26 U.S.C. § 6715: Dyed fuel sold for use or used in taxable use, etc.

any dyed fuel is sold or held for sale by any person for any use which such person knows or has reason to know is not a nontaxable use of such fuel, any dyed fuel is held for use or used by any person for a use other than a nontaxable use and such person knew, or had reason to know, that such fuel was so dyed, any person willfully alters, chemically or otherwise, or attempts to so alter, the strength or composition of any dye or marking done pursuant to section 4082 in any dyed fuel, or any person who has knowledge that a dyed fuel which has been altered as described in paragraph (3) sells or holds for sale such fuel for any use which the person knows or has reason to know is not a nontaxable use of such fuel, $1,000, or $10 for each gallon of the dyed fuel involved. In determining the penalty under subsection (a) on any person, paragraph (1) shall be applied by increasing the amount in paragraph (1)(A) by the product of such amount and the number of prior penalties (if any) imposed by this section on such person (or a related person or any predecessor of such person or related person). The term “dyed fuel” means any dyed diesel fuel or kerosene, whether or not the fuel was dyed pursuant to section 4082. The term “nontaxable use” has the meaning given such term by section 4082(b). If a penalty is imposed under this section on any business entity, each officer, employee, or agent of such entity who willfully participated in any act giving rise to such penalty shall be jointly and severally liable with such entity for such penalty. fraud or mistake in the chemical analysis, or mathematical calculation of the amount of the penalty.