Emergency planning and the acute toxic potency of inhaled ammonia.

Abstract

Ammonia is present in agriculture and commerce in many if not most communities. This report evaluates the toxic potency of ammonia, based on three types of data: anecdotal data, in some cases predating World War 1, reconstructions of contemporary industrial accidents, and animal bioassays. Standards and guidelines for human exposure have been driven largely by the anecdotal data, suggesting that ammonia at 5,000-10,000 parts per million, volume/volume (ppm-v), might be lethal within 5-10 min. However, contemporary accident reconstructions suggest that ammonia lethality requires higher concentrations. For example, 33,737 ppm-v was a 5-min zero-mortality value in a major ammonia release in 1973 in South Africa. Comparisons of secondary reports of ammonia lethality with original sources revealed discrepancies in contemporary sources, apparently resulting from failure to examine old documents or accurately translate foreign documents. The present investigation revealed that contemporary accident reconstructions yield ammonia lethality levels comparable to those in dozens of reports of animal bioassays, after adjustment of concentrations to human equivalent concentrations via U.S. Environmental Protection Agency (EPA) procedures. Ammonia levels potentially causing irreversible injury or impairing the ability of exposed people to escape from further exposure or from coincident perils similarly have been biased downwardly in contemporary sources. The EPA has identified ammonia as one of 366 extremely hazardous substances subject to community right-to-know provisions of the Superfund Act and emergency planning provisions of the Clean Air Act. The Clean Air Act defines emergency planning zones (EPZs) around industrial facilities exceeding a threshold quantity of ammonia on-site. This study suggests that EPZ areas around ammonia facilities can be reduced, thereby also reducing emergency planning costs, which will vary roughly with the EPZ radius squared. Images Figure 1 Figure 2

Room Temperature Ammonia Gas Sensing Using MnO<sub>2</sub>-Modified ZnO Thick Film Resistors

“…If the film surface chemistry is favorable for adsorption, the response and selectivity would be enhanced. The oxygen adsorption is poor for pure ZnO and shows poor response to NH 3 . In addition to this, ZnO requires relatively larger operating temperature to adsorb the oxygen ions, and therefore it would have responded at higher operating temperature.…”

“…A leak in the system can result the health hazards. Ammonia is harmful and toxic [1][2][3][4][5] in nature. Therefore all industries working on and for ammonia should have an alarm system detecting and warning for dangerous ammonia concentration levels.…”

Multi-objective evolutionary emergency response optimization for major accidents

“…Many serious accidents involving ammonia have been reported in the literature [60]. The scenarios considered correspond to different release rates and different wind direction: (1) 264 kg/s release rate of ammonia and release duration of 600 s (scenario 1) [24], and (2) 72 kg/s release rate of ammonia and release duration of 20,000 s (scenario 2) [60].…”

“…Many serious accidents involving ammonia have been reported in the literature [60]. The scenarios considered correspond to different release rates and different wind direction: (1) 264 kg/s release rate of ammonia and release duration of 600 s (scenario 1) [24], and (2) 72 kg/s release rate of ammonia and release duration of 20,000 s (scenario 2) [60]. With an appropriate model [48][49][50], we calculate the concentration of ammonia (gas heavier than air) as a function of time, as well as the arrival and the passage time of the plume at every point of the area.…”

Gas sensing properties of semiconducting copper oxide nanospheroids

“…It is harmful to human health and causes chronic lung diseases [1]. A minor leak of ammonia gas in the system may be hazardous to the industrial workers and thus its detection and monitoring are of immense importance in the early stages of the leakage at room temperature in a reproducible manner.…”