Oil spill accident from steel mill was caused by flood in August 2019 in Saga Prefecture, Japan. Since "oil odor problem" was happened in disaster area, the source estimation of oil odor was conducted using sensory evaluation and Gas Chromatography-Olfactometry (GC-O). By the sensory evaluation, the odor in disaster area was assigned as "odor of oil and sewage". To know in detail of the oil odor, environmental samples (oil absorption sheets) were collected and sensory compared with several fuel oils. As the result of evaluation, oil odor in 7 days after accident consisted of diesel oil (with/or kerosene) instead of spilled oil from steel mill. This result suggested that those fuel oils were also spilled from various sources (heating fuel for house and agriculture) around this disaster are during this flood. On the other hand, the oil absorption sheets in 12 days after accident did not showed odor of those fuel oils, and it showed weak odor of spilled oil from steel mill. It could be due to that these fuel oils spilled were evaporated within a few days under the summer weather, but spilled oil from steel mill which had heavier property was kept in environment.
