Chemical nuisance dusts

Excessive concentrations of nuisance dusts in the workroom air may seriously reduce visibility, may cause unpleasant deposits in the eyes, ears and nasal passages, or cause injury to the skin or mucous membranes by chemical or mechanical action per se or by the rigorous... 

SAFETY PROFILE A nuisance dust. Moderately toxic by ingestion. An eye irritant. Does not occur freely in nature, but is found as silicon dioxide (silica) and as various silicates. Elemental Si is flammable when exposed to flame or by chemical reacdon with oxidizers. Violent reactions with alkali carbonates, oxidants, (A1 + PbO), Ca, CS2C2, CI2, C0F2, F2, IF5, Mnp3, Rb2C2, FNO, AgF, NaK alloy. When heated it will react with water or steam to produce H2 can react with oxidizing materials. See also various silica entries, SILICATES, and POWDERED METALS. 

Calcium Carbide Chemical safety goggles and (for those exposed to unusually dusty operations) a respirator such as those approved by the U.S. Bureau of Mines for "nuisance dusts" Remove from further exposure and call a doctor. Flush with clean running water in an eye wash fountain for at least 15 minutes and get medical attention. 

Ferric Ammonium Citrate Approved respirator for nuisance dust, chemical goggles or face shield. Flush with water. Rush with water. 

Since these products are often manually handled during, for instance, swimming pool cleaning and maintenance, they must be converted into shapes with properties that avoid nuisance dust and enhance stability. The pure chemicals, which, as produced, may be very fine (e.g., sometimes precipitated), are often mixed with other components for specific performance. For example, Oxone can be blended with many additives, including sodium-sulfate, -carbonate (especially the dense version), -bicarbonate, -perborate, -tripolyphosphate, -metasUicate, tetrasodium pyrophosphate, citric-, malic-, and tartaric-acids and surfactants and fragrances. To maintain stability, all ingredients must be anhydrous or hold hydrated water tightly. 

PERSONAL PROTECTION wear impervious protective clothing, including boots, chemical-resistant gloves, lab coat, apron, or coveralls wear chemical safety goggles use hood or other local exhaust ventilation to maintain exposure below threshold limit value (TLV) for nuisance dust appropriate respirators are needed in areas where exposure would be above the permissible exposure level use self-contained breathing apparatus in unknown concentrations maintain eyewash baths and safety showers in work area. 

As discussed in Chapter 4, chemicals can be a nuisance or pose health risks if they become airborne as a result of inadequate process control, operation and maintenance malpractice, inadequate maintenance, incomplete understanding of the process etc. Hazards may arise if the oxygen concentration in the air fluctuates beyond its normal level of 21% by volume, and fire/explosion dangers may arise from the presence of flammable gases, vapours or dusts in the atmosphere. Thus air quality tests may be required for a variety of purposes such as ... 

When comparing the dust-borne concentrations of butyric acid and p-cresol with the odour thresholds it seems that the concentrations are too small to be relevant for an odour nuisance. However, if the dust is removed from the gas phase of the air from animal houses the odour disappears (39), (40), (14). This supports the opinion of HAMMOND et al. (40) that the odor is concentrated on the dust particles. The authors conclude from their data that the concentration of the two odorants butyric acid and p-cresol is about 4TO7 greater on an aerosol particle than it is in an equal volume of air. Thus, an aerosol particle deposited on the olfactory organ carries odour equivalent to a much greater volume of air (40). These considerations indicate that dust from animal houses should be taken into account in connection with odour emission/immission measurements not only by chemical analysis but by sensory evaluations using olfactometers without dustfilters, as well. 

Pelletization pe-b-to- za-shon (1942) n. Processing of pigments or other chemical products into very small, free-flowing beads, which eliminates the dust nuisance. 

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