Parties subject to an arbitration agreement may challenge whether a particular arbitrator may hear a matter.  If the contract does not specify particular arbitral rules (AAA or JAMs, for instance), then the parties must rely on the laws of the place of the arbitration to determine the circumstances under which an arbitrator may challenged.

Under the Rules of the American Arbitration Association, and arbitrator may only be challenged for: 1) partiality or lack of independence; 2) inability or refusal to carry out his duties diligently and in good faith; or 3) any ground for disqualification specified by the applicable law.  Rule 18, American Arbitration Association Rules.

Under the Rules of JAMS, the parties must object to the service of an arbitrator within ten days of his or her appointment based on the disclosure of any circumstance likely to give rise to justifiable doubt about the arbitrator’s impartiality or independence. JAMS Rule 15(h).  Any party may challenge the continued service of the arbitrator at any time if  the party discovers information that was not available to the parties at the time the arbitrator was selected.  JAMS Rule 15(i).  JAMS arbitrators have an immediate and continuing obligation to disclose known or apparent conflicts of interest.  JAMS Arbitrators Ethics Guidelines,