WELDING FUME GUIDES AND INFORMATION
REVISED TLV FOR MANGANESE
The American Conference of Governmental Industrial
Hygienists (ACGIH) advised in February 2013 that it had adopted the proposed change to the
Threshold Limit Value (TLV) for manganese. The change was published in the 2013 Edition of its
TLVs and Biological Exposure Indices (BEIs) publication.
TLV FOR CHROMIUM COMPOUNDS
The American Conference of Governmental Industrial
Hygienists (ACGIH) advised in March of 2018 that it had adopted its proposed change to the
Threshold Limit Values (TLVs) for Chromium Compounds. The change was published in the 2018
Edition of its TLVs and Biological Exposure Indices (BEIs) publication. The new TLV is 0.0002
mg/m3 for inhalable hexavalent chromium compounds, representing a 250-fold reduction from the
previous 0.05 mg/m3 TLV. The new TLV for chromium compounds includes a .003 mg/m3 limit for
inhalable chromium (III) compounds, which is a 167-fold reduction from the previous 0.5 mg/m3
TLV. These changes are not specific to the welding industry, but may impact welding and its
allied processes that contain chromium compounds and/or may contain chromium compounds in the
fume.
The ACGIH’s recent change in the chromium compounds
TLVs appears to be based primarily on animal studies for the hexavalent chromium TLV changes,
and studies of Finnish chromium workers for the chromium (III) compounds TLV change.
The ACGIH acknowledges that its TLVs are not
consensus standards and do not take into account economic or technical feasibility issues. The
ACGIH recognizes that that some governmental entities may utilize its TLVs in adopting
standards.
Where exposures are assessed to be over the TLV, many
approaches can be considered in the workplace for reducing exposure levels to contaminants to
levels below the TLV, including these new TLVs related to chromium compounds.
IARC CLASSIFICATION CHANGE STATEMENT
In August of 2018, the International Agency for Research on Cancer (IARC) published its Volume 118 Monograph, wherein they stated that they have determined that welding fumes and ultraviolet radiation from welding are carcinogenic to humans (Group 1). IARC had previously classified welding fumes as “possibly carcinogenic to humans,” Group 2B, in 1989. According to IARC, welding fumes cause cancer of the lung and positive associations have been observed with cancer of the kidney. Also according to IARC, ultraviolet radiation from welding causes ocular melanoma. IARC identifies gouging, brazing, carbon arc or plasma arc cutting, and soldering as processes closely related to welding.
The agency indicates in its monograph that the new classification is based on evidence from case studies and experimental research. According to the agency, cofounders such as asbestos exposure and tobacco use were determined to be inadequate to account for all of the excess risk indicated.
PUBLICATIONS FROM AMERICAN WELDING SOCIETY
Safety and Health Fact Sheets
Safety in Welding, Cutting and Allied Processes
Document - AWS/ANSI Z49.1
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