Effectiveness of Disinfectants on Feathers

There are specialized machines designed to clean and sterilize feathers. Unfortunately these do not match the scale of small organizations and individuals. There is an abundance of information regarding different sterilization methods online. Since the September article on Feather Storage, we [the interns] ran two identical experiments testing the effectiveness of various disinfectants on feathers.  Although we were unable to determine which disinfectants were most effective, we did find that 70% isopropyl alcohol was the least damaging disinfectant.


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Twelve Blue and Gold macaw feathers were used. Two feathers were used as the control group. The rest of the feathers were put into separate treatment groups. To gauge effectiveness at freezing we placed two feathers in a plastic bag and kept in a freezer for 24 hours.  The remaining eight feathers were placed in groups of 2 and soaked in one of the following solutions: vinegar, Virkon, dish soap and water, or 70% isopropyl alcohol. The feathers were left in the different solutions for 10 minutes. One feather from each of the pairs was then rinsed with tap water.

After air-drying, the feathers were swabbed using sterile swabs. The Petri dishes containing the culture medium were then streaked using the swab. One week later the number of bacteria colonies in each Petri dish was counted. The feathers were visually examined to determine if the solutions damaged the feathers. Changes in color and structure were scrutinized by comparing feathers in treatment groups to the control feathers.


Both experiments are inconclusive for determining the strength of the disinfectants. In the first experiment nothing grew in the Petri dishes. In the second experiment mold grew in all the Petri dishes preventing an accurate count of bacteria colonies.


Treating the feather with isopropyl and freezing does the least damage while vinegar and Virkon do the most. None of the treatments affected the color of the feathers. Soap and water, Virkon, and vinegar caused the feathers to lose their shape.


The reason our two experiments did not come up with data is due to preparation. The error in our first experiment was overheating the culture medium. The culture medium we used, agar, needs to be turned into a liquid state from a gel state in order to pour it into the Petri dishes.  In the first experiment we used boiling water to heat the agar.  Unfortunately this denatured the agar, resulting in no available nutrients for bacteria to feed. Learning from this mistake, for our second experiment we melted the agar using a microwave. The second experiment failed due to lack of a sterile environment.  Even though we disinfected all our tools, containers and surfaces before experimentation, we did not work in a sterile environment. If we were to run this experiment again we would need to work in a laboratory setting. 

Although no correlation can be found between the amount of bacteria present and the treatment methods, disinfectant causes less damage to feathers than expected. Interestingly none of the disinfectants leached any of the color out of the feathers.  Rinsing feathers in either isopropyl or freezing them seems to do the least damage to them.


Blog by Ian Glascock