Respired air

Antoine-Laurent Lavoisier (1743—1794) followed up Priestley s work by making quantitative measurements of the ratio of oxygen to nitrogen in air. At first he named the new gas highly respirable air and later, vital air. Lavoisier is often considered the father of modern chemistry ... 

Inhalational anesthetics are administered in and, for the most part, eliminated via respired air. They serve to maintain anesthesia Pertinent substances are considered on p. 218. 

Lavoisier delivered two shocks to the Aristotelian elements. His experiments on water led him to conclude in 1783 that it is not a simple substance at all, not properly called an element, as had always been thought . And, concerning that other fluid element of antiquity, he announced that atmospheric air is composed of two elastic fluids of different and opposite qualities , which he called mephitic air and highly respirable air . Neither water nor air, in other words, is an element. 

Lavoisier then heated the mercury calx formed, collecting the gas produced. It proved to be the eminently respirable air, that is, Priestley s de-phlogisticated air. When this air was recombined with the vitiated or mephitic air,... 

Many additional experiments enable me to generalise this doctrine, and to declare that this pure and highly respirable air, is the constitutive principle of acidity, that this principle is common to all the acids. 

Respired air is saturated with moisture, after removal of which it contains normally some 4 per cent, of carbon dioxide and 16 to 17 per cent, of oxygen. These amounts vary both with the individual and with circumstances. Thus Thomson 3 found that the expired air of the average Manchester citizen contained 4 per cent, of carbon dioxide, whereas an average of 5 per cent, was observed in country districts,... 

Respired Air.—It has Jong been known that respired air is unsuitable to support human or animal life, and the question is—why ... 

These two factors working together are sufficient to show that respired air, being saturated with moisture at a warm temperature, cannot be wholesome, and L. E. Hill 6 and his co-workers regard the moisture content as the main cause of the discomfort of ill-ventilated buildings. 

Breathing zone A zone of air in the vicinity of an organism from which respired air is drawn. Personal monitors are often nsed to measnre pollntants in the breathing zone (USEPA, 1992a). 

Respirators protect the user in two basic ways. The first is by the removal of contaminants from the air. Respirators of this type include particulate respirators that filter out airborne particles and gas masks that filter out chemicals and gases. Other respirators protect by supplying clean respirable air from another source. Respirators that fall into this category include airline respirators that use compressed air from a remote source and self-contained breathing apparatus (SCBA) that include their own air supply. 

Kirwan articulated the identity and homogeneity of the inflammable air with phlogiston in some detail. Phlogiston was the principle of combustibility, the principle that gave metal its malleability and splendor, the principle that combined with vitriolic acid to form sulphur, and the principle that diminished respirable air. Inflammable air satisfied all of these criteria. It existed in many different states, depending on the portion of... 

Absorption of acetylene is driven by its partial pressure in respired air. Following inhalation, acetylene rapidly enters the blood by diffusion and is distributed to body organs in approximate proportion to their rate of perfusion. Acetylene crosses the blood-brain barrier, producing central nervous system effects characteristic of asphyxia. Diffusion is reversed upon the elimination of exposure and acetylene is excreted unchanged primarily via exhalation from the lungs, with some elimination via the urine. 

Methane is a flammable and colorless gas produced from organic wastes through bacterial action. It serves to displace oxygen in respirable air, thus producing oxygen starvation if present in high concentrations. 

Derivation (1) Gas for industrial use, carbon dioxide is recovered from synthesis gas in ammonia production, substitute-natural gas production, cracking of hydrocarbons, and natural springs or wells. For laboratory purposes it is obtained by the action of an acid on a carbonate. It is also a byproduct of the fermentation of carbohydrates and an end product of combustion and respiration. Air contains 0.033% of carbon dioxide (see greenhouse effect). (2) Liquid by compressing and cooling the gas to approximately —37C. (3) Solid (dry ice) by expanding the liquid to vapor and snow in presses that compact the product into blocks. The vapor is recycled. 

In a 1985-86 study, reported average ambient concentrations (combined particle- and vapor-phase) of eight PAHs in Denver ranged between 0.83 ng/m for benzojkjfluoranthene and 39 ng/m for phenanthrene (Foreman and Bidleman 1990). In a study conducted in Hamilton, Ontario, between May 1990 and June 1991, the concentrations of PAHs in respirable air particulate samples were... 

A primer in the proper use of respirators. Air purifying, air-line supplied, and self-contained breathing apparatus potential hazards to lungs and step-by-step procedures for selection, fitting, use, maintenance, and storage. Part of eight-volume series, Working in the Hazard Zone. ... 

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