BACKGROUNDFew studies have investigated the impact on olfactory functioning of occupational exposure to toluene, an industrial solvent used in paints and cleaning fluids. The estimated olfactory dysfunction prevalence is 0.5-5%. Patients frequently do not complain about olfactory dysfunction. However, occupational exposure to chemicals may affect workers' health and safety, because of their continuous inhalation. This study aimed to examine the relationship between toluene exposure and olfactory dysfunction in furniture workers. METHODSThis was a cross-sectional study involving 65 workers. Data collection was by observation and interview on demographic characteristics, history of habits, and symptoms of chronic rhinitis. Risk of exposure scores were evaluated from potential hazard, exposure level, duration of employment, type of work, use of masks, ventilation of work space, and education and training. Olfactory function was tested using Sniffin' Sticks, and determination of environmental toluene level was by personal sampling. The odds ratio was used to test correlations between variables. RESULTSOnly 44 subjects could be analyzed, 37 (84.1%) of whom had olfactory dysfunction. Workers with high toluene exposure had a significantly 12.5-fold risk of olfactory dysfunction in comparison with those with low exposure (OR=12.5; CI 95% 1.35 -115.79). CONCLUSIONSToluene exposure increases risk of olfactory dysfunction in furniture workers. Olfactory function testing should be considered for initial screening or periodic testing of furniture workers. Low toluene levels with a high proportion of olfactory dysfunction indicate that olfactory dysfunction is an early negative impact of chemical inhalation. Keywords