(a) If, after an exemption takes effect, changes in circumstances,
including changes in law or policy, occur which call into question the
continuing validity of the Department's original conclusions concerning
the exemption,
the Department may take steps to revoke or modify the exemption.
(b) Before revoking or modifying an exemption, the Department will
publish a notice of its proposed action in the Federal Register and
provide interested persons with an opportunity to comment on the
proposed revocation or modification. In addition, the Department will
give the applicant at least 30 days notice in writing of the proposed
revocation or modification and the reasons therefor and will provide the
applicant with the opportunity to comment on the revocation or
modification.
(c) Ordinarily the revocation or modification of an exemption will
have prospective effect only.