Airborne contaminants mists

Airflow Systems, Inc Resource for the collection and filtration of dust, smoke, mist, fumes and other airborne contaminants generated during industrial and commercial manufacturing and processing applications. http., llwww.air, flowsvstems. com... 

Among the major potential hazards affecting working environment are chemical (airborne contaminants), biological, and physical hazards,. ir contaminants are commonly classified as either particulate contaminants or gas and vapor contaminants. Common particulate contaminants include dusts, fumes, mists, aerosols, and fibers. 

This Chapter provides information on available certified reference and quahty control materials relevant for use in the measurement of airborne contaminants in occupational hygiene. The majority of measurements made in this area worldwide are solvents, dust (total, respirable), elements, oil mist, quartz, fiber identification (asbestos, man-made fibers), mists and gases. 

Oil mist is a very common airborne contaminant in work place atmospheres where process machinery is cooled or lubricated with industrial grade lubricants. 

Substances with high vapor pressures tend to volatilize more quickly and can reach higher maximum air concentrations than substances with low vapor pressures. Some substances have such low vapor pressures that airborne contamination is a threat only if they are finely dispersed in a dust or mist. 

Local exhaust refers to any method designed to capture airborne contaminants nearest the point of generation or release. The system should draw the contaminant away from a person s breathing zone. Mechanical exhaust dilutes contaminated air and lowers the concentration of a hazardous substance. The effectiveness depends on the number of air changes per hour. A fume hood or fume removal system can capture hazardous air contaminants such as vapors, dusts, mists. 

Particulates Particulates include dusts, fumes, smoke, aerosols, and mists. Particulates also have classifications by size and chemical makeup. Shape can also be important. For example, some particulates have long, thin, fibrous shapes. Others may be spherical and have a fairly imiform cross-section. Figure 25-5 (Chapter 25) provides size characteristics of some airborne contaminants. 

Airborne contaminants such as dust and oil mists must be controlled so that they do not affect the final bond in any significant way. These factors can be more insidious than those of temperature and moisture, but can be just as damaging. 

Inhalation involves those airborne contaminants that can be inhaled directly into the lungs and can be physically classified as gases, vapors, and particulate matter that includes dusts, fumes, smokes, and mists. Inhalation, as a route of entry, is particularly important because of the rapidity with which a toxic material can be absorbed in the lungs, pass into the bloodstream, and reach the brain. Inhalation is the major route of entry for many hazardous chemicals in the work environment. 

MIST Produced by hot VAPORS that cool and condense at room temperature, an airborne contaminant. 

Ocular Effects. Effects on the eyes due to direct contact of the eyes with airborne mists, dusts, or aerosols or chromium compounds are described in Section 2.2.3.2. An extensive epidemiological survey was conducted of housewives who lived in an area of Tokyo, Japan, in which contamination from chromium slag at a construction site was discovered in 1973. The housewives included in the study were those who lived in the area from 1978 to 1988, and controls included housewives who lived in uncontaminated areas. Questionnaires, physical examinations, and clinical tests were conducted annually. Higher incidences of subjective complaints of eye irritation were reported by the exposed population than the control population in the early years of the survey, but in later years the difference between the two groups became progressively less (Greater Tokyo Bureau of Hygiene 1989). 

A system of local or general exhaust is recommended to keep employee exposures below the airborne exposure limits. Local exhaust ventilation is generally preferred because it can control the emissions of the contaminant at its source, preventing dispersion of it into the general work area. If the exposure limit is exceeded, a half-face dust/mist respirator may be worn for up to ten times the exposure limit or the maximum use concentration specified by the appropriate regulatory agency or respirator supplier, whichever is lowest. A full-face piece dust/ mist respirator may be worn up to 50 times the exposure limit, or the maximum use... 

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