Generally, it would be highly unusual to challenge the arbitrator you selected, but it can happen if circumstances arise under which it would be appropriate to challenge the independence, impartiality or fulfilment of obligations of the arbitrator.
More common are challenges of arbitrators appointed by the other party(res) to an arbitration. Unfortunately, many challenges are strategic and spurious, and such challenges can give rise to delays in the appointment process.
The normal grounds for challenging an arbitrator are lack of independence and impartiality. Parties often research the background of an arbitrator they wish to challenge to see if they can find any links between the arbitrator and the parties involved or even if an arbitrator has published articles on the topic in dispute.
Arbitrators are subject to disclosure requirements and duties to analyse their own independence. They also must preserve their reputation in order to potentially be appointed for future arbitrations.
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