim that a bunsen burner flame would sterilize lab air.
Someone needed to order a pizza and thought they would make some money by publishing an article. Garbage.
Wendy
A properly adjusted Bunsen burner burns with a blue flame. It is not a lamp. Gas lights did not burn natural gas. Manufactured gas required special treatment to give yellow flame. Gas was produced heating coal red hot and blowing steam through it resulting in mix of hydrogen and carbon monoxide. Gas was bubbled through “coal oil” to give yellow flame.
Heat from a Bunsen burner flame is the sterilizing mechanism. Heating wire red hot in burner flame has long been used to sterilize when inoculating media in a Petrie dish.
Coleman camping lamps create light by heating a ceramic mantle white hot.
Spaces, not items. I get that you burn something long enough nothing can live on it. But “spaces” is another thing. How does a bunsen burner cleanse the space? It doesn’t. Ridiculous. And I can’t believe scientists thought so. Ridiculous article, probably written by someone who didnt do so well in Chem lab.
Wiping down a lab bench w bleach is probably routine practice in labs that handle biological materials. Some probably object to the odor and exposure to “chemicals.” You can understand “flaming” the area as a “clean” alternative. But apparently not as effective as thought. But maybe methodology needs to be improved.
How? Because surfaces and surrounding air are not going to be affected unless these whacky scientists “flame” with something a little larger than Mr. Bunsen.
I don’t think surrounding air is the concern. If working with materials that contaminate air, fume hoods are usually used.
Spilled materials can contaminate surfaces. Wiping down surfaces is standard practice.
When you work in a hospital laboratory you know the samples you test are from sick patients. Hepatitis, aids, pneumonia, syphilis, and many more cross your bench every day. Then you realize the need to be careful. Sterilizing surfaces can be good practice.
Microbiologists often use Bunsen burners to reduce airborne microbial contamination in their workspace. In theory, the burner’s flame pushes air—and the microbe-containing particles therein—up and away from research materials. This is purported to create a disinfected zone that improves asepsis. While such use of a Bunsen burner is promoted in numerous textbooks, peer-reviewed publications, and university-affiliated websites, our search for data on Bunsen burner efficacy revealed a dearth of experimental evidence in scientific literature. Therefore, we designed and conducted a series of laboratory experiments to test the utility of this method, hypothesizing that the flame would reduce airborne contamination. We intentionally inoculated the air in a laboratory space with bacteria, then collected data on the deposition of airborne contaminants using a paired settle plate method. On average, plates adjacent to an active Bunsen burner do not experience a reduction in colony-forming units (CFU) settling. Linear regression indicates that results are environmentally context dependent: plates adjacent to Bunsen burners with 18 mm flame diameter exhibit mildly decreased deposition of dry particles when control contamination rates exceed 83 CFU/min, but increased dry particle deposition at contamination rates below that cutoff. Duration of flame activity is not associated with improved aseptic outcomes, regardless of flame size or particle moisture. Taken together, these data suggest that 18 mm Bunsen burners should be selectively implemented only in situations of “high and dry” airborne contamination. Outside this specific context, their activity is either neutral or detrimental to laboratory asepsis.
