Can a party challenge the impartiality of an arbitrator at an arbitration?

Arbitrators must act impartially and their findings set aside where a party demonstrates they have not acted impartially. The party need to show only a reasonable apprehension of bias, not actual bias. In Szilard v. Szasz, 1954 CanLII 4 (SCC), [1955] S.C.R. 3 at 6-7, Rand J. held: These authorities illustrate the nature and degree of business and personal relationships which raise such a doubt of impartiality as enables a party to an arbitration to challenge the tribunal set up. It is a probability or the reasoned suspicion of biased appraisal and judgment, unintended though it may be, that defeats the adjudication at its threshold. Each party, acting reasonably, is entitled to a sustained confidence in the independence of mind of those who are to sit in judgment on him and his affairs... Nor is it that we must be able to infer that the arbitrator “would not act in an entirely impartial manner”; it is sufficient if there is the basis for a reasonable apprehension of so acting.