Precautions confined spaces

Confined space precautions — Assess limited work spaces and slipping hazards, and evaluate hazardous atmospheres and interior surfaces for flammabihty, combustibility, or toxic fumes that could result from welding processes. 

Formic acid is combustible (flash point = 69° C), but the explosive ha2ard is considered slight. The decomposition to CO requires appropriate precautions to be taken when entering tanks or other confined spaces that have contained the acid. 

The special precautions appropriate for entry into confined spaces are summarized in Chapter 13. In fires, evacuation of burning buildings, prohibition on re-entry and the use of self-contained breathing apparatus by fire-fighters are key precautions. 

Chemical. Where severe chemical contamination is suspected, specific precautions must be followed if OSH A action levels are approached. Such instances rarely occur in LAQ investigations. One possible exception might be a pesticide spill in a confined space. In this case, an appropriate respirator and disposable coveralls may be needed. 

Before entry is allowed into a vessel or other confined space, the vessel should be isolated from sources of hazardous material by slip-plating or physically disconnecting all pipelines and by isolating all supplies of electricity, preferably by disconnecting the cables. On the whole, these precautions seem to be followed. Accidents as the result of a failure to isolate are less common than those resulting from a failure to remove hazardous materials or from their deliberate reintroduction as described in Sections 11.1 and 11.2. However, the following are typical of the accidents that have occurred. 

Confined space, See also Permit-to-Work system definition, 12 entry, 135, 417, 420 hazards, 151, 417 legislation, 417 precautions, 418, 419... 

The powder is spread on cotton muslin stretched over wooden frames and placed on the shelves. The drier is then closed and the vacuum pump set in motion. The pump usually operates a pressure of 100-150 mm Hg. When the pressure becomes steady, the screws clamping the lids are released, but the lids continue to adhere hermetically to the drier, owing to the reduced pressure created inside. As a safety precaution the driers work in this manner until drying has been completed. Thus should ignition occur the lids are freely detached. This prevents thepowder from burning in a confined space, and exploding, and so destroying the drier. The capacity of the... 

Detector tubes are convenient, low cost items but a technician should remember they are estimation devices. They cannot be used for some types of permitting applications, such as Confined Space Entry. Take the following precautions when using detector tubes. 

Liquid feed can be put into any downcomer of a tray column and feed points can therefore be installed after the column has been designed and erected. One precaution that needs to be taken in their use is that the feed may be raised to a comparatively high temperature in a confined space. If the feed contains hard water, the hardness may be laid down as scale, eventually blocking the downcomer. If the feed contains an inorganic solute it also may be deposited if the water in the feed flashes off. 

Ventilation in this confined space alone will control its atmospheric hazards at safe levels. A confined space can t be classified as a CACS if it has a physical hazard (unless that hazard has been isolated). Fewer precautions are needed to ensime the safety of its employers than for PRCSs. However, more precautions are needed to ensm e the safety of its employees than for a Isolated-Hazard Confined Space. 

Some confined spaces can be ventilated naturally. This is the case with most excavations. However, any time a naturally ventilated confined space is occupied, adequate precautions must be taken to prevent employee exposure to atmospheres containing less than 19.5 percent oxygen or to other hazardous atmospheres. Confined spaces that cannot be ventilated naturally must be ventilated with mechanical equipment. 

Had not trained the employees in confined space hazards and precautions, and the protective and emergency equipment required for work in confined spaces. 

Know confined space welding precautions. Confined spaces include manholes, tunnels, trenches, and pits. Monitor for hazardous atmospheres and check interior surfaces for toxic materials. 

If there are to be heated processes, such as open flames, welding and cutting, in a confined space, there is a need to take precautions for fire protection and removal of smoke and fumes. If workers are to use solvents for cleaning, they must be aware of the hazards of the solvents. Precautions must be in place. Electrical equipment should use low voltage. 

Activities in a confined space may create noise, ionizing radiation, heat or cold hazards. Planning for work in a confined space must identify and implement necessary precautions. 

Where work has to be done in a confined space (s. 30) such as a chamber, vat, pit, pipe or flue, the following precautions must be taken. 

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