BIOLOGICAL MONITORING OF TRIETHYLAMINE AMONG COLD-BOX CORE MAKERS IN FOUNDRIES

Objectives: The objectives of the study were to assess triethylamine ( TEA) exposure in cold-box core making and to study the applicability o f urinary TEA measurement in exposure evaluation. Methods: Air samples were collected by pumping of air through activated-charcoal-filled gl ass tubes, and pre- and postshift urine samples were collected. The TE A concentrations were determined by gas chromatography. Design: Tea wa s measured in air and urine samples from the same shift. Breathing-zon e measurements of 19 workers in 3 foundries were included in the study , and stationary and continuous air measurements were also made in the same foundries. Pre-and postshift urine samples were analyzed for the ir TEA and triethylamine-N-oxide (TEAO) concentrations. Results: The T EA concentration range was 0.3-23 mg/m(3) in the breathing zone of the core makers. The mean 8-h time-weighted average exposure levels were 1.3, 4.0, and 13 mg/m(3) for the three foundries. Most of the preshift urinary TEA concentrations were under the detection limit, whereas th e postshift urinary TEA concentrations ranged between 5.6 and 171 mmol /mol creatinine. The TEAO concentrations were 4-34% (mean 19%) of the summed TEA + TEAO concentrations. The correlation between air and urin e measurements was high (r = 0.96, P < 0.001). A TEA air concentration of 4.1 mg/m(3) (the current ACGIH 8-h time-weighted average threshold limit value) corresponded to a urinary concentration of 36 mmol/mol c reatinine. Conclusions: The TEA exposure levels of foundries and their core makers vary greatly. Stationary air measurements in factories ar e not sufficient to assess TEA exposure; instead, personal sampling is needed. The biological monitoring of TEA in postshift urine samples p rovides a practical and accurate method for assessing exposure.