Hydrogen chloride vapor

Air emissions for processes with few controls may be of the order of 30 kilograms lead or zinc per metric ton (kg/t) of lead or zinc produced. The presence of metals in vapor form is dependent on temperature. Leaching processes will generate acid vapors, while refining processes result in products of incomplete combustion (PICs). Emissions of arsine, chlorine, and hydrogen chloride vapors and acid mists are associated with electrorefining. 

Hazards Perform the reaction in a well-ventilated area, as hydrogen chloride vapors are highly irritating to the nose and throat. 

Data on the absorption, distribution, metabolism, and excretion of hydrogen chloride are sparse. There are reports of severe nonlactic metabolic acidosis developing rapidly after ingestion of hydrochloric acid (suggesting systemic absorption from the gastrointestinal tract), but this effect has not been reported after dermal exposure to concentrated hydrochloric acid or after inhalation of hydrogen chloride vapor or aerosol. No studies were found on upper respiratory... 

The absorption (if any) of hydrogen chloride vapor and aerosol through intact human skin in vitro should be studied ... 

Solution The process described is neither flow nor batch, but semibatch in nature. However, with assumptions which are reasonably valid, the problem can be reduced to that for a constant-density batch reactor. If the density of the solution remains constant and the hydrogen chloride vaporizes and leaves the solution, the volume of the liquid-phase reaction will be constant. Then the relationship between the composition of the substances in the liquid phase is governed by rate expressions of the type used in this chapter. Assume that the reactions are second order. Then the rate of disappearance of benzene, determined entirely by the first reaction, is... 

HAZARD RISK Highly flammable combustion forms toxic vapors of phosgene, carbon monoxide and hydrogen chloride vapor/air mixtures are explosive caustic to metals present in water decomposes in water to produce hydrogen chloride and formaldehyde reacts with rubber readily hydrolyzed NFPA code not available. 

EXPLOSION and FIRE CONCERNS extremely flammable NFPA rating Health 3, Flammability 3, Reactivity 2 combustion may produce toxic gases and vapors, such as phosgene, carbon monoxide, and hydrogen chloride vapors are heavier than air and may travel to a source of ignition and flash back decomposes in water producing hydrogen chloride and formaldehyde vapor/air mixtures are explosive reacts with rubber readily hydrolyzed caustic to... 

Carefully neutralize spiUs of hydrochloric acid with a suitable agent such as powdered sodium bicarbonate, further dilute with absorbent material, place in an appropriate container, and dispose of properly. DUntion with water before applying the solid adsorbent may be an effective means of redncing exposure to hydrogen chloride vapor. Respiratory protection may be necessary in the event of a large spiU or release in a confined area. 

Figure 6.10 Effect of hydrogen chloride vapor on weight loss during pyrolysis of continuous filament high tenacity rayon fiber from Teijin Co. Source Adapted from Shindo A, Nakanishi Y, Soma I, Carbon Fibers from Cellulose Fibers, AppI Polym Symposia, No 9, 271-284, 1969.

Vapor contact with the eye will cause severe irritation experienced as pain in the eye, excess lachrymation, closure of the eyelids, and marked excess redness and swelling of the conjunctive. If high concentrations of hydrogen chloride vapor are formed, then comeal injury can occur. Splash contamination may cause severe conjunctivitis seen as marked excess redness and swelling of the conjunctive, discharge, iritis, and severe comeal injury. The comeal injury, if untreated, could result in permanent blindness. 

Repeated exposure of the skin to concentrated anhydrous hydrogen chloride vapor may result in bums or dermatitis. 

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