Science Buddies: "Ask an Expert"

Is it a good thing if triclosan degrades?

Also, does anyone have any catchy title ideas for this project? (dealing with photolytic degradation of triclosan)

Thanks!!

Hi,

Here are some papers on the photolysis of triclosan (found by a Google search for “photolysis of triclosan”):

http://www.beyondpesticides.org/antibac ... 0water.pdf

http://www.ncbi.nlm.nih.gov/pubmed/17305142

http://www.envirofacs.org/Pre-prints/Vo ... 01/p38.pdf

http://www.sciencedirect.com/science?_o ... archtype=a

http://www.sciencedirect.com/science?_o ... archtype=a

http://onlinelibrary.wiley.com/doi/10.1 ... 1/abstract

http://www.springerlink.com/content/e34605354l0t9562/

http://www.beyondpesticides.org/antibac ... 0water.pdf

As to what the importance of photolysis is if it occurs, here is a study by the EPA on the subject:

http://oehha.ca.gov/prop65/public_meeti ... ciba10.pdf

Generally the answer depends on the toxicity to the environment of triclosan and its photolysis products. Ideally one would like to see triclosan degrade rapidly into very nontoxic compounds which have no impact on the environment. There is a real problem if triclosan or any degradation product accumulates in any organism to the point of beung toxic to that organism or any organism that eats it.

This sounds like a very interesting project. Have fun with it!

Best regards,

Barrett L Tomlinson

Thank you very much!!That really helps!

From my research, triclosan is known to degrade into dioxins and other harmful substances. So, it isn't very good for the environment if it degrades. But, if I am only testing if photolysis occurs, and not what the photolysis products are, would if be okay to say that degradation is still bad to the environment??

Hi,

I am glad to see you have done your own research on the photolysis products. Yes, I do think it is OK to talk about the problem caused by the degradation of triclosan. You can reference your sources to support your statement. You may want to research the specific dioxin isomer(s) produced by photo degradation, as they vary quite widely in their toxicity, ranging from extremely toxic to almost nontoxic. Here is a resource on the relative toxicity of the many isomers:

http://www.dtsc.ca.gov/AssessingRisk/upload/chap9.pdf

You sound like you are on your way to a very successful project!

Good luck and have fun!

Best regards,

Barrett L Tomlinson

Thank you very much!! I have one more question..

Does the solubility of a chemical affect the degradation rate? For example, if triclosan is more soluble in a higher pH, does that mean that the chemical will degrade faster in a higher pH buffer solution? If that is true, why is that?