# 790.3 Definitions.
Terms defined in the Act and not explicitly defined herein are used with the meaning given in the Act. For the purpose of this part:
*Act* means the Toxic Substances Control Act, 15 U.S.C. 2601 *et seq.*
*Additive* means a chemical substance that is intentionally added to another chemical substance to improve its stability or impart some other desirable quality.
*Central Data Exchange* or *CDX* means EPA's centralized electronic submission receiving system.
*Chemical* means a chemical substance or mixture.
*Chemical Information Submission System* or *CISS* means EPA's electronic, web-based tool for the completion and submission of data, reports, and other information, or its successors.
*Consortium* means an association of manufacturers and/or processors who have made an agreement to jointly sponsor testing.
*EPA* means the U.S. Environmental Protection Agency.
*Equivalence data* means chemical data or biological test data intended to show that two substances or mixtures are equivalent.
*Equivalent* means that a chemical substance or mixture is able to represent or substitute for another in a test or series of tests, and that the data from one substance can be used to make scientific and regulatory decisions concerning the other substance.
*Exemption* means an exemption from a testing requirement of a test rule promulgated under section 4 of the Act and part 799 of this chapter.
*Impurity* means a chemical substance which is uninitentionally present with another chemical substance.
*Joint sponsor* means a person who sponsors testing pursuant to section 4(b)(3)(A) of the Act.
*Joint sponsorship* means the sponsorship of testing by two or more persons in accordance with section
4(b)(3)(A) of the Act.
*Person* means an individual, partnership, corporation, association, scientific or academic establishment, or organizational unit thereof, and any other legal entity.
*Principal sponsor* means an individual sponsor or the joint sponsor who assumes primary responsibility for the direction of a study and for oral and written communication with EPA.
*Protocol* means the plan and procedures which are to be followed in conducting a test.
*Reimbursement period* refers to a period that begins when the data from the last non-duplicative test to be completed under a test rule are submitted to EPA and ends after an amount of time equal to that which had been required to develop data or after five years, whichever is later.
*Sponsor* means the person or persons who design, direct and finance the testing of a substance or mixture.
*Test substance* means the form of chemical substance or mixture that is specified for use in testing.
[49 FR 39782, Oct. 10, 1984, as amended at 51 FR 23712, June 30, 1986; 78 FR 72829, Dec. 4, 2013]