happivapaita
Happivapaita is a term that appears rarely and is not part of standard Finnish vocabulary. The word is formed from happpi (oxygen) and vapaita (free of), yielding a literal "oxygen-free shirt." In current Finnish usage, happivapaita does not denote a defined garment or discipline, and there is no consensus on its meaning.
Possible interpretations include: as a conceptual idea in design or fiction; as a hypothetical technical term
Because there is no widely attested usage, references to happivapaita are limited and usually appear in informal
See also: oxygen, inert atmosphere, textiles, Finnish language.