Respirator Cartridge Efficiency Studies: V. Effect of Solvent Vapor

Nelson, Gary O.; Harder, C.A.

doi:10.1080/0002889748507051

Cited by 56 publications

(24 citation statements)

References 3 publications

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“…It was observed that the breakthrough time of the NBC canister decreases with the increase of the vapour concentration of CCl 4 [15]. At inlet concentrations of 13.28, 26.56, 53.13, 106.26, 159.39, and 212.52 mg/L the breakthrough times were observed to be 82, 39, 19, 10.5, 7, and 5.5 min, respectively, at 30 lpm flow rate.…”

Section: Effect Of CCL 4 Concentration Test Flow Rate and Temperaturementioning

confidence: 80%

Breakthrough behaviour of NBC canister against carbon tetrachloride: a simulant for chemical warfare agents

Srivastava¹,

Shah²,

Mahato³

et al. 2012

Carbon letters

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A nuclear, biological, chemical (NBC) canister was indigenously developed using active carbon impregnated with ammoniacal salts of copper (II), chromium (VI) and silver (I), and high efficiency particulate aerosol filter media. The NBC canister was evaluated against carbon tetra chloride (CCl 4 ) vapours, which were used as a simulant for persistent chemical warfare agents under dynamic conditions for testing breakthrough times of canisters of gas masks in the National Approval Test of Respirators. The effects of CCl 4 concentration, test flow rate, temperature, and relative humidity (RH) on the breakthrough time of the NBC canister against CCl 4 vapour were also studied. The impregnated carbon that filled the NBC canister was characterized for surface area and pore volume by N 2 adsorption-desorption isotherm at liquid nitrogen temperature. The study clearly indicated that the NBC canister provides adequate protection against CCl 4 vapours. The breakthrough time decreased with the increase of the CCl 4 concentration and flow rate. The variation in temperature and RH did not significantly affect the breakthrough behaviour of the NBC canister at high vapour concentration of CCl 4 , whereas the breakthrough time of the NBC canister was reduced by an increase of RH at low CCl 4 vapour concentration.

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Section: Effect Of CCL 4 Concentration Test Flow Rate and Temperaturementioning

confidence: 80%

Breakthrough behaviour of NBC canister against carbon tetrachloride: a simulant for chemical warfare agents

Srivastava¹,

Shah²,

Mahato³

et al. 2012

Carbon letters

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“…Later, in the 1970s, Nelson et al reported [3][4][5] the effects of the above mentioned influencing factors on adsorption capacity of activated carbon for many kinds of organic vapor in detail. The measurements in their reports were carried out using both petroleum and coconut shell activated carbons for comparatively high concentrations of organic vapors (1,000 ppm).…”

Section: Introductionmentioning

confidence: 99%

“…Among these influencing factors, moisture content has been the focus of many quantitative researches, and there are many reports [1][2][3][4][5][6][7][8][9][10][11][12][13][14] regarding its effect on the gas filters of respirators or experimental packed beds of activated carbon at room temperature (approximately at 293-298 K).…”

Section: Introductionmentioning

confidence: 99%

Quantitative Evaluation of the Effect of Moisture Contents of Coconut Shell Activated Carbon Used for Respirators on Adsorption Capacity for Organic Vapors

2010

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Activated carbon is an elemental material used for hygienic applications, particularly as an adsorbent for harmful gases and vapors. In Japanese industrial and occupational hygiene, activated carbon produced from coconut shell is a traditional and popular adsorbent material due to its excellent adsorption ability and cost advantage. In this research, in order to clarify the effect of the preliminary content of moisture on the adsorption capacity in detail, we prepared several coconut shell activated carbons which were preconditioned by equilibration with moisture at different relative humidities. We measured their adsorption capacities as breakthrough times for 6 kinds of organic vapor, and attempted to determine the relationships between the relative weight increase of water adsorption and the decrease of adsorption capacities of the activated carbon specimens for the organic vapors. The procedure of the quantitative evaluation of the effect of moisture and the results are useful for practical applications of activated carbon, particularly those used as adsorbents in workplaces.

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“…In general, non-polar compounds, such as toluene and xylene, have strong adsorption affinity to charcoal, but for polar and/or highly volatile compounds, the adsorption affinity to charcoal is generally weak. In particular, the breakthrough volume for methanol is extremely small 1) . In workplaces where workers can be exposed to such vapors, the workers may use respirators, and in some instances, they must exchange the cartridge frequently in order to avoid exposure to such vapors.…”

mentioning

confidence: 99%

Thermal Reconditioning Characteristics of a Respirator Cartridge for Organic Vapors Using Humid Air as the Desorption Gas

Hori

Ishidao

Ishimatsu

2010

Journal of Occupational Health

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Thermal Reconditioning Characteristics of a Respirator Cartridge for Organic Vapors UsingHumid Air as the Desorption Gas: Hajime HORI, et al. Department of Environmental Management, School of Health Sciences, University of Occupational and Environmental HealthObjectives: Thermal reconditioning characteristics of organic vapors from a respirator cartridge were studied by introducing humid air into a cartridge that had adsorbed organic vapors in order to develop a thermal reconditioning method. Methods: Five different organic vapors (methanol, 2-propanol, acetone, dichloromethane and methyl acetate), most of which have relatively weak adsorption affinity to charcoal, were used in this study. Adsorption was carried out at a temperature of 25°C. The relative humidity of the adsorption air with organic vapor was 50%. When the vapor concentration in the downstream of the respirator exceeded the breakthrough concentration, that is, the occupational exposure limits in Japan, the vapor supply was stopped. Then, desorption was started by introducing clean humid air from opposite side of the cartridge under a heated condition. When the desorbed vapor concentration fell below the limit of quantification, desorption process was ended and the next adsorption cycle was started after the temperature had returned to room temperature. This adsorption -desorption cycle was repeated more than three times. The desorption temperature was 65°C and the relative humidity of desorption air was 20%, 50% or 70% at 25°C. Results: When the relative humidity was 20%, the breakthrough times of regenerated cartridges were shorter than that of a new one, but no difference was observed in the breakthrough curves when the relative humidity was greater than 50%. Conclusion: The results suggest that the thermal reconditioning of respirator cartridges using humid air is possible for these vapors. (J Occup Health 2010; 52: 125-131)

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Respirator Cartridge Efficiency Studies: V. Effect of Solvent Vapor

Cited by 56 publications

References 3 publications

Breakthrough behaviour of NBC canister against carbon tetrachloride: a simulant for chemical warfare agents

Breakthrough behaviour of NBC canister against carbon tetrachloride: a simulant for chemical warfare agents

Quantitative Evaluation of the Effect of Moisture Contents of Coconut Shell Activated Carbon Used for Respirators on Adsorption Capacity for Organic Vapors

Thermal Reconditioning Characteristics of a Respirator Cartridge for Organic Vapors Using Humid Air as the Desorption Gas

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