Section 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME

WELDMASTER THORIATED TUNGSTEN TIG TIPS TT224

NFPA

PRODUCT USE

Alloyed tungsten electrode for gas/tungsten arc welding using direct current (DC electrode
negative). GTAW- TIG. Gas shielded with helium, argon or their mixtures.

SYNONYMS

"tungsten welding electrode", "thoriated tungsten electrode", "tungsten electrode", "TIG
welding", GTAW-TIG, "gas/tungsten arc welding", "automatic welding"

Section 2 - HAZARDS IDENTIFICATION

CANADIAN WHMIS SYMBOLS

EMERGENCY OVERVIEW

RISK

May cause CANCER.

POTENTIAL HEALTH EFFECTS

ACUTE HEALTH EFFECTS

SWALLOWED

  Accidental ingestion of the material may be damaging to the health of the individual.  If given orally, tungsten can accumulate in the spleen, kidney and liver. Symptoms of poisoning include diarrhea, stoppage of breathing and circulatory collapse leading to death. Loss of appetite, abdominal pain, incoordination, trembling and shortness of breath can occur; weight loss is also common.  

EYE

  Limited evidence or practical experience suggests, that the material may cause eye irritation in a substantial number of individuals. Prolonged eye contact may cause inflammation characterized by a temporary redness of the conjunctiva (similar to windburn).  alpha-Radiation produces severe inflammation of eyelid tissue and eye surface. There may be a delay of years before symptoms develop. Cataracts can develop an are progressive, but their growth may stop at any stage.  The dust may produce eye discomfort and abrasive eye inflammation.  

SKIN

  Skin contact with the material may damage the health of the individual; systemic effects may result following absorption.  There is some evidence to suggest that the material may cause mild but significant inflammation of the skin either following direct contact or after a delay of some time. Repeated exposure can cause contact dermatitis which is characterized by redness, swelling and blistering.  Skin contact is not thought to have harmful health effects, however the material may still produce health damage following entry through wounds, lesions or abrasions.  Entry into the blood-stream, through, for example, cuts, abrasions or lesions, may produce systemic injury with harmful effects. Examine the skin prior to the use of the material and ensure that any external damage is suitably protected.  The material may cause skin irritation after prolonged or repeated exposure and may produce on contact skin redness, swelling, the production of vesicles, scaling and thickening of the skin.  

INHALED

  Inhalation may produce health damage*.  The material is not thought to produce either adverse health effects or irritation of the respiratory tract following inhalation (as classified using animal models). Nevertheless, adverse effects have been produced following exposure of animals by at least one other route and good hygiene practice requires that exposure be kept to a minimum and that suitable control measures be used in an occupational setting.  Not normally a hazard due to non-volatile nature of product.  alpha-Radiation kills cells immediately adjacent to the source of contact. Damage may be irreversible. Generally, soluble compounds are more easily absorbed. Smaller particles can lodge and remain in the alveoli (air sacs); larger ones are more easily swallowed. Damage depends on the speed of elimination, susceptibility of tissue, and radioactive damage. Even a single dose may produce radiation sickness.  A whole body dose of 2-10 Gray may cause loss of appetite, tiredness, nausea and vomiting,  most severe after 6-12 hours. After this subsides a gross disturbance in blood cell distribution occurs with loss of white blood cells and platelets over weeks. The activity of bone marrow may become so depressed that overwhelming infections can occur and cause death. A dose of 4 Gray can lead to damage of the bowel lining, causing untreatable nausea, vomiting and diarrhea, which may result in severe dehydration, collapse and death. Although repair of the damage may occur, failure of blood cell production can ensue. At 6 Gray, damage to the blood cell production and digestive systems can be fatal. Whole body doses of 30 Gray can cause nausea, vomiting, listlessness, drowsiness, weakness, tremors, convulsions, inco-ordination and death within hours. The reproductive organs are particularly sensitive to radiation. A does of 0.3 Gray can cause temporary loss of fertility in men; there may be cessation of periods in women.  

CHRONIC HEALTH EFFECTS

  The effects of exposure to internally deposited alpha-emitters largely depends on the dose and target organs. Sufficiently high doses may produce radiation sickness. Possible disorders may include lung cancer, problems of sterility, anemia, leukemia or bone-  cancer. Leukemia and cataracts have been observed at doses lower than those which produce skin scarring and cancer or bone tumors. The lens of the eye should be considered as critical.  Limited evidence suggests that repeated or long-term occupational exposure may produce cumulative health effects involving organs or biochemical systems.  There is sufficient evidence to suggest that this materialdirectly causes cancer in humans.  Prolonged retention of thorium compounds in the body leads to long-term alpha- irradiation of the tissues. Symptoms only appear after a considerable length of exposure, and there are effects to the blood-forming, nervous and immune systems. The bones and the lung may be damaged. Thorium may cause cancer of the liver, throat, bronchi and kidney.  Natural radioactivity from the thorium oxide is considered to be well  below occupational exposure standards. Although thoria is released in  welding and exceeds the recommended threshold value of 0.9 alpha  disintegrations/(min)/m3 at a distance of 6 inches from the arc, levels  measured at the breathing zone of the welder were substantially lower than  this.  For cold, unused electrodes the exposure route is low level ionising  radiation from the thoria content. Anticipated dose rate on handling will  not exceed 7.5 micro Sievert per (working) hour. This means that the  Annual Limits of Intake by workers will not exceed the NOHSC Standard of  20 milliSievert per year as a 5 year average.