from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Not fit for breathing; not respirable.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Unbreathable.
from the GNU version of the Collaborative International Dictionary of English
- adj. Unfit for respiration; not having the qualities necessary to support animal life.
from The Century Dictionary and Cyclopedia
- Not respirable; unfit for respiration: as, an irrespirable atmosphere.
Sorry, no etymologies found.
 The burning of sulphur produces sulphurous acid, which is an irrespirable gas.
But this refers only to crude acetylene undiluted with air; and being a hydrocarbon -- being in fact neither oxygen nor common air -- acetylene is irrespirable of itself though largely devoid of specific toxic action.
After Baudrimont, insects are, in presence of alcohols, chloroform, and irrespirable gases, similarly affected as man.
In 1772, Priestley, after discovering that the sojourn of animals in a confined atmosphere renders it irrespirable, investigated the influence of plants placed in the same conditions, and he relates, in these words, the discovery that he made on the subject:
Those who had secured the shelter offered by the solitary marquee and who, notwithstanding the irrespirable and filthy atmosphere, considered possible suffocation and the danger of fire to be preferable to the drenching rain, were confronted with a new and far more terrifying menace.
Its especial sphere of usefulness is in severe cases of electric shock, hanging, smoke asphyxia, strangulation, suffocation, thoracic or abdominal pressure, apnea, acute traumatic pneumothorax, respiratory arrest from absence of sufficient oxygen, or apnea from the presence of quantities of irrespirable or irritant gases.
When pure, carbonic dioxide gas will instantly extinguish flame, and is perfectly irrespirable, causing the epiglottis to close spasmodically and producing immediate death by asphyxia.
If carbonic dioxide had been a pungent or corrosive gas, coal could not have been used as fuel; for its combustion, like that of sulphur, would soon have rendered the air irrespirable.
The abstract ideas of which the air consists, indispensable for life, but irrespirable by themselves, as it were, and only active in their re-directing function.
May the ghosts of the men who mar the earth, turning her sweet rivers into channels of filth, and her living air into irrespirable vapours and pestilences, haunt the desolations they have made, until they loathe the work of their hands, and turn from themselves with a divine repudiation.