I would like to plant a non-toxic hedge about 2 mètres high max, 1metre wide, screening, some sun but mostly shaded area, good drainage soil.
What do you suggest?
We assume you are referring to toxicity towards humans and household pets. You should avoid evergreens such as yews, all parts of which are toxic, and junipers, whose berries are poisonous.
Some hedging plants to consider would be the Eastern White Cedar, with a preference for Thuja occidentalis “DeGroot’s Spire” over Thuja occidentalis “Smaragd” or Emerald Cedar as the former is more reliable in Ontario.
If you are thinking in terms of a deciduous hedge, either Beech or Hornbeam would be good choices (although beech nuts are toxic to horses). Here is a link to a previous Toronto Master Gardeners question which compares the qualities of these two hedging materials.
Any of these hedges would require some pruning to keep them shapely.