Effect of carbon monoxide

Fig. 18. Inhibition effect of carbon monoxide on carbon monoxide conversion at 400°F over platinum. 100 ppm CaH8> 4.5% 02, 100 ppm NO.

In degreasing operations, there may be exposures to carbon monoxide, which may compound symptoms reported by workers (NIOSH 1973). Illnesses of certain employees, documented at a neighboring hospital, included headache, nausea, dizziness, and chest pain. The NIOSH report concluded that the first employee illness reports were due to toxic effects of carbon monoxide complicated by trichloroethylene exposure. The... 

Baldwin, R.C., Pasi, A., MacGregor, T.J. and Hine, C.H. (1975). The rates of radical formation fixjm the dipyridylium herbicides paraquat, diquat and morfemquat in homc nates of rat lung, kidney and liver an inhibitory effect of carbon monoxide. Tox. Appl. Pharmacol. 32, 298-304. 

Effect of Carbon Monoxide Partial Pressure on Isomeric Distribution of the Hydroformylation Products of Olefins (30)a... 

Phosphoric acid-based systems, for cellulosics, 11 488 Phosphoric acid esters, 24 159 Phosphoric acid fuel cells (PAFC), 13 858— 860 12 203-204, 216-219 19 626 effects of carbon monoxide and sulfur in, 12 219... 

Dodds RG, Penney DG, Sutariya BB. 1992. Cardiovascular, metabolic and neurologic effects of carbon monoxide and cyanide in the rat. Toxicol Ixtt 61(2-3) 243-254. 

The lethal effects of carbon monoxide on hemoglobin had been analyzed by Claude Bernard and shown to be due to the formation of an iron-carbonyl compound. In 1891 Mond and Langer showed that iron pentacarbonyl could be dissociated by light, and in 1897 J.S. Haldane and J.L. Smith found light would decompose the carbonyl compound of hemoglobin. Other metal carbonyls are not photodecomposed. 

As we saw with Mrs. Madison, the effects of carbon monoxide at relatively low atmospheric concentrations, such as 50 to 100 ppm, can be serious but are insidious in their onset so that the victim may not be aware of trouble until it is too late. These effects include headache, which may become severe and prolonged, nausea, dizziness, and weakness. As the condition develops, there will be mental confusion and ultimately unconsciousness, perhaps with convulsions. At lesser concentrations, of course, the effects will be less severe, while at high concentrations (for example, 0.3% to 0.4%) the effects can be dramatic, with rapid unconsciousness and death. 

X-PetUent + Cobalt Hydrocarbonyl—Effect of Carbon Monoxide 30 Minutes)... 

Glasson, W. A. Effect of carbon monoxide on atmospheric photooxidation of nitric oxide—hydrocarbon mixtures. Environ. Sci. Technol. 9 343-347, 1975. 

The combined effect of carbon monoxide and alcohol on odor sensitivity. Environment International 12,207-210. 

The possible effects of carbon monoxide on alfalfa canopies have also been tested but CO did not measurably depress CO2 uptake rates when present in concentrations ranging up to 80 ppm in the fumigant (3). 

The health effects of carbon monoxide are among the most thoroughly studied and best understood of any air pollutant. The risks posed by the gas (as for all pollutants) vary on the basis of two factors the concentration to which one is exposed and the length of time the exposure lasts. That is, the most dangerous conditions are those in which a person is exposed to large concentrations of carbon monoxide for long periods. A lesser risk is involved when the exposure is to lower concentrations of the gas for shorter periods. 

The primary health effect of nitric oxide results from its tendency to react with hemoglobin in red blood cells, in much the same way as carbon monoxide does. The concentration of nitric oxide is normally so low, however, that this effect is relatively minor, especially compared with the effects of carbon monoxide exposure. 

The mechanism most consistent with all the data is an ionic acid opening of the epoxide —apparently where the hydrocarbonyl is used as an acid to attack the epoxide— which is more sensitive to steric effects than to electronic factors. This conclusion may at first appear to be inconsistent with our previous finding that isobutylene reacted with cobalt hydrocarbonyl to give exclusively addition of the cobalt to the tertiary position. The inhibitory effect of carbon monoxide on that reaction, however, indicated that it was probably cobalt hydrotricarbonyl that was actually adding to the olefin and steric effects would be expected to be much less important with the tricarbonyl than with the tetracarbonyl (7) Apparently he feels now that the former reactions really involve the tricarbonyl, loss of CO being important to get the reaction running whereas epoxide attack perhaps involves a tetracarbonyl, steric factors are more important here. 

The health effects of carbon monoxide make it a primary air pollutant. The federal government has established national standards for CO to protect the general population from this toxic gas. The national standard is 9 ppm (parts per million) averaged over 8 hours or 35 ppm averaged over 1 hour. Table 23.1 summarizes the health effects associated with different CO concentrations. 

Whether the toxic effects are mainly due to anemic hypoxia or to the histotoxic effects of carbon monoxide on tissue metabolism is a source of controversy. Carbon monoxide will certainly bind to myoglobin and cytochromes such as cytochrome oxidase in the mitochondria and cytochrome P-450 in the endoplasmic reticulum, and the activity of both of these enzymes is decreased by carbon monoxide exposure. However, the general tissue hypoxia will also decrease the activity of these enzymes. 

Putz, V.R., Johnson, B.L. Setzer, J.V (1976) A comparative study of the effects of carbon monoxide and methylene chloride on human performance. J. environ. Pathol. Toxicol., 2,97-112... 

Effect of carbon monoxide on the oxygen affinity of hemoglobin. CO-Hb = carbon monoxyhemoglobin. 

Fig 5 Effects of carbon monoxide on human beings This chad can be considered only as a general guide because the percent of CO blood saturation will vary with exertion, excitement, fear, depth of respiration, anemia, and general physical condition of the individual... 

Methanators are usually used in the ammonia production line to guard the catalyst of the ammonia converters from the ill effect of carbon monoxide and carbon dioxide. This section includes precise models for different types of methanators using the dusty gas model with reliable kinetic expression and the results are compared with those of the simplified models (A) and (B). 

Bibbo, G.S., Benson, P.M. and Pantano, C.G., (1991), Effect of carbon monoxide partial pressure on the high-temperature decomposition of Nicalon fibre , J. Mater. Sci., 26(18), 5075-5080. 

Finally, palladium dispersion was found to decrease asymptotically from 9% (1 wt.% palladium content) to 0.5% (20 wt.% palladium content). The effect of carbon monoxide concentrations exceeding the equilibrium values of the water-gas shift reaction was studied in depth. With increasing time on-stream and deactivation of the catalyst (containing 1% palladium), the carbon monoxide concentration exceeded the equilibrium up to 18-fold. Even higher values were found for lower reaction temperatures. 

Effect of Carbon Monoxide on Reaction Rate. Figure 2 shows Xg0 vs. W/Fgg data at Pg = 2.0 kPa and at various values of Pgg. This graph is strikingly different from that shown in Figure 1. 

Effect of Carbon Monoxide on Nitric Oxide Reduction by Char, The effects of carbon monoxide on nitric oxide reduction by char was analyzed by changing the gas flow rate of the reactant and the ratio of concentration of carbon monoxide to nitric oxide at the inlet of the reactor. This ratio defined as a was chosen to be three extreme cases a = 4-W. 16, a = 47.8, and a 91.6-V98.9. The initial series of experiments were carried out for O 4-V. 6... 

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