What are the potential dangers to welders from the welding process, in particular, stainless steel welding?
Chromium is a naturally occurring element found in stainless steel, electrodes, and filler metals. These materials are all commonly used in welding processes. During welding, the intense heat turns this metal into a gas.
This gaseous form of chromium is known as hexavalent chromium, and has serious health risks for individuals exposedIn fact, hexavalent chromium (also referred to as Cr(VI)) is a well-established occupational carcinogen associated with lung cancer and nasal and sinus cancer.
- lung cancer in workers who breathe airborne hexavalent chromium;
- irritation or damage to the nose, throat and lungs (respiratory tract) if hexavalent chromium is inhaled; and
- irritation or damage to the eyes and skin if hexavalent chromium contacts these organs.
Workers can inhale airborne Cr(VI) as a dust, fume or mist while, among other things, producing chromate pigments, dyes and powders (such as chromic acid and chromium catalysts); working near chrome electroplating; performing hot work and welding on stainless steel ….” P. 5.
By 1998, there was sufficient scientific evidence and human studies available for EPA to issue its Toxicological Review of Hexavalent Chromium (EPA 1998), which observed that the published study of Cohen et al. (1974) had found nasal irritation, nasal septal ulceration and perforation, and nasal tissue damage associated with workers employed for more than 1 year and who had exposures to hexavalent chromium at certain (small) levels.
How is a stainless steel welder subjected to hexavalent chromium?
“Most of the materials in the welding fume comes from the consumable electrode, which is partially volatilized in the welding process; a small fraction of the fume is derived from spattered particles and the molten welding pool (Palmer and Eaton, 2001). The electrode coating, shielding gases, fluxes, base metal, and paint or surface coatings also contribute to the composition of the welding aerosol. Components of the source materials may be modified, either thermochemically in the welding zone or by photochemical processes driven by ultraviolet light emitted during welding. Vaporized metals react with air, producing metal oxides that condense and form fume consisting of particles that are primarily of respirable size.” HEALTH EFFECTS OF WELDING, James M. Antonini, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road (M/S 2015), Morgantown, WV, 26505, published in Critical Reviews in Toxicology, 33(1):61-103 (2003)
What are other ways a worker might be exposed to hexavalent chromium:
• chromate pigments in dyes, paints, inks, and plastics
• chromates added as anti-corrosive agents to paints, primers and other surface coatings
• chrome plating by depositing chromium metal onto an item’s surface using a solution of chromic acid
• particles released during smelting of ferrochromium ore
• fumes from welding stainless steel or nonferrous chromium alloys
• impurity present in portland cement.
What are the primary effects associated with exposure to hexavalent chromium?
“The primary effects associated with exposure to chromium (VI) compounds are respiratory, gastrointestinal, immunological, hematological, reproductive, and developmental. In addition, dermal and ocular irritation may occur from direct contact. Based on available dose-response data in humans and animals, the most sensitive noncancer effects of chromium(VI) compounds are respiratory (nasal and lung irritation, altered pulmonary function), gastrointestinal (irritation, ulceration and nonneoplastic lesions of the stomach and small intestine), hematological (microcytic, hypochromic anemia), and reproductive (effects on male reproductive organs, including decreased sperm count and histopathological change to the epididymis).
ATSDR “TOXICOLOGICAL PROFILE FOR CHROMIUM” (2012) –
Have you been exposed to hexavalent chromium and diagnosed with lung cancer?
Do you perform stainless steel “arc welding,” including (1) “stick welding” (that uses covered stainless steel electrodes) or do you routinely perform
(2) “MIG welding” (that uses stainless steel welding wire – either bare wire or flux cored wire) and, have you suffered or been diagnosed with the symptoms above?
There are many metal fabrication shops and industries in Alabama that fabricate or manufacture stainless steel items.
If so, call Greg Reeves today at 256-355-3311.
For additional information:
Am J Ind Med. 2000 Aug;38(2):115-26.
Lung cancer among workers in chromium chemical production.