Abstract
Objectives: Two cross-sectional studies were undertaken on workers in a beverage processing plant to investigate the association between low H2O2 exposure and symptoms of irritation (2005 study) and to investigate the effect of wearing respiratory protection (2006 study). Methods: The study comprised 69 workers exposed to H2O2 in sterile chambers and 65 unexposed controls. The exposure was assessed from measurements and work task information from employment records. The severity of work-related symptoms was evaluated using questionnaires. Data were analyzed by the Student’s t-test, multiple linear regression and analysis of variance for repeated measures of symptoms. Results: Symptoms of eye, nose and throat irritation were significantly (P < 0.001) more severe among exposed workers compared to controls. Exposure values were occasionally above American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value–time-weighted average (TLV-TWA) in the sterile chambers. The relationship between the severity of symptoms and the number of entrances in the chambers was significant (P < 0.0001) in 2005 but not in 2006, when respirators were used during work in the sterile chamber. No differences were found between exposed who entered a sterile chamber in 2005 but not in 2006 and exposed who entered a sterile chamber both in 2005 and 2006. This suggests that respirators provided an efficient protection and that the irritative effects of exposure to H2O2 in 2005 did not disappear after 1 year. Conclusions: The source of risk was exposure in the sterile chamber, even though the time of exposure was generally only ∼30 min. To ensure complete worker protection, there is a need for a short-term exposure limit for H2O2 in addition to the existing ACGIH TLV–TWA value.