9 CFR §105.2

If an infraction of a requirement of a product license is brought to the attention of the licensee by written notification thereof by Animal and Plant Health Inspection Service, a subsequent violation of similar nature occurring with the same licensed biological product within 6 months of the said written notification shall be primafacie evidence of willful violation and the license for the product shall be subject to suspension or revocation under the provisions of § 105.1(b).