A class 1 wormhole is a type of wormhole.
In 2375, while aboard the USS Voyager, Seven of Nine ordered the computer to perform a gravimetric scan of a recently discovered wormhole's interior. The scan was to reveal inconsistencies in the spatial gradient. After the scan, the computer identified the wormhole as being consistent with a regular, typical class 1 wormhole. (VOY: "Bliss")