Welding Fume Isocyanates Basic Principles is Occupational Hygiene 2010

45 this study an excess of lung cancer was observed in small groups of workers with more than 30 years since first exposure to mineral wool, but there was no correlation between either the intensity or length of exposure and the excess of lung cancer. In fact, X-ray and lung function studies on current workers have not shown exposure to mineral wool to be associated with lung abnormality.

4.3 Welding Fume

Welding fume consists of mixtures of airborne gases and fine particles which if inhaled or swallowed may result in risks to health. The degree of risk will depend on: the composition of the fume, the quantity of fume in the air which is breathed, the duration of exposure. The main health effects are: Irritation of the Respiratory Tract: Gases or fine particles of fume can cause dryness of the throat, tickling, coughing, tightness of the chest and difficulty in breathing. Metal Fume Fever: The inhalation of many freshly formed metallic oxides, such as those of zinc, cadmium, copper etc may lead to acute flu-like illness termed metal fume fever. With the exception of exposure to cadmium fume serious complications are rare. The commonest cause of metal fume fever occurs from welding galvanised steel. Systemic Poisoning: This can result from the inhalation or swallowing of substances contained in welding fume such as fluorides, manganese, lead, barium and cadmium. The presence of these substances in the fume depends upon the welding process being used and the material being welded. Long Term or Chronic Effects: The inhalation of welding fumes can lead to the development of benign X-ray changes, referred to as Siderosis. A subject of current concern is whether welders have an increased risk of developing cancer as certain constituents of some welding fumes, such as hexavalent chromium and nickel may be carcinogenic. 46

4.4 Isocyanates

Isocyanates can be liquids or solids at room temperature and are mainly used in the production of polyurethanes, foams, adhesives, varnishes and paints. They are irritating to the skin and mucous membranes. However, the most serious problems associated with exposure to isocyanates are those affecting the respiratory system. Isocyanates are widely recognised as one of the commonest causes of occupational asthma. After varying exposure to isocyanates workers may respond to extremely low concentrations and this is known as respiratory sensitisation.

4.5 Wood Dust