Where:
R = the reimbursement share owed by company X.
C = the total cost of the testing required by the test rule.
Vx = the volume of the test chemical produced or imported by company X over the period defined by § 791.48 .
Vt = the total volume of the test chemical produced or imported over the period defined by § 791.48 .
40 C.F.R. §791.40