Re: [PHISH] RE: Tungsten,2% Thoriated or Pure?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Teslacoil Workshop" <workshop@xxxxxxxxxxxxx>

Stop laughing Bill...

This from a Welding Group:

The American Welding Society, in their A5.12 "Specification for Tungsten and
Tungsten-Alloy Electrodes for Arc Welding and Cutting" states the following
on this issue: "Thorium is radioactive and may present hazards by external
and internal exposure. If alternatives are technically feasible, they should
be used." They confirm that the primary concern in using this material is in
ingesting dust produced while grinding points on electrodes. They go on to
say:

...during the grinding of electrode tips there is generation of radioactive
dust, with the risk of internal exposure. Consequentially, it is necessary
to use local exhaust ventilation to control the dust at the source,
complemented if necessary by respiratory protective equipment.
Europe has also recognized the dangers of 2% thoriated tungsten. TWI (The
Welding Institute), which is the British equivalent of the AWS, reports that
"The British Health and Safety Executive (HSE) have issued an information
document to provide for the storage and use of thoriated tungsten
electrodes. This states that local exhaust ventilation should be provided
during the grinding operation, and that the dust from the grinding equipment
and the spent tips are disposed of in a sealed container to a landfill
disposal site." Further, "The HSE has recommended to factory inspectors
that, where thoriated tungsten electrodes are not necessary for the quality
of the weld, users should be encouraged to look for alternatives."

In a highly detailed study conducted by the DVS (the German Welding
Society), they measured the amounts of radioactive alpha particles and gamma
energy sprectra in the ambient air during the grinding of tungsten
electrodes. Some of the recommendations of this study included:

It is recommended to work, if possible, without the use of welding
electrodes containing Thorium.
If this is not possible, precautions should be taken to protect employees
against the contamination with or the inhalation of grinding dust.
The working area shall be cleaned regularly in order to avoid contamination
caused by deposited dust.
Another study was conducted in Germany by the State of Bavaria, Department
for Development and Environmental issues. They concluded that in facilities
where there is no dust extraction system for thoriated tungsten grinding,
the exposure to harmful particles is four times greater than with
extraction. However, even though dust collection provides a significant
improvement, levels may still be too high. In addition, they mentioned that
thoriated tungsten electrodes stored in boxes on a shelf do not seem to pose
any potential hazards. At the moment, a proposal has been placed before the
European Community Commission to drastically increase the severity of legal
regulations with respect to the use and disposal of thoriated electrodes.

In the State of California, tungsten manufacturers now include packaging of
2% thoriated tungsten electrodes that include a warning such as the one
Osram Sylvania uses, which is, "WARNING: This product contains or produces a
chemical known to the State of California to cause cancer. (California
Health and Safety Code 25249.5 et seq.)"

Finally, one of the major U.S. tungsten manufacturers, Teledyne Tungsten
Products, list the following cautions/warnings in their MSDS Sheets:

"Thorium is a naturally occurring low level radioactive element. Thorium is
primarily an alpha emitter. Daughters in the decay chain emit alpha, beta,
and gamma radiation. Radioactive elements are regulated by the Nuclear
Regulatory Commission. The NRC publishes regulations regulations regarding
radioactive materials."

"Effects of overexposure: ...Chronic inhalation of the dust may cause lung
damage in humans."
"Carcinogenic assessment: NTP-1 (Thoria). Note: NTP-1: Substances or groups
of substances that are known to be carcinogenic. 'Known carcinogens' are
defined by the NTP (National Toxicology Program) report as those substances
for which there is sufficient evidence of carninogenicity from studies in
humans to indicate a causal relationship between the agent and human
cancer."

Jeff speaking:

You guys want to be scientists... then BE scientists!!!!

Jeff