Exposure to Fibres, Crystalline Silica, Silicon Carbide and Sulphur Dioxide in the Norwegian Silicon Carbide Industry

Abstract

Objectives: The aim of this study was to assess personal exposure to fibres, crystalline silica, silicon carbide (SiC) and sulphur dioxide in the Norwegian SiC industry.Methods: Approximately 720 fibre samples, 720 respirable dust samples and 1400 total dust samples were collected from randomly chosen workers from the furnace, processing and maintenance departments in all three Norwegian SiC plants. The respirable dust samples were analysed for quartz, cristobalite and non-fibrous SiC content. Approximately 240 sulphur dioxide samples were collected from workers in the furnace department.Results: The sorting operators from all plants, control room and cleaning operators in Plant A and charger, charger/mix and payloader operators in Plant C had a geometric mean (GM) of fibre exposure above the Norwegian occupational exposure limit (OEL) (0.1 fibre cm 23 ). The cleaner operators in Plant A had the highest GM exposure to respirable quartz (20 mg m 23). The charger/mix operators in Plant C had the highest GM exposure to respirable cristobalite (38 mg m 23 ) and the refinery crusher operators in Plant A had the highest GM exposure to nonfibrous SiC (0.65 mg m 23 ). Exposure to the crystalline silica and non-fibrous SiC was generally low and between 0.4 and 2.1% of the measurements exceeded the OELs. The cleaner operators in Plant A had the highest GM exposure to respirable dust (1.3 mg m 23) and total dust (21 mg m 23 ). GM exposures for respirable dust above the Norwegian SiC industry-specific OEL of 0.5 mg m 23 were also found for refinery crusher operators in all plants and mix, charger, charger/ mix and sorting operators in Plant C. Only 4% of the total dust measurements exceeded the OEL for nuisance dust of (10 mg m 23 ). Exposure to sulphur dioxide was generally low. However, peaks in the range of 10-100 p.p.m. were observed for control room and crane operators in Plants A and B and for charger and charger/mix operators in Plant C.Conclusion: Workers in the SiC industry are exposed to a mixture of several agents including SiC fibres, quartz, cristobalite, non-fibrous SiC and sulphur dioxide. Exposure levels were generally below the current Norwegian OELs; however, high exposure to fibres and respirable dust still occurs in the furnace department.

Increased Decline in Pulmonary Function Among Employees in Norwegian Smelters Reporting Work-Related Asthma-Like Symptoms

“…Current occupational exposure was assessed using a quantitative job exposure matrix that was constructed as the geometric mean of total dust exposure in each job category in each smelter, and is explained in detail elsewhere. 1,2 Briefly, dust from the working atmosphere was collected using personal samplers during the study period. The geometric mean of the dust exposure for the corresponding job title of the previous year was allocated to each employee.…”

“…These manufacturing processes emit several air pollutants into the workplace environment, including particulates and gases that are potentially harmful to airways. 1,2 Factory workers are exposed to particles of the raw materials that are characteristic of each production type (ie, substances containing silicon, iron, manganese, chrome, and titanium) as well as minerals composed of these elements, such as quartz. Other exposures include particles and gases originating from combustion in the furnaces, mainly carbon-containing dust that is contaminated by impurities of the anode, such as sulfur and other trace elements.…”

Experimental Evaluation of Respirable Dust and Crystalline Silica Controls During Simulated Performance of Stone Countertop Fabrication Tasks With Powered Hand Tools

“…No cristobalite was found in the cup grinding or polishing samples. Cristobalite is known to be formed at high temperature in the Acheson furnace SiC production process (Foreland et al, 2008), so it seems likely that dust abraded from the grinding wheel was the source of the cristobalite.…”

Accident and disease prevention in working life: Common grounds and areas for mutual learning

“…The processes are often old and physically relatively simple, but produce large amounts of pollutants. In the silicon carbide industry the cancer risk have been documented since 2000 (Romundstad, Andersen, & Haldorsen, 2001), and the dust exposure is documented to contain both fibers (Bye, Eduard, Gjonnes, & Sorbroden, 1985) crystalline silica, silicon carbide (SiC) and sulphur dioxide (S. Føreland, Bye, Bakke, & Eduard, 2008). The workers in this industry is heavily loaded by personal protective equipment using dust mask, CO alarm, eye protection, hearing protection, safety helmet, gloves and safety clothes.…”