| There are several methods to control hazardous | | | | chemicals or carcinogens. These hoods have a lift or |
| chemicals. The best method is to eliminate it; the next | | | | swing door for access at the front of the enclosure. |
| best solution is to substitute a less toxic or less | | | | Use the glove box for greater contaminant exposure |
| hazardous chemical for the one in use. If the | | | | control. During normal use, the hood can not be |
| substance in use cannot be engineered out and there | | | | opened; operations and manipulations are performed |
| is no way to prevent all harmful levels of exposure, | | | | by putting hands and arms into rubberized/flexible |
| then ventilation is used. The next best method is the | | | | gloves. Glove boxes are normally used when the risk |
| wear of personal protective equipment and, when | | | | of exposure to minute amounts of a hazardous |
| there is no way to control exposure, to regulate the | | | | substance can not be tolerated for the amount of time |
| amount of time an employee can be exposed to the | | | | it takes to complete a task. |
| chemical through administrative controls. A combination | | | | A commonly used local ventilation vacuum system is |
| of general ventilation (whole area air circulation) and | | | | the movable "elephant trunk." The exhaust intake is at |
| local ventilation is commonly employed. | | | | the end of a movable or fixed position intake system |
| Local ventilation is provided through vacuum air suction | | | | consisting of a hood over the generation point. |
| for removing vapors, gases, and particulates at the | | | | Examples of local ventilation at the generation point |
| source of the airborne contamination. It is a major | | | | include capture of airborne contaminants generated by |
| engineering control for removing hazardous chemical | | | | use of solvents, cutting oils, soldering and brazing |
| vapors, dusts, and fumes from the point of generation. | | | | materials. |
| The vacuuming action prevents the contaminant from | | | | For more information about the content of this article, |
| entering the worker's breathing zone or from entering | | | | consult Material Safety Data Sheets (MSDS)/Globally |
| general air. There are several types and many | | | | Harmonized System Safety Data Sheets (SDS), |
| applications of local ventilation systems. | | | | Section 8, "Exposure Control/Personal Protection." For |
| Use an enclosed hood when conducting chemical | | | | information about references, products, and solutions |
| experiments and pouring hazardous materials. These | | | | involving equipment systems to provide local ventilation, |
| types of enclosed hoods are called chemical fume | | | | click on this link to access the blog, "Using Local |
| hoods. They control vapor or particle generation during | | | | Exhaust Ventilation to Control Hazardous Chemical |
| pouring operations, involving highly reactive or corrosive | | | | Exposures. |