16. HITSAUS- JA POLTTOLEIKKAUSTYÖT
Zinc and copper coatings
When heating zinc or copper coated steel hazardous fumes are produced and they can
cause a metal fume fever. The symptoms (fever, nausea, muscle pain and overall weakness)
can occur after a few hours of exposure. Symptoms that start in the evening are
usually gone by morning. Long term or combined effects are yet unknown.
Steel
80% of the fumes of unalloyed steel are Ferro oxides, silicates, alkali metals and
calcium compounds. Manganese compounds and fluoride compounds originating
from the alkali coated electrodes, and are even more hazardous, are present in low
percentages in the fumes and gasses.
In the fumes of stainless steel there might be chrome and nickel compounds that
are classified as causing a cancer risk. The risk is evaluated based on 6-chrome.
There is much less of 6-chrome in MIG and TIG welding than in rod welding. In Finland
welders working on stainless steel are yearly recorded in the ASA register (Register
on mployees Exposed to Carcinogens).
Aluminum
In aluminum welding, aluminum oxide is produced. Extended exposure may have hazardous
effects. Most of the aluminum leaves your body with in the urine, but some
residue is left in your organism. Therefore, people who continuously work with aluminum
welding should have regular urine specimens tested, unless these tests are proven
unnecessary based on work hygienic testing or other biological samples.
The brightness of glowing material and especially high voltages used in the welding of
thick materials cause strong ultraviolet radiation. Strong UV radiation separates oxygen
from the air forming ozone that can be recognized by its sharp smell. Ozone is a
gas that is dangerous for your lungs. The risk for exposure is the greatest in confined
and poorly ventilated spaces. Don’t forget to pay attention to your protective equipment
and good ventilation when welding aluminum.
The best way to prevent the effects of the fumes and gases produced in welding is
to use local ventilation. The worker creating the fumes is the one responsible for
arranging local ventilation. Plan the ventilation together with your supervisor.
An air-supplied respirator or a respirator with a dust filter will provide you even
better protection.
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