I looked at their site. It sounds like these are sawdust glued together with ... something. I tried to find an MSDS and it cannot be downloaded from their site. (Material Safety Data Sheet.) I didn;t think they could get away with that, but I suppose there is no requirement to make the MSDS available on the Internet.
Without knowing what is in the log there is no way I would use it for smoking. No way.
Looked again and found:
Is it okay to cook over the fire of a duraflame fire log?
No. Duraflame fire logs are not designed nor intended for use as a cooking fuel. Generally, the types of solid fuel used for cooking produce coals, which emanate heat over a period of time, and cooking is conducted by exposing the food directly to the heat generated by the coals. Our regular fire logs only burn with flames and do not generate adequate coals for cooking. For roasting food over a cozy fire, try duraflame Campfire Roasting Logs instead.
So if you saw Campfire Roasting Logs you can probably use those.