The NYC Construction Codes designate third parties as Approved Agencies to perform tests or inspections of materials, equipment, construction related activities, and periodic maintenance. Approved Agencies must meet the qualifications of the Rules of the Department and should be regularly engaged in conducting tests or furnishing inspection services.

Inspection agencies evaluate building products for continuous compliance with applicable
standards through the listing period. These agencies are qualified to conduct periodic, unannounced, follow-up factory inspections. Inspection agencies will also have the authority to label products according to ISO guide 65. Inspection Agencies operating after July 1, 2008, must be accredited by the International Accreditation Service (IAS), or equivalent accreditation.

Read more at NYC.GOV or follow link below: http://www.nyc.gov/html/dob/html/model/approved_agencies_overview.shtml