The environmental requirements for cleanrooms have become stricter as manufacturing processes need more stringent environmental conditions. The National Environmental Balancing Bureau (NEBB) developed and issued the first edition of Procedural Standards for Certified Testing of Cleanrooms (CPT) in October 1988. Since the standard’s first edition, there were two subsequent revisions: The second edition was issued in April 1996, and the third edition was issued in October 2009. Presently, NEBB is collaborating with the American National Standard Institute (ANSI) to issue a fourth edition of the CPT as an ANSI standard. The CPT standard committee is presently three years into the standard revision process. The following includes why testing standards are periodically updated, ANSI’s requirements for developing a standard, who would make a good standard committee member, what the current testing procedures entail, and the proposed changes to CPT.