There is a possibility that the explosion was due to a buildup of fumes from the diffuser.
Associate Professor Gao Zhiqiang from the Department of Chemistry at NUS Faculty of Science said, "Usually, aromatherapy is used in a closed room. This could mean vapour build-up in a closed space.The gases in the surroundings within the space could have become flammable with the change in chemistry during the therapy, and a spark could result in an explosion or flash fire in seconds."
Mr Mohd Rizalludin Hassan suffered 80% burns on his body after the explosion.
There has been no complaints with the Consumers Association of Singapore about faulty essential oil diffuser devices in the last 3 years.