2009 California Business and Professions Code - Section 20701-20702 :: Article 2. Certification Stamp

20701.  A certified industrial hygienist may obtain a stamp from an
industrial hygiene certification organization, which shall include a
number that uniquely identifies and bears the name of that certified
industrial hygienist. The stamp certifies that the industrial
hygienist has successfully passed an industrial hygiene examination
and met the certification maintenance requirements required and
approved by the industrial hygiene certification organization .

20702.  All reports, opinions, or official documents prepared for
submission to an employer, government agency, or other consumer by
any certified industrial hygienist shall be affixed by a stamp, as
specified in Section 20701, and signed by that certified industrial
hygienist.