La. Code Civ. Proc. art. 591

A. One or more members of a class may sue or be sued as representative parties on behalf of all, only if:

(1) The class is so numerous that joinder of all members is impracticable.

(2) There are questions of law or fact common to the class.

(3) The claims or defenses of the representative parties are typical of the claims or defenses of the class.

(4) The representative parties will fairly and adequately protect the interests of the class.

(5) The class is or may be defined objectively in terms of ascertainable criteria, such that the court may determine the constituency of the class for purposes of the conclusiveness of any judgment that may be rendered in the case. This prerequisite shall not be satisfied if it is necessary for the court to inquire into the merits of each potential class member's cause of action to determine whether an individual falls within the defined class.

B. An action may be maintained as a class action only if all of the prerequisites of Paragraph A of this Article are satisfied, and in addition:

(1) The prosecution of separate actions by or against individual members of the class would create a risk of:

(a) Inconsistent or varying adjudications with respect to individual members of the class which would establish incompatible standards of conduct for the party opposing the class, or

(b) Adjudications with respect to individual members of the class which would as a practical matter be dispositive of the interests of the other members not parties to the adjudications or substantially impair or impede their ability to protect their interests; or

(2) The party opposing the class has acted or refused to act on grounds generally applicable to the class, thereby making appropriate final injunctive relief or corresponding declaratory relief with respect to the class as a whole; or

(3) The court finds that the questions of law or fact common to the members of the class predominate over any questions affecting only individual members, and that a class action is superior to other available methods for the fair and efficient adjudication of the controversy. The matters pertinent to these findings include:

(a) The interest of the members of the class in individually controlling the prosecution or defense of separate actions;

(b) The extent and nature of any litigation concerning the controversy already commenced by or against members of the class;

(c) The desirability or undesirability of concentrating the litigation in the particular forum;

(d) The difficulties likely to be encountered in the management of a class action;

(e) The practical ability of individual class members to pursue their claims without class certification;

(f) The extent to which the relief plausibly demanded on behalf of or against the class, including the vindication of such public policies or legal rights as may be implicated, justifies the costs and burdens of class litigation; or

(4) The parties to a settlement request certification under Subparagraph B(3) for purposes of settlement, even though the requirements of Subparagraph B(3) might not otherwise be met.

C. Certification shall not be for the purpose of adjudicating claims or defenses dependent for their resolution on proof individual to a member of the class. However, following certification, the court shall retain jurisdiction over claims or defenses dependent for their resolution on proof individual to a member of the class.