(d) Any lamp with quartz envelope since it can emit dangerous
ultraviolet rays.
(e) Germicidal lamps and other ultraviolet sources.
(2) All of the above sources can be dangerous when viewed directly
and are particularly hazardous when used in projector systems (collimnating
optics) or when filtered to reduce the visible spectrum.
The following
minimum precautionary measures must be followed;
(a) Do not view any high intensity source with the naked eye which
causes discomfort.
(b) Viewing of any high intensity infrared source without
protective eyewear is prohibited even though no discomfort is experienced.
The sensory system of the eye will not detect hazardous levels of infrared
e. Mercury Hazards.
Very small amounts of mercury can vaporize and
result in dangerous amounts of mercury vapor in the air.
A time-weighted
average (TWA) of 0.05 milligrams per cubic meter of air has been established
as acceptable. This is a time-weighted average concentration of mercury in
the air that would not be expected to cause illness in a worker breathing
this amount 40 hours a week for his working life.
If 2.5 milligrams of
mercury (a droplet of mercury the size of pinhead weighs about 1,000
milligrams) were vaporized in 100 cubic meters of air, the mercury
concentration of one-half of the TWA would be attained.
The mercury
contamination level in areas of frequent mercury use will be measured
monthly to assure that the TWA is not exceeded. Work surfaces and floors
where mercury is likely to be spilled should be smooth and free of cracks.
Mercury not in use will be stored in closed container to minimize spillage
and contamination. Personnel subject to handling or working around mercury
must exercise the following precautions:
(1) The mercury vapor detector will be placed in operation before
working with open containers of cold or hot mercury.
(2) Hot mercury will produce considerably more mercury vapor than
cold mercury.
(3) Eating, drinking, or smoking will not be permitted in the mercury
work areas. Wash hands before eating, etc.
(4) Personnel required to handle mercury shall wear three-quarter
length smocks (IL Federal supply catalog, C-8405/25-IL-A, FSC: 8415).
(5) Practice good housekeeping at all times to be sure that no small
droplets of mercury are allowed to remain undetected.
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