Recent Brazilian Guidelines on Arbitrators' Duties of Disclosure

14 August 2025

The Brazilian Arbitration Committee has issued Guidelines on Arbitrators' Duty of Disclosure that will assist parties to arbitrations seated in Brazil or governed by the rules of Brazilian arbitral institutions. The Guidelines have the potential to help prevent disruptive tactics and to increase the efficiency of proceedings.

In 2024, the Brazilian Arbitration Committee (Comitê Brasileiro de Arbitragem, "CBAr") released its Guidelines on the Arbitrator's Duty of Disclosure (the "CBAr Guidelines"). This document was developed as an institutional response to a perceived need for tools promoting the efficiency of arbitral proceedings, in the context of a booming Brazilian arbitration landscape, in which some parties tend to raise their concerns regarding an arbitrator's potential conflict of interest as a strategy to disrupt or slow down the proceedings.

The CBAr Guidelines include 11 guidelines. They draw their inspiration from the seven General Standards of the International Bar Association's Guidelines on Conflicts of Interest (the "IBA Guidelines"), the leading instrument relating to arbitrators' duty of disclosure and the assessment of potential conflicts of interest. The CBAr Guidelines provide useful guidance to assess the facts an arbitrator should disclose, the timing of the disclosure, and the standard applicable to a potential conflict of interest, largely reflecting international practice.

A flexible non-binding instrument

The CBAr Guidelines are a non-binding instrument that parties may agree to adopt in proceedings through the first procedural order or the terms of reference. According to Guideline 1, the CBAr Guidelines aim to provide flexibility to the parties and are not intended to be read as a strict instrument. Guideline 10 allows the parties to modify the guidelines upon mutual agreement, adjusting to the specificities of each arbitration, and to those of arbitration in Brazil.

The arbitrator's duty of disclosure

The CBAr Guidelines largely reflect best practice in arbitration, in Brazil and internationally. The CBAr Guidelines maintain the Brazilian law standard for the arbitrator's duty to disclose. Guideline 2 expressly refers to Article 14, paragraph 1 of the Brazilian Arbitration Act, which requires an arbitrator to disclose "any circumstance likely to give rise to justifiable doubts as to his impartiality". This subjective standard is also aligned with IBA General Standard 3, providing for the arbitrator's duty to disclose any facts or circumstances that "may, in the eyes of the parties, give rise to doubts as to the arbitrator's impartiality or independence".

Timing of the duty of disclosure

Pursuant to Article 14 paragraph 1 of the Brazilian Arbitration Act, the duty of disclosure arises at the stage prior to the arbitrator's acceptance of their appointment. CBAr Guideline 2 extends the duty of disclosure throughout the proceedings and until the end of the arbitrator's mandate. This aligns with the widely accepted ongoing duty of disclosure set forth in IBA General Standard 3(a).

The failure to disclose and the assessment of conflicts of interest

Like the IBA Guidelines, the CBAr Guidelines' standard for the assessment of conflicts of interest is an objective one, from the perspective of a "reasonable third-party". Pursuant to Guideline 3, the arbitrator's failure to disclose does not necessarily imply a lack of independence or impartiality. This presumption in favour of the arbitrator's independence and impartiality can also be found in IBA General Standard 3(g).

Guideline 3 provides for an in concreto assessment of the alleged conflict of interest, considering the nature and relevance of the undisclosed fact, from the perspective of a reasonable third-party. IBA General Standard 2(b) provides a similar objective test to assess the potential conflict of interest resulting from undisclosed facts or circumstances, also from the perspective of a "reasonable third person".

The adoption of this dichotomy between a subjective standard of disclosure and an objective standard for the assessment of conflicts of interest is a welcome endorsement of the concepts developed by international arbitration practice over several years, as reflected in the IBA Guidelines. It contributes to a wider acceptance of these principles and strengthens legal certainty. The CBAr Guidelines thereby have the potential to prevent potential dilatory tactics based on unmeritorious challenges concerning alleged conflicts of interest.

The parties' duties

The CBAr Guidelines impose two duties on the parties, that are the corollary of the arbitrator's own duties of disclosure, independence and impartiality.

Guideline 5 provides for a duty of collaboration requiring the parties to provide the arbitrator with all relevant information that may be necessary to conduct conflict of interest verifications and to make any necessary disclosures.

Guideline 6 provides for a duty of due diligence, requiring the parties to look for publicly available information that may have an impact on the arbitrator's independence and impartiality prior to the acceptance or confirmation of the arbitrator. Guideline 6 further establishes a burden on the parties of "informing themselves about public and easily accessible facts" allowing them to "conduct their own research to ensure the proper exercise of the arbitrator's duty of disclosure", provided they use lawful means. CBAr Guideline 6.1 thus excludes "requiring specific disclosure by the arbitrator" of publicly available information, accessible to the parties. The parties are further required to raise any objections to the arbitrator's independence or impartiality at the first opportunity.

Similarly, IBA General Standard 7 sets out a series of duties of the parties with respect to arbitrators' duty of disclosure. Pursuant to IBA General Standard 7(b), the parties must conduct the necessary inquiries and provide the relevant information for the arbitrator to determine whether disclosures are necessary.

CBAr Guideline 6.2 further grants the parties the opportunity to inquire directly with the arbitrator about specific circumstances, as well as their law firm. Guideline 6.2 allows the parties to formulate different rounds of questions to the arbitrator. After the first round of questions, the subsequent rounds are limited to referencing the answers to previous questions. The CBAr Guidelines thereby seek to limit the scope of the questions that may be asked, to counter a common practice in Brazil of formulating successive lists of questions to the arbitrator as a strategy to disrupt the proceedings.

The waiver of challenges concerning the arbitrator's independence and impartiality

Guideline 7 provides guidance as to the appropriate timing for raising concerns regarding the arbitrator's independence or impartiality. The parties must raise any potential challenge to the arbitrator's independence or impartiality at the first opportunity after the relevant information is disclosed or comes to their attention. Failure to do so precludes the party from relying on such information at a later stage, particularly in the context of annulment proceedings. This aims at preventing a party from strategically withholding information that may give rise to doubts as to the arbitrator's independence only to later use that information to jeopardize the arbitration.

In this regard, the CBAr Guidelines maintain a closer connection to the Brazilian Arbitration Act than to the IBA Guidelines, by incorporating a reference to Article 20 of the Brazilian Arbitration Act, which expressly provides for the same timing limitations to challenges on the grounds of conflicts of interest. Guideline 8 provides that a party who presents facts that may give rise to doubts as to the arbitrator's independence or impartiality only after the end of the arbitrator's mandate, must justify the reasons for why the information was not obtained earlier.

The IBA Guidelines adopt a different approach to the timing for challenging an arbitrator based on conflicts of interest. IBA General Standard 4 operates as a waiver of potential conflicts of interest. It grants a 30-day time limit for the parties to raise objections to the relevant arbitrator's appointment from the date of receipt of the arbitrator's disclosure, or from the date when the interested party learned of the facts or circumstances that would allegedly constitute a conflict of interest.

Comment

By adapting international arbitration best practice to the reality of arbitration in Brazil, the CBAr Guidelines have the potential to be a reliable instrument for parties to Brazil-related arbitrations. While their relevance and use is yet to be tested, they will no doubt contribute to spreading and strengthening best practice in one of the most prominent arbitration markets.