California Code, Business and Professions Code - BPC § 17577.1

(a) “Contaminant” or “contamination” means any health-related physical, chemical, biological, or radiological substance or matter in water.

(b) “Water treatment device” means any product that (1) is designed to alter the chemical or physical properties or characteristics of water or plumbing or the seller, lessor, or renter claims can alter the chemical or physical properties or characteristics of water or plumbing and (2) is used or sold, leased, or rented for use on residential real property primarily for personal, family, or household purposes. “Water treatment device” does not include any device that is regulated pursuant to Chapter 7.5 (commencing with Section 4040) of Part 1 of Division 5 of the Health and Safety Code.

(c) “Person” means any individual, partnership, firm, corporation, or association, or any employee or agent thereof.