less toxic substances for the more toxic substances being used. Personal protective
measures are not as effective as engineering controls (like ventilation) or work practice
modifications. Personal protective measures are limited to the use of protective clothing
and respirators. Medical control refers to programs encompassing pre-placement
physical examinations and medical surveillance of workers to detect early signs of
occupational disease.
b. Prevention of Occupational Dermatitis. The best prevention against
occupational dermatitis is to use measures that decrease, as far as possible, contact of
the workers with the dermatitis causing chemicals. When complete avoidance is
impossible, personal protective measures are used. These include protective clothing,
protective ointments, and personal cleanliness. Protective clothing should cover every
part of the body exposed to the irritating or hazardous chemical. This protective
clothing, and in some cases, underclothing, must be supplied and laundered daily.
Contaminated work clothing should never be worn away from the place of work. There
are many types of protective ointments available; when applied to the skin they form a
film that affords some protection. The main value of protective ointments comes from
the subsequent washing off, since the harmful chemicals are removed at the same time.
Personal cleanliness is the best protective measure against occupational dermatitis. If
strong irritant chemicals come into contact with the skin, they should be removed
immediately with water. Washing facilities should always be readily available. Pre-
placement and periodic medical examinations are recommended, to aid in the
prevention of occupational dermatitis.
c. Welding Fumes. Welding fumes vary in composition and quantity. They
depend upon the alloy being welded and the process, and the electrodes being used.
Therefore, for the analysis of these welding fumes to be accurate, consideration must
be made on the type of welding process performed and the system being inspected.
(1) Aluminum and titanium (little flame but intense radiation). For example,
when aluminum and titanium (a reactive metal and alloy) are welded in argon (a
protective, inert atmosphere), they will produce very little flame but intense radiation.
This radiation's can offspring into ozone.
(2) Steels (low-level fumes). When arc-welding steel, which is a similar
process to that of aluminum and titanium, fumes, produced is low level. These fumes
contain chromium and nickel compounds and the electrodes, coated and flux-cored with
fluorides, produce fumes containing considerably more fluorides than oxides.
(3) Ferrous alloys (considerable fumes). When arc-welding ferrous alloys in
an oxidizing atmosphere or environment, what is generated are significant amount of
fumes and carbon monoxide. These fumes are composed of different particles of
amorphous slag's containing silicon, iron, manganese, and other metallic components.
The alloy system used will determine the make up of the constituents.
MD0165
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