"The Sky is Falling, The Sky is Falling"
Sure its radioactive, but so are many other things.
Where do you draw the line? A group of men working along side of Highly explosive cylinders using high temperature flames and arcs. How many times have you seen an can of D-spat or some other Aerosol can on a welding table? Talk about hazords! They can go off like a bomb.
Tell the "Poor Shumk" that it is radioactive, tell every body, put up a sign, but leave the government out of it. Unless you want to have to go to the NRA every time you get an electrode.
Have you ever been in a Nuclear power plant? Ever try to GTAW with a pair of cotton gloves under a pair of rubber gloves under you leather gloves and then if you touch your hood and crap it up you have to leave it in the area, same applys to your glasses or wrist watch.
Some good sense can replace a lot of government. Like changing to Lanthinated tungston and there are others that are not radioactive.
I would trade all of my consumed smoke and fumes from welding and grinding nickel, chromium, zinc, molybdenum, and other alloys for the amount of low energy radiation absorbed via thorium bearing tungsten grinding.
You do have a point that certain types of health hazard are much less noticed than the all important, cause for termination issue of safety glasses under your welding hood.
Maybe that could be because when I go to the doctor for an eye injury I am working for the company that was paying me when I got injured. However if I have severe respiratory problems when I am 40 I may have worked for 100 different companies doing various types of work with supervisors that no longer work for that company for the same reasons I don't. And nobody is responsible.
Have a safe day
Gerald Austin
Weldinginspectionsvcs.com
The electrodes themselves present little threat of harmful radiation exposure to personnel. It's the fine airborne dust particulate, released by grinding and tip prep, which pose a threat of radioactive particles entering the body. So if your shop equipment is not properly ventilated it may be out of compliance, putting you at just about as much risk as your smucky coworker who puts the things in his mouth.
Regulations are indeed in place for thorium at both Federal and State levels. The best place for you to start is by obtaining an MSDS (Material Safety Data Sheet) from your electrode supplier.
http://www.tungsten.de/health.html#thorium <--This is what the Germans think
http://www.pro-fusiononline.com/tungsten/radioactivity.htm <--here is a balanced report given by a vendor of electrodes
Keep in mind whether alloyed with thorium or some other oxide, *Tungsten* itself produces irritant dusts during grinding, cutting and tip prep operations which are harmful to the respiratory system. Your shop management would demonstrate wisdom by employing the same fume/dust extraction methods for Lanthanum; Zirconium or Cerium alloyed electrodes as they do for thoriated electrodes.
Below is some well researched and authoritative information, Lifted from the fine website at (http://www.pro-fusiononline.com)
offering depth to our subject while specifically speaking to State, Local and International concerns.
I hope this will add some credibility to the opinions offered above.
To speak to the original post, we have learned that Thorium is regulated and
inhalation of Tungsten dust is to be avoided. Now you know it.
The burdan of responcibility falls squarely upon you, to share your newfound awareness,
to keep yourself safe and your shop and its personel in compliance.
Thoriated Tungsten Radioactivity
Background
For quite some time, tungsten manufacturers have added an oxide to pure
tungsten to improve the arc starting characteristics and the longevity of welding
electrodes. While 2% thoriated tungsten has been the most commonly used
tungsten material for many years, this electrode type is increasingly being
scrutinized because of concerns for the environment and for the safety of users of
this material. The concerns arise from the fact that the element thorium is
radioactive. On this basis, many organizations have evaluated alternative tungsten
types to see what changes in performance they would see by transitioning to
non-radioactive tungsten.
The Radioactivity Problem
The Thorium used in 2% thoriated tungsten is a radioactive element and therefore
can be dangerous to the health of those exposed to it and to the environment. It
is an alpha emitter, however when it is inside a tungsten electrode rod, it is
enclosed in a tungsten matrix and so there is little radiation emitted externally.
The main risk to the welder occurs in the ingestion of the material. This occurs
primarily during the inhalation of dust caused during grinding of tips for welding,
but also to a lesser extent during breathing of any fumes released during welding.
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:
1.It is recommended to work, if possible, without the use of welding electrodes
containing Thorium.
2.If this is not possible, precautions should be taken to protect employees
against the contamination with or the inhalation of grinding dust.
3.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."
"Toxicological Information: ...Heavy exposure to the dust or the
ingestion of large amounts of the soluble compounds produces changes
in body weight, behavior, blood cells, choline esterase activity and
sperm in experimental animals."
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