# 791.3 Definitions.
Terms defined in the Act, and not explicitly defined herein, are used with the meanings given in the Act.
(a) *The Act* refers to the Toxic Substances Control Act (TSCA) (15 U.S.C. 2601 *et seq.*).
(b) *The Agency* or *EPA* refers to the Environmental Protection Agency.
(c) *Byproduct* refers to a chemical substance produced without a separate commercial intent during the manufacture, processing, use or disposal of another chemical substance or mixture.
(d) *Dispute* refers to a present controversy between parties subject to a test rule over the amount or method of reimbursement for the cost of developing health and environmental data on the test chemical.
(e) *Exemption holder* refers to a manufacturer or processor, subject to a test rule, that has received an exemption under sections 4(c)(1) or 4(c)(2) of TSCA from the requirement to conduct a test and submit data.
(f) *Impurity* refers to a chemical substance unintentionally present with another chemical substance or mixture.
(g) A *party* refers to a person subject to a section 4 test rule, who:
(1) Seeks reimbursement from another person under these rules, or
(2) From whom reimbursement is sought under these rules.
(h) *Reimbursement period* refers to a period that begins when the data from the last non-duplicative test to be completed under a test rule is submitted to EPA and ends after an amount of time equal to that which had been required to develop that data or after 5 years, whichever is later.
(i) *Small business* refers to a manufacturer or importer whose annual sales, when combined with those of its parent company (if any) are less than $30 million.
(j) *Test rule* refers to a regulation ordering the development of data on health or environmental effects or chemical fate for a chemical substance or mixture pursuant to TSCA section 4(a).