Seed held over for more than nine months from the original date of certification shall not be recognized as certified. However, it shall be eligible for recertification provided a representative sample of regulation size be submitted and meets the standards for certification. If changes in certification standards have been made between the date of first certification of the seed and date of request for recertification so that the seed does not meet the new requirements, it can be recertified for a period of one year if it meets the standards under which it was previously certified.