(1) In all actions involving fault of more than one entity, the trier of fact shall determine the percentage of the total fault which is attributable to every entity which caused the claimant's damages except entities immune from liability to the claimant under Title
51 RCW. The sum of the percentages of the total fault attributed to at-fault entities shall equal one hundred percent. The entities whose fault shall be determined include the claimant or person suffering personal injury or incurring property damage, defendants, third-party defendants, entities released by the claimant, entities with any other individual defense against the claimant, and entities immune from liability to the claimant, but shall not include those entities immune from liability to the claimant under Title
51 RCW. Judgment shall be entered against each defendant except those who have been released by the claimant or are immune from liability to the claimant or have prevailed on any other individual defense against the claimant in an amount which represents that party's proportionate share of the claimant's total damages. The liability of each defendant shall be several only and shall not be joint except:
(a) A party shall be responsible for the fault of another person or for payment of the proportionate share of another party where both were acting in concert or when a person was acting as an agent or servant of the party.
(b) If the trier of fact determines that the claimant or party suffering bodily injury or incurring property damages was not at fault, the defendants against whom judgment is entered shall be jointly and severally liable for the sum of their proportionate shares of the claimants [claimant's] total damages.
(2) If a defendant is jointly and severally liable under one of the exceptions listed in subsections (1)(a) or (1)(b) of this section, such defendant's rights to contribution against another jointly and severally liable defendant, and the effect of settlement by either such defendant, shall be determined under RCW
4.22.040,
4.22.050, and
4.22.060.
(3)(a) Nothing in this section affects any cause of action relating to hazardous wastes or substances or solid waste disposal sites.
(b) Nothing in this section shall affect a cause of action arising from the tortious interference with contracts or business relations.
(c) Nothing in this section shall affect any cause of action arising from the manufacture or marketing of a fungible product in a generic form which contains no clearly identifiable shape, color, or marking.