ABSTRACT: Objectives: The purpose of this study was to investigate formaldehyde migration from the use of urea plastic bowl, a popular container used widely in Thailand. Materials and Methods: Samples of urea plastic bowls were collected to determine levels of formaldehyde migration into instant noodles from the simulated situations in their use for instant noodle cooking and containing. The migration test was a factorial design with 5 replications for each experimental unit. Types of instant noodle, exposure times, and times of bowl use were three factors in this study. Results: The low pH ingredients and long exposure time with hot cooked instant noodles were important factors increasing formaldehyde migration. The highest formaldehyde migrating level of 5.01 mg/bowl occurred from the first time use of a bowl with 23 minutes of exposure time. The migration was found continually even though the bowl was used repeatedly until the 20th time of use. This highest formaldehyde migrating level is still safe compared with the total daily intake (TDI) as 9 mg/day for a 60-kg person. However, a chronic health hazard may occur when people eat minced pork tom yam or other sour flavors of instant noodles with urea plastic bowls more than other types of bowls. Conclusion: Formaldehyde migration occurred during the use of urea plastic bowls, especially, when the containers were exposure to hot acidic food over long exposure time. The highest migration was found beginning the first time use. Some suggestions include rinsing the urea plastic containers with hot water before the first use and avoiding consuming sour flavored instant noodles with urea plastic bowls more than one bowl daily to prevent chronic toxicity of migrating formaldehyde.
*Department of Environmental Health Sciences, Faculty of Public Health, Mahidol University,
**Department of Epidemiology, Faculty of Public Health, Mahidol University, Bangkok, Thailand