Breathing mask
A breathing mask was a type of breathing apparatus worn over the face to allow species that did not breath the local atmosphere to breath their own supply. They were sometimes also used for medical purposes to supply a patient with special breathing gas.

The alien foreman of a trellium mining colony had to breathe with the help of a mask because the toxic fumes had destroyed his lungs. His workers (as opposed to the miners) of his species also wore similar masks, presumably as a preventive measure. ()

During a simulation in 2153, an oxygen mask was used by Jonathan Archer and Degra in order to recover from reactor coolant which leaked into a simulated Malosian cargo shuttle they were aboard. ()

In 2154, Persis distributed life-support masks to a group of Augments she was in and to their "father", Arik Soong. Persis was mindful that there weren't enough masks for them all, but Soong told her they didn't need masks. ()

At early talks for a Coalition of Planets, a Coridanite ambassador wore a breathing apparatus over most of his face. ()

In 2155, breathing masks were worn by an away team who traveled, in a , from  to the surface of Mars. Though Phlox briefly tried his mask on shortly prior to the mission, every member of the away team donned one of the masks once the shuttlepod had landed on the planet. They continued to wear them while journeying across the planet's surface, then took them off inside an airlock in Mars' verteron array. ()

In 2263 of the alternate reality,  wore a breathing mask while inside an advanced long-range torpedo he fired from the  into space and then piloted to the surface of nearby planet Altamid. ()

In 2266, an oxygen mask was worn by Simon Van Gelder when he arrived as a stowaway aboard the , beamed there in a box containing some research documents. As he climbed out of the box, he took off the mask and left it in the container. ()

Upon beaming down to the planet Gothos, a face mask was worn by every member of a landing party consisting of Doctor Leonard McCoy and Lieutenants Jaeger and DeSalle, as they expected the planet's surface to be stormy and virtually unbearable for life without oxygen and life support systems. The team took off their masks as they found the surface of Gothos was far different and comfortable than they had detected, with an atmosphere which was exactly the same as their own. ()

Zaranites typically wore special breathing masks. Such a mask was worn by each of at least three Zaranites who were serving aboard the  during the V'ger incident in the 2270s. ()

Other breathing masks were worn by Aamaarazan Federation councilors at the trial of James T. Kirk in 2286. ()

While performing repairs inside a class 9 nebula, the crew of the  was forced to wear breathing masks with converters due to a malfunction of the ventilation system. ()

Life support technology