Canadian Nutrient File. Does ESHA software include the Canadian Nutrient File?

Yes.

In some cases the Canadian Nutrient File is hidden from searching. To check this (and enable it in searches)

1. Click View / Preferences.
2. On the left, click the Groups to Exclude page (or, possibly Search page in older versions).
3. On the right, expand Databases (click the +)
4. Any Group selected here is excluded from searches.  Uncheck any Group you wish to include when searching.
5. Click OK.