When you ask 'harmful' species, do you mean a microorganism? Or other harmful molecules/substances? This depends on how the cannabis flower had been grown and how the CBD had been extracted from the flower, ie. what solvent was used etc. As a tincture/oil is a concentration of product from the cannabis flower/plant (and this plant is a bioaccumulater) , it is quite possible that harmful molecules may be present and laboratory testing is of paramount importance to detect contamination, qualitative and quantitatively.

Thank you for the insight. I mean thermal degradants from the vaping process. They could come from oil or the cannabinoids, terpenes or other components. Just trying to see if any research has been done in this area.

Hi Ling! I don't know the answer for certain, but here is a reference that might be helpful:

https://www.nature.com/articles/s41598-021-88389-z

Michelle Peace at VCU has published a lot of research on e-cigarettes, vaping, and related matters. She would be a good person to ask the question.

Thank you, Chip!