Also known as ITS, Warnock-Hersey

Like UL, ITS' divisions Warnock Hersey and ETL test products for compliance with recognized standards, mostly ASTM and NFPA. Their single directory contains all types of construction products. Although ITS is less well known than UL, their testing laboratories are widely accredited and sometimes their listings suit specific applications better than UL listings. The Warnock Hersey and ETL certification marks are by ITS. Has better coverage of West Coast and Canadian manufacturers than UL.

SpecLink does not reference the ITS Directory itself, but instead offers the option of requiring products to be ITS or Warnock-Hersey Listed or Labelled, as appropriate.