This study aimed not only at describing the typical morning or night features of a group of shift workers in a chemical industry, but also at identifying possible links between work shifts and chronotype. This study was held in a two-shift-chemical industry located in the interior of São Paulo. The subjects of our research were the 44 men and women working there either in the morning or at night. The data was collected through the Brazilian version of the Horne & Östberg chronotypes identification questionnaire. The "moderately morning" chronotype was predominant - MM (47,73%), followed by the "indifferent" - IN (27,27%) and by the "definitely morning" - DM (22,73%). Only one of them could be considered a "definitely night" - DN (2,27%). The workers under study were predominantly classified as "moderately morning" followed by the "indifferent" and by the "definitely morning" chronotypes. No statistically relevant relationship was found between the chronotype and individual characteristics.
chronotype; shift workers; chronobiology
