[Milsurplus] Capacitor issues

[Nick England]

Not trying to re-hash the usual PCB merry-go-round, but this section from
"Radio Transmitters" by Gray and Graham (ITT) seems like reasonable advice -
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14-8. Chemical Hazards. Most chemical hazards associated with
radio transmitters occur as a result of failure or overheating of a
component.
   Insulating Oils. It is necessary to use nonflammable oils in
transformers,
capacitors, and other components which do not operate in a
concrete vault. These chemicals are usually chlorinated biphenyls.
Toxic fumes are liberated when this material is heated, and the maximum
safe concentration is 1.0 to 2.0 mg per cu m of air. Transformers and
chokes fitted with "breathers" should be vented to the outside. The
liquid can be absorbed through the skin; so hands should not be immersed
unless they can be washed fairly quickly afterward.
   Teflon. Teflon insulation releases vapors when heated to a point
above 400°F. It is not particularly dangerous, but inhalation can cause
an attack similar to influenza which has been called polymer fume fever.
Symptoms do not occur until several hours after exposure, and the attack
passes after 36 to 48 hr.
   Selenium. A selenium rectifier which has been overheated should be
approached with caution. The allowable concentration of selenium is
0.1 ppm in air. The material resembles arsenic both chemically and
physiologically. It causes respiratory irritation, abdominal pain, and
irritation to the brain (27).
   Carbon Tetrachloride. Carbon tetrachloride is frequently used for
maintenance purposes and is a dangerous chemical at room temperature.
The maximum allowable concentration in air is 25 ppm. It causes eye
inflammation and damage to the liver, kidneys, heart, and nervous
system. Absorption of 3 to 4 ml can be fatal. The toxic symptoms may
not appear until 2 to 8 days after exposure.
===================================
This generally useful book is at
http://www.introni.it/pdf/Gray%20-%20Graham%20-%20Radio%20Transmitters%201961.pdf

Nick England K4NYW
www.navy-radio.com
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