This is the 12457th most frequent Russian word.
кислородной
The Russian word "кислородной" means "oxygen-related" or "containing oxygen" in English.
Here, 'кислородной' (oxygen-based) is used as an adjective to describe the type of atmosphere being discussed.
Учёные обнаружили остатки кислородной атмосферы на далёкой планете.
Scientists discovered traces of an oxygen-based atmosphere on a distant planet.
In this case, 'кислородной' (oxygen) denotes the type of mask, indicating that it is equipped to provide oxygen.
Использование кислородной маски стало необходимым на большой высоте.
The use of an oxygen mask became necessary at high altitudes.
Here, 'кислородной' (oxygen) specifies the equipment's purpose or function, which is to manage or deliver oxygen.