Evaluation of occupational exposure to formaldehyde from selected manufactures of dinnerware melamine productionin Tehran

Melamine formaldehyde resin is proposed as commercial material in the industry such as melamine dinnerware manufactures. Formaldehyde is produced under the pressure and temperature in this industry. Because of heath hurdle, the aim of this study was to conduct a thorough occupational monitoring of formaldehyde exposure in the dinnerware manufactures and quantitative risk assessment for control measuring. 54 workers from 4 melamine workshops (A, B, C, D) in Tehran were investigated) according to the NIOSH method No. 3500. Atmospheric condition including air temperature, pressure, the speed and relative humidity were measured. Quantitative risk assessment was conducted using the method of IRIS. Results were analyzed with SPSS statistical analysis software. Formaldehyde exposure in workers was evaluated 0.094 ± 0.033, 0.091 ± 0.028, 0.048 ± 0.015 and 0.121 ± 0.049 ppm in the A, B, C and D workshops, respectively. There are positive correlation between temperature and occupational exposure significantly. Pressing workers were exposed to maximum concentration of formaldehyde while grinding have minimum exposure. Result of risk assessment in the four melamine manufactures are different (P=0.002). All workers exposure to formaldehyde are higher than the Time-weighted average TWA=0/016 ppm suggested by NIOSH and lower than the Time-weighted average TWA=0/75 ppm suggested by OSHA. The results of this study are comparable with other studies. Occupational monitoring and risk assessment remind occupational hazards of melamine dinnerware manufactures. Then, this study suggest further justify proceeding and engineering control measures.